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-   -   VTEC-E question, help! (https://www.fuelly.com/forums/f11/vtec-e-question-help-13198.html)

benfrogg 01-14-2011 11:25 PM

VTEC-E question, help!
 
93' civic vx. Federally.
So I've had a perplexing thing happen. This has happened before, but I didn't have a gauge to prove my theory.
After driving for about 24 miles, (it was -3at the start of my drive) I was traveling on a flat plane at 40 mph and holding 65mpg on the gauge. Suddenly, an increase in low end torque (I'd estimate about 1/4-1/3 more) and big increase in mpg's. The gauge shot up to 104mpg and stayed there. The car started to accelerate. I hadn't changed throttle position the whole time.
The rest of the drive home, I could hold much higher mpgs at higher speeds and with much less effort up hills. The remaining 10 miles raised my trip mpg by 7mpg's. (total about a 34 mile trip or so)

I have noticed this happen several times on long drives. After 15-20 miles all of a sudden I start getting much better torque without losing lean burn. I couldn't prove it was reality (and not my head) until I was staring at the gauge when it happened.


So, honda experts, what happened?!?!?

I'm thinking vtec. I'm going to head out to the garage now to test the electronics side of it and to pull the valve cover to inspect the components. I've been reading that if the solenoid fails, it fails in the "higher power" mode. That is to say, it fails in the more aggressive, 16valve mode as opposed to the less aggressive, better swirl, almost 12 valve mode. The ecu turns off the solenoid to achieve "higher power" mode. Is this true?
If so, it may explain the problem. However, I have not found any codes so that makes me confused. The book says it will show a code if it fails.

This brings up another question: If I unplug the vtec solenoid, would the car run all the time in the "lower power economy" mode?

So the big question is, is the problem mechanical or electrical or both?


Any other possible scenarios? Could it be something other than vtec? Could it be the ECU? I have a spare one of those I can swap in.
Thanks for the help!
B

benfrogg 01-15-2011 12:21 AM

Re: VTEC-E question, help!
 
Okay, three other things:
I was in 5th gear at the time of the incident.

Two:
I checked the electrical side of things from the haynes manual. The only thing that was supposedly wrong is that there is continuity between ground and the ECU side of the plug to the solenoid under the hood. (not the pressure switch) This connector has one single wire. In the key off position, ground is present. Is this right or sign of a short?

Three:
I have never felt what people call VTEC "engaging." That is to say, no sudden boost of power at 2k-redline. Even under full throttle in first gear all the way to redline (just got done seafoaming it) no sudden boost in power. Perhaps another symptom of a not working vtec system? Or a symptom of bad ecu? I haven't tested the ECU side of things yet.
B

GasSavers_Erik 01-15-2011 05:01 AM

Re: VTEC-E question, help!
 
If it was me, I'd unplug the vtec solenoid and go for a drive. See if you still get the burst of torque after 10 miles and monitor your mpg.

benfrogg 01-15-2011 07:28 AM

Re: VTEC-E question, help!
 
I tried that when I got home. No beans. Just a check engine light.

Here's my current theory:
The mechanical end of my vtec is stuck in 16v mode all the time. THis would explain the very low torque usually available at low rpms. I would explain the less than awesome FE. It would explain the rough idle.
So, to test this theory, all I need to do is pull the valve cover and spin the crank. If all 4 valves operate completely on all cylinders, I'll know the problem. However, it could be the oil pressure switch keeping it locked in 16v perhaps. If that was the case, it would only be evident if the car was running with the valve cover off. That would be messy but it would only take 5 seconds to determine if it were true.

Assuming it is true, then a long drive getting to full operating temp and keeping it there a while would somehow disengage back to 12v mode until the vtec system needed to be activated again (for instance if I needed to accelerate from a stop to 55mph going up a hill).
What could cause to stick? I'm going to start pullng it apart I guess. More input welcomed!
B

pgfpro 01-15-2011 09:58 AM

Re: VTEC-E question, help!
 
I wish I could be more help but I have never owned a VX. A friend of mine owned one about five years ago and was having issues with the VTEC solenoid. But as I remember it was stuck in 12v mode and had no power from 3000rpm on.

From what you describe it sounds like your diagnoses is right. Do you have a spare solenoid that you could block off the VTEC gasket oil filter screen to simulate a plug screen to see if you would have 12v mode all the time? For that matter even a spare VTEC gasket with the built in screen that you could block off.

Then if it went and stayed in 12v mode all the time you could rule out the mech. valve-train as the cause.

EDIT after reading your other post if the car change its power out put and fuel mileaged then the mech side of the valve train is working.

Sorry I need to wake up. More coffee.

GasSavers_Erik 01-15-2011 10:41 AM

Re: VTEC-E question, help!
 
I like the idea of doing a visual inspection with valve cover off/engine off.

If you are lucky- maybe your oil filler hole is on rear (intake side) of the head... That might allow you to peek through the hole and see the two adjacent intake rocker arms of one cylinder.

It looks like vtec-e uses oil pressure to open the 2nd intake valve (https://www.b18c5eg.com/VTEC/sohcvtece.html) - so keeping it from doing so would keep you in the economy high swirl mode as long as you didn't ever need the power.

The factory service manual says that the vtec spool valve should have a resistance between 14-30 ohms. So, you could go to radio shack and find a such a resistor and attach one end to ground and the other end to the wire from the ecu. This would not trigger a CEL.

About 10 years ago, I used a pair of radio shack resistors to keep the CEL off on my Acura Integra which had a bad idle air control valve (the engine would idle way too fast unless I unplugged the connector). I wasn't knowledgeable enough at the time to know I could remove it and clean the valve.

benfrogg 01-15-2011 11:57 AM

Re: VTEC-E question, help!
 
Okay, so, some updates.

I pulled the valve cover and spun the crank manually. All cylinders are operating in 3 valve (12 valve) mode with the engine off. I put the cover back on (more work than it sounds like; one of the head bolt threads I helicoiled broke in half at the casting. I had to drill it all the way down to the end of the hole and out the bottom. I then re-tapped it with a slightly smaller 1/4"x20 tap. I used a longer 1/4"x20 bolt and re-used the gasket/washer assembly (which I had to cut the bolt to get off intact) to secure it. Good news is, the valve cover doesn't leak anymore because I could finally put factory torque back on the bolt. Bad news is I have an sae bolt head on my valve cover now...

Anyway, through the oil fill hole I observe the number one cylinder's intake valves. Sure enough, only 1 is opening at idle. (12v mode) At least during revving with no load, it does not switch to 16v mode.
I went further and popped on a spare vtec solenoid I have. No change in driving characteristics that I can see. A curious thing though; that extra torque I got last night was not noticeable at idle. It was really only in 4th or 5th gear around 40 to 55 mph. I can't tell today if it's now got that better torque all the time because I haven't taken a highway drive (thus trying to maintain lean burn while ascending a small incline). Although, it does feel like it has that torque at that speed/gear now. I can't tell. I have a long drive tonight and will report back findings on that front.

I went further to install a 12v test light in the cabin of the car for the vtec solenoid. Sure enough, at 2500 to 3500 under heavy throttle, it lights up and seems to work. That implies that the electrical side of things is working just ducky.

I also took apart the rest of the spool valve. There is a spring in the bottom, a sliding pin that either lets oil past or not, and a small round fat washer looking thing with a hole in the middle of it that is not centered. I did just do a seafoam treatment including crankcase seafoam just prior to an oil change. Perhaps the sliding pin was stuck in the open position and is now free to move as it should? That's just speculation at best.
Another theory is that the spring may not be powerful enough (worn out) to keep the valve closed after it has been opened once by the solenoid. It seems to have enough energy to hold the valve closed, but I can't be certain. The parts motor will have a spool vale I can swap on to test this hypothesis.

Good idea on the resistor front. I'm thinking now that the electrical side of things is functional, but perhaps the mechanical side was up until recently not functional or that under high load (and thus high oil pressure) the solenoid may have opened on it's own without 12v thus activating 16valve operation.
Blocking off the orifice with something solid (like a fabricated alloy plate I could make and gasket material) would prove or disprove the oil pressure theory. Hmmm.
I'll post again after tonight's drive and give a synopsis.
Thanks for all the input!
B

benfrogg 01-15-2011 09:44 PM

Re: VTEC-E question, help!
 
Okay, so plot thickens.
On the drive tonight (40 miles each way) it was snowing heavily on the way there. It was also very windy (gusty, not one direction). The extra torque was there, no doubt. I used the block heater to bring the car up to operating temp beforehand. The traffic was heavy and traveling slowly then fast, etc. This trip was 63.3mpg.
On the way home, the car had to warm up on it's own. There was zero traffic. The speeds were about 5 mph faster overall. No snow coming down, the roads were clear as well. The new found torque, however, was absent until the last 3 miles of the drive. This pushed the FE down to 55mpg for the same trip in the opposite direction. No, there was no significant change in elevation from point at to point b.

So, I don't know what is different, but something sure is.
It's possible it has nothing to do with vtec but I really don't know. I have not yet looked in the valve cover and found two valves opening at idle. I've been checking consistently. I'll check it tomorrow at stone cold when oil pressures are likely highest.

What the heck else could cause this?
Maybe a cylinder not firing (or getting adequate fuel) during lean burn?
I'm totally out of ideas. Whatever it is, it is the cause of my less than stellar FE after all these mods and driving changes.
B

theholycow 01-16-2011 03:04 AM

Re: VTEC-E question, help!
 
Failing O2 sensor? Clogged catalytic converter? Sticky brake? Failing wheel bearing?

benfrogg 01-16-2011 05:53 AM

Re: VTEC-E question, help!
 
02-
Brand new NTK 24300

Clogged cat-
Maybe? Looks open when peering in through 02 sensor opening. Would this cause sudden changes in power?

Sticky brakes-
Nada. Checked and re-checked and re-checked. Checked hot, cold, warm, etc.

Wheel bearing-
Probably the most likely left of the culprits. Not unusual noise that I've heard. I'll keep searching for signs of it.

Thanks!
B

theholycow 01-16-2011 06:07 AM

Re: VTEC-E question, help!
 
Clogged cat, in this case, would be intermittent with something loose that sometimes blocks it and sometimes doesn't (probably related to thermal expansion)...no idea how you'd diagnose it.

pgfpro 01-16-2011 08:57 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157245)
Okay, so plot thickens.
On the drive tonight (40 miles each way) it was snowing heavily on the way there. It was also very windy (gusty, not one direction). The extra torque was there, no doubt. I used the block heater to bring the car up to operating temp beforehand. The traffic was heavy and traveling slowly then fast, etc. This trip was 63.3mpg.
On the way home, the car had to warm up on it's own. There was zero traffic. The speeds were about 5 mph faster overall. No snow coming down, the roads were clear as well. The new found torque, however, was absent until the last 3 miles of the drive. This pushed the FE down to 55mpg for the same trip in the opposite direction. No, there was no significant change in elevation from point at to point b.

So, I don't know what is different, but something sure is.
It's possible it has nothing to do with vtec but I really don't know. I have not yet looked in the valve cover and found two valves opening at idle. I've been checking consistently. I'll check it tomorrow at stone cold when oil pressures are likely highest.

What the heck else could cause this?
Maybe a cylinder not firing (or getting adequate fuel) during lean burn?
I'm totally out of ideas. Whatever it is, it is the cause of my less than stellar FE after all these mods and driving changes.
B

The only other thing I can think of is a bad CTS. It could be dropping down drastically from a warm up point to a cold point. You could monitor the 5 volt output back to the ECU to see if it drops a ton all at once.
https://www.fuelly.com/attachments/fo...6e27555342.jpg

The other thing it could be is a bad injector that is not flowing due to internal issues. This would make all the other three run extremely rich to make up for the bad injector because the O2 is reading all four as a whole and not each.

benfrogg 01-16-2011 10:59 AM

Re: VTEC-E question, help!
 
Forgive me, what does the acronym CTS stand for? I'd be happy to monitor it if I knew what it was!

The injector idea is certainly possible. I have now have 8 spare injectors. I'm going to clean them with a syringe and carb cleaner and see which ones flow best when done. I'll swap them in and verify there's no problems there.
It could still be the harness, I suppose, as well.

I've been reading around on the web and this issue appears common. Other people document the same symptoms; you can barely hold 55-60mph in lean burn and every once in a while on a long drive it all of a sudden is easy to. I'm going to recheck my EGR ports/valve tomorrow for grins.
I swapped a spare ECU (I now have two spares) and the same thing is happening.... interestingly, the idle is smoother with the new ECU. I don't know why that is.

I picked up a VX motor and tranny complete - the exhaust mani today. Best $100 I ever spent!

I am not ruling out clogged cat. I want to rule out all other possibilities first as that will be big money to replace.

I've got a host of testing I'm going to do tomorrow, I'll update.
Thanks!
Ben

pgfpro 01-16-2011 11:19 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157253)
Forgive me, what does the acronym CTS stand for? I'd be happy to monitor it if I knew what it was!

The injector idea is certainly possible. I have now have 8 spare injectors. I'm going to clean them with a syringe and carb cleaner and see which ones flow best when done. I'll swap them in and verify there's no problems there.
It could still be the harness, I suppose, as well.

I've been reading around on the web and this issue appears common. Other people document the same symptoms; you can barely hold 55-60mph in lean burn and every once in a while on a long drive it all of a sudden is easy to. I'm going to recheck my EGR ports/valve tomorrow for grins.
I swapped a spare ECU (I now have two spares) and the same thing is happening.... interestingly, the idle is smoother with the new ECU. I don't know why that is.

I picked up a VX motor and tranny complete - the exhaust mani today. Best $100 I ever spent!

I am not ruling out clogged cat. I want to rule out all other possibilities first as that will be big money to replace.

I've got a host of testing I'm going to do tomorrow, I'll update.
Thanks!
Ben

(CTS) Coolant Temperature Sensor Also know as a ECT Engine Coolant Temperature sensor.
See in my Neptune pic how the correction table works?

benfrogg 01-16-2011 11:23 AM

Re: VTEC-E question, help!
 
Does the coolant temp sensor also feed the dash? Or is it a separate sensor like many cars have?
I'll run the tests on it tomorrow and verity it's operation. I may actually just swap it out with one of my spares.
Thanks
B

benfrogg 01-17-2011 10:17 PM

Re: VTEC-E question, help!
 
So, I did some things today to the car:
Pulled and cleaned all 4 injectors. Swapped in one different injector because one of the ones on the car wasn't flowing well. It was almost not noticeable, and may well be in my head, but I figured it couldn't hurt to swap it with a known good one.
Pulled, tested, and cleaned the EGR valve.
Cleaned EGR ports again. No noticeable clogging to begin with.
Tested TPS cold and warm. Right at spec.
Tested CTS. It was -2df when I started and my book only had readings for 50-70df. My ohms were very high, but that corresponds with what the book says is right. Higher the temp, lower the resistance. I tested it while warming it against my garage heater. It's resistance lowered. I swapped it with one from the new parts motor; they both had exactly the same readings.
Checked CKP, CYP, and the other sensor in the same harness. All were supposed to be between 350 and 700 ohms. Mine all tested at about 330-340. I ran the same test on both of my spare dizzy's. All had about the same results. I'm thinking it was due to the lower starting temperature. Should I be concerned about that?

I also finished my underbody paneling. Came out looking pretty good. I'll have to do some highway driving to see how effective it will be.

I drove about 20 miles around town/short highway doing some testing. Prior to that, I let the block heater run 2 hours. After the drive, the radiator hose feeding the thermostat was still very cold. It was obvious that the thermostat had not opened during the drive. I wonder if that is normal? Am I not making enough heat to keep the car at operating temp? My grill opening is only about 3"x4" right now.

Anyway, so, nothing really to explain my sudden torque/FE gains yet. Still open for suggestions. Looks like I may need to pull that cat at some point.
I'll also try to start documenting under what conditions the gains happen. Maybe that will lead to a cause.
B

imzjustplayin 01-18-2011 12:14 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by pgfpro (Post 157252)
The only other thing I can think of is a bad CTS. It could be dropping down drastically from a warm up point to a cold point. You could monitor the 5 volt output back to the ECU to see if it drops a ton all at once.
https://www.fuelly.com/attachments/fo...6e27555342.jpg

The other thing it could be is a bad injector that is not flowing due to internal issues. This would make all the other three run extremely rich to make up for the bad injector because the O2 is reading all four as a whole and not each.

which would then let the computer calculate the MPG as being very high since it uses the pulse width of the injector in order to calculate fuel economy. Maybe he has a sticky injector(s) and that is giving him more power while giving the perception of better fuel economy when in actuality it's no better. I mean to get 104mpg at a steady cruise makes no sense but due to the information given to the computer, that'd be the only conclusion it could come to.

OP, I'd just check every ground inside of the car and remove them, sand them down, clean them up and reattach them. Just did this with my portable phone today and not only do the keys work better (used q-tip+rubbing alcohol) but I also get a bit better signal (did it to where the antenna mounts).

theholycow 01-18-2011 02:28 AM

Re: VTEC-E question, help!
 
A sticky injector would not affect the pulse width of the signal that operates it, and therefore would not affect the FE reading. Nothing measures mechanical open time, just the signal that's used to operate the injector.

I can't imagine doing all that work in my snowy yard at -2?F.

GasSavers_Erik 01-18-2011 05:32 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157290)

I drove about 20 miles around town/short highway doing some testing. Prior to that, I let the block heater run 2 hours. After the drive, the radiator hose feeding the thermostat was still very cold. It was obvious that the thermostat had not opened during the drive. I wonder if that is normal? Am I not making enough heat to keep the car at operating temp? My grill opening is only about 3"x4" right now.

B

Since you drove for 20 miles, I think that you thermostat is coming open slightly- just enough to keep the engine at the proper temp. If you had your heater set on high and "hot" for the entire drive, then it was likely doing quite a bit of the engine cooling.

Even with the small grill opening, the radiator area is drafty and the high surface area of the rad does a great job at letting the coolant give off heat. So- it is very possible that the thermostat was open a small amount and the radiator was just getting rid of all of the heat so the small flow of coolant entering the engine was very cold.

pgfpro 01-18-2011 07:46 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by ************* (Post 157291)
which would then let the computer calculate the MPG as being very high since it uses the pulse width of the injector in order to calculate fuel economy. Maybe he has a sticky injector(s) and that is giving him more power while giving the perception of better fuel economy when in actuality it's no better. I mean to get 104mpg at a steady cruise makes no sense but due to the information given to the computer, that'd be the only conclusion it could come to.

OP, I'd just check every ground inside of the car and remove them, sand them down, clean them up and reattach them. Just did this with my portable phone today and not only do the keys work better (used q-tip+rubbing alcohol) but I also get a bit better signal (did it to where the antenna mounts).

I agree with this statement. Also I would like to add is check your injector wires back to the ecu. I ran into a problem with my sons civic last summer and it took me a week to diagnose it. It turned out to be an injector wire that was almost broke in half. It was at the kick panel where the wire harness does a 180 to the ecu.

benfrogg 01-18-2011 09:09 AM

Re: VTEC-E question, help!
 
HC-
If one injector wasn't working right, all other injectors would compensate because the 02 sensor would catch the lean or rich mix and adjust accordingly. So, if one injector was giving very little fuel, the ECU would see that as all cylinders running lean and enrichen the mixture. It's feasable to think it could cause something like this, I think.

I have a garage. It is not heated or insulated but I have a 40k btu propane heater. After about 2 hours of working out there, it's about 55ddf. Of course, the metal of the car probably never gets above 30df. It's do able. I used to do all my work outside and it sucked!

Erik-
Yes, I think you are right. I was using the hot setting on the heater, fan blower at 2. I just didn't know if there was any relationship to the power issue or not since the thermostat was certainly not full open or anything.

Pgfpro-
I've done most of the grounds under the hood already with additional 8g wire and a junction block. I'll have to dig through my book and find all the grounds in the cabin. I think the ground for the ECU is probably especially important. I'm sure it's never been done.

Testing the harness is a really good idea. I hadn't put much credence in it yet, but it's looking more possible. I have to get a long test lead with some gator clips made up today and I'll test all wires; not just signal wires but ground as well.
What were your symptoms when your harness had a break in it? Were they similar to mine or just no fire injector?

I'll look in my book for what pins are the injectors on the harness. I doubt they are the same color back at the ECU as they are at the block.


I really wish one of you lived close enough to drive this car and tell me if it drives like it's supposed to. It just doesn't seem right that on the highway at 60mph, I can't hold lean burn without losing speed if there's even the slightest incline. I usually let it drop down to about 50 to see if I can keep lean burn. Anything under 45mph is illegal here on the highway.
Thanks
B

pgfpro 01-18-2011 01:07 PM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157306)
HC-
If one injector wasn't working right, all other injectors would compensate because the 02 sensor would catch the lean or rich mix and adjust accordingly. So, if one injector was giving very little fuel, the ECU would see that as all cylinders running lean and enrichen the mixture. It's feasable to think it could cause something like this, I think.

I have a garage. It is not heated or insulated but I have a 40k btu propane heater. After about 2 hours of working out there, it's about 55ddf. Of course, the metal of the car probably never gets above 30df. It's do able. I used to do all my work outside and it sucked!

Erik-
Yes, I think you are right. I was using the hot setting on the heater, fan blower at 2. I just didn't know if there was any relationship to the power issue or not since the thermostat was certainly not full open or anything.

Pgfpro-
I've done most of the grounds under the hood already with additional 8g wire and a junction block. I'll have to dig through my book and find all the grounds in the cabin. I think the ground for the ECU is probably especially important. I'm sure it's never been done.

Testing the harness is a really good idea. I hadn't put much credence in it yet, but it's looking more possible. I have to get a long test lead with some gator clips made up today and I'll test all wires; not just signal wires but ground as well.
What were your symptoms when your harness had a break in it? Were they similar to mine or just no fire injector?

I'll look in my book for what pins are the injectors on the harness. I doubt they are the same color back at the ECU as they are at the block.


I really wish one of you lived close enough to drive this car and tell me if it drives like it's supposed to. It just doesn't seem right that on the highway at 60mph, I can't hold lean burn without losing speed if there's even the slightest incline. I usually let it drop down to about 50 to see if I can keep lean burn. Anything under 45mph is illegal here on the highway.
Thanks

B

The symptoms were a very light miss-fire then every once and while it would drop the cylinder and become a full time miss-fire. The Neptune told us it was an injector miss fire so we change the injectors then realized the symptoms didn't go away. So that's when we starting looking into the harness being the culprit.

I wish you lived closer to. I could hook up my P28 ECU with Neptune management with the wideband data-logging and run some diagnostic tests to see whats going on.

benfrogg 01-18-2011 01:20 PM

Re: VTEC-E question, help!
 
So, more time in the garage-
Checked continuity between injector and ECU. The 12v lines all have 12v all the time. With the key off, they have 5ohms or so resistance to ground.
The ground wires coming from the ECU all have great continuity to the plug at the ECU. I took each wire and bent it, stretched it, etc while doing the test. No breaks internally that I can find.
I also swapped in my third ECU I have. No change there either.

Pgfpro-
Can ECU's be reprogrammed or chipped to run at leaner values? Is this something you can do? I've got a couple of spares to do the work to if it is possible.


I guess I'm going to have to buy a fuel pressure gauge. I'm thinking the fuel pressure regulator might be dying? If there was low/intermittent pressure at the fuel rail, I could see this problem happening, maybe. My old GM cars wouldn't start with anything less than full pressure at the rail. I'm guessing hondas will run with low or intermittent pressure?
I have already swapped out the fuel pump with one from the parts car. No change in operation. That leads me to the FPR. Come to think of it, I may have a spare one of those too. I'll scower my garage later tonight for it.


Next time I'm headed on a cross country trek, I'll make a stop in Idaho! That's not going to happen anytime soon, but who knows. Anyway, thanks again for all the help!
B

benfrogg 01-18-2011 01:28 PM

Re: VTEC-E question, help!
 
Another thought, after reading your symptoms, is that I was having a very random misfire before the new plug wires. It would happen so seldom that it was almost not noticeable. Maybe once in 400 miles or so would I notice it.
I tested the life of the ignition components-
I ran a 4g wire from battery ground into the cabin. I ran a 4g wire stuffed into the number one cylinder plug wire into the cabin. I started the motor on 3 cylinders and slowly pull the two leads apart until the spark wouldn't jump any more. (I didn't let it fire with nothing thus burning up the coil/ignitor) I got almost an inch of spark jump.
Maybe I can swap on the old/new dizzy.
B

imzjustplayin 01-18-2011 03:33 PM

Re: VTEC-E question, help!
 
maybe check the crank sensor... or try driving with the ELD detector disconnected or the alternator disconnected and see if that does anything. That whole "104mpg" thing really leads me to believe that there is some device in there that would possibly be doubling the RPMs or halving the RPMs the engine is spinning at, making the computer think it's using less fuel than it is. The reason I bring up the alternator and the ELD detector is that maybe after everything is warmed up in the engine bay, things start to fail or partially fail and it may be screwing with the computer or other electronics.

benfrogg 01-18-2011 04:08 PM

Re: VTEC-E question, help!
 
The MPGUIONO routinely goes to the 150-250mpg range. Usually when slightly decelerating and not DFCO. I was on a level plain, slowing down slightly, when the gauge jumped to 104 and I got more torque. I then was able to give more throttle to keep the vehicle at speed and accelerate to the speed limit and the gauge went down to like 75mpg steady at 50ish mph. I'm assuming with all of my mods that should be about right all the time at 50mph assuming I'm on level ground with little headwind.

I assume the ELD means electric load detector? Where is it?

The mpguino uses a VSS off of the transmission, not the engine. The only other information is from the ECU lead of the injector itself.

B

imzjustplayin 01-18-2011 04:16 PM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157321)
The MPGUIONO routinely goes to the 150-250mpg range. Usually when slightly decelerating and not DFCO. I was on a level plain, slowing down slightly, when the gauge jumped to 104 and I got more torque. I then was able to give more throttle to keep the vehicle at speed and accelerate to the speed limit and the gauge went down to like 75mpg steady at 50ish mph. I'm assuming with all of my mods that should be about right all the time at 50mph assuming I'm on level ground with little headwind.

I assume the ELD means electric load detector? Where is it?

The mpguino uses a VSS off of the transmission, not the engine. The only other information is from the ECU lead of the injector itself.

B

Oh, see that clarification helps A LOT!!! So you were getting 75mpg cruising at around 50mph? That's exactly where you should be at. You know what? I think I know what your problem is and I'm thinking it's not really a problem. There are various temperature sensors located in the car which send information to the ECU, if the computer thinks it's too cold, it won't enter into its most efficient mode. I'm surprised you're detecting the lean burn as working prior to this but I guess it's possible it's able to enter lean-burn while not being in ideal conditions.

It's really too bad that the MPGUINO doesn't have other information like engine temperature, map sensor information, etc. If you were able to use a Scan gauge, you'd definitely have this info but since you're OBD-I, information is likely to be scarce unless you had a programmable ECU but these Lean-burn ECUs are special and don't lend themselves to that.

pgfpro 01-18-2011 05:20 PM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157310)
So, more time in the garage-
Checked continuity between injector and ECU. The 12v lines all have 12v all the time. With the key off, they have 5ohms or so resistance to ground.
The ground wires coming from the ECU all have great continuity to the plug at the ECU. I took each wire and bent it, stretched it, etc while doing the test. No breaks internally that I can find.
I also swapped in my third ECU I have. No change there either.

Pgfpro-
Can ECU's be reprogrammed or chipped to run at leaner values? Is this something you can do? I've got a couple of spares to do the work to if it is possible.


I guess I'm going to have to buy a fuel pressure gauge. I'm thinking the fuel pressure regulator might be dying? If there was low/intermittent pressure at the fuel rail, I could see this problem happening, maybe. My old GM cars wouldn't start with anything less than full pressure at the rail. I'm guessing hondas will run with low or intermittent pressure?
I have already swapped out the fuel pump with one from the parts car. No change in operation. That leads me to the FPR. Come to think of it, I may have a spare one of those too. I'll scower my garage later tonight for it.


Next time I'm headed on a cross country trek, I'll make a stop in Idaho! That's not going to happen anytime soon, but who knows. Anyway, thanks again for all the help!
B

I sold all my chip burning equipment.

What I would do if I were you and I'm considering doing this myself is run a Moates Ostrich and socket one of your ecu's. Then run CROME (its free) and create your own fuel and timing tables. Then you can tune all the time and create the perfect tune.

If fuel goes past 95 a barrel I'm selling the Talon and buying another Honda with a VX engine and trans. Then I'm going to run a mitz 14b turbo and a small intercooler. A turbo on a VX engine would be the ultimate for me:)

imzjustplayin 01-18-2011 05:47 PM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by pgfpro (Post 157324)
I sold all my chip burning equipment.

What I would do if I were you and I'm considering doing this myself is run a Moates Ostrich and socket one of your ecu's. Then run CROME (its free) and create your own fuel and timing tables. Then you can tune all the time and create the perfect tune.

If fuel goes past 95 a barrel I'm selling the Talon and buying another Honda with a VX engine and trans. Then I'm going to run a mitz 14b turbo and a small intercooler. A turbo on a VX engine would be the ultimate for me:)

You can't use chrome on these ECUs and considering that the P07 ecu is far more complex than the other ECUs, I would say there is good reason for it. I don't believe it's a good idea to run the car lean just because the car is at a certain load and temperature, everything should be working and other factors we're not considering need to be considered which is what the stock ECU does and so you'll never be able to program the other ECUs to do what the stock ECU does since it's so complex. But what do I know, neither I nor anybody else has really dug into these ECUs. Something about "partial truths" and whatnot apply to the P07. I have to wonder if the HX's Lean-burn ECU is a refined version of this ECU or if they went back to a more basic version...

Btw, where did you get that chip burning equipment? I've got an older computer that I need to reflash the bios manually since I misflashed it but I need a "chip burner" I'd suppose in order to do this.

benfrogg 01-18-2011 06:07 PM

Re: VTEC-E question, help!
 
75mpg on a flat at 50mph was ONLY when this sudden bit of torque happened. I only noticed this happen during long trips even in summer. The problem is, the majority of the time, 50mph on a flat is only 53ishmpg instant. That means I have to do tons of EOC and such to get it above 53mpg tank.

What sensors are we talking about? Obviously CTS, IAS, but what else? I used to run a WAI that pulled in about 100df air all the time after warm up. I could tell I had less HP/torque to work with. I pulled it out to test the difference without. I need to get a test route and do some ABA with it. Don't forget, I'm probably hauling 200#'s or so of drum gear about 2/3 of my driving. I always unload when I don't need it.
If the car would keep that better torque all the time, I could easily run the WAI. Ironically, if your theory is true, the WAI would be the only thing to get me into that better torque/mpg's.

I'm still going to swap the FPR tomorrow on it to see if it changes anything. Can't hurt.

THanks for the info on ECU reprogramming. I just really want to get this thing doing what I think it is supposed to do.
B

benfrogg 01-18-2011 06:17 PM

Re: VTEC-E question, help!
 
Wouldn't getting into actual lean burn lower torque and raise MPG's?
That suggests that my extra torque had to have been coming from some other source. So, we are back to a couple possibilities:
Clogged cat
FPR
Other Sensors that have not been tested
?
B

GasSavers_Erik 01-19-2011 05:16 AM

Re: VTEC-E question, help!
 
You may be able to test the FPR by just disconnecting the vacuum line and see if the engine idle speed changes (when you do this fuel pressure will increase so technically it should richen the mix).

The FPR would explain the paradox (higher mpg AND more power). If the fuel pressure went up suddenly, the injector pulse width would remain the same (so the computer would calculate the same mpg) but the mix would be richer so you would feel more power and may need to let off the gas pedal a bit. At this point, the ECU would put you in lean burn mode (but you are really running rich because of the overly high fuel pressure).

So you would feel more power and see high mpg on the display because the injector pulses would be pretty narrow. If it was the FPR- you would also see a big difference when you fill up because the fuel used on the scangauge would not match the fuel you actually burned.

pgfpro 01-19-2011 06:18 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by ************* (Post 157325)
You can't use chrome on these ECUs and considering that the P07 ecu is far more complex than the other ECUs, I would say there is good reason for it. I don't believe it's a good idea to run the car lean just because the car is at a certain load and temperature, everything should be working and other factors we're not considering need to be considered which is what the stock ECU does and so you'll never be able to program the other ECUs to do what the stock ECU does since it's so complex. But what do I know, neither I nor anybody else has really dug into these ECUs. Something about "partial truths" and whatnot apply to the P07. I have to wonder if the HX's Lean-burn ECU is a refined version of this ECU or if they went back to a more basic version...

Btw, where did you get that chip burning equipment? I've got an older computer that I need to reflash the bios manually since I misflashed it but I need a "chip burner" I'd suppose in order to do this.

My Bad. I haven't had my hands on a FED VX PO7 just the Cali-Spec PO7 which is like the P28 (11FO or 1720 board) The internal wideband would be a problem on the FED VX board. Sorry to the OP for high jacking the thread.

benfrogg 01-19-2011 08:57 AM

Re: VTEC-E question, help!
 
Thanks for the ECU info. It's at least good to know that it isn't possible/feasable.

Is there any other way to test the FPR without a gauge? My book has only info on testing it with a pressure gauge.
I pulled the vacuum line, rpms increased but when I plugged the vacuum leak they went back down to normal. I put a manual suction on the FPR while blocking the vacuum hose coming from the IM. THis did nothing to change rpms or anything.
Unfortunately, neither or my parts motors came with the FPR. I think they are like $75 to replace, so I don't want to replace it unless I know for sure it is bad.
Maybe a fuel pressure gauge would be cheaper....
B

theholycow 01-19-2011 09:32 AM

Re: VTEC-E question, help!
 
I don't know if it would work with that engine but the $20 high-pressure fuel system tester (just a pressure gauge) works great on my GM V8.
https://www.harborfreight.com/fuel-in...ter-92699.html

imzjustplayin 01-19-2011 11:01 AM

Re: VTEC-E question, help!
 
There is one more (or two) sensors you may not have considered and especially in this way.. The O2 sensor... It's possible that before you get this better fuel economy and more power, you're stuck in open loop mode, for what ever reason. So here is what I want you to do. I want you to first inspect your exhaust manifold/catalytic converter, see if there is any rust. Then take off your exhaust up to the point of the last o2 sensor. Then remove the O2 sensors and inspect where they screw in. If you can, take pictures of all the rust you see, the bolts that go into the block, the holes the O2 sensors screw in and maybe other stuff. Then get a stiff brush and remove all the rust you see in the threads where the O2 sensor screws in, the rust where the bolts go through the manifold and then into the block, the bolts themselves etc.

Why am I suggesting this almost unheard of suggestion? You might not be aware but the body of the O2 sensor, the part that screws into the manifold itself is actually used with the O2 sensor for getting signal, and or providing ground power. When I've had to test O2 sensors, I specifically had to hook up a probe to the body of the o2 sensor and to one of the wires to get any signal (at least with a 4 wire). So it's still conceivable to me that this still applies. Anyway my point is, because of the rust, this could be affecting the way the O2 sensor either heats up or sends signal to the ECU. So my solution is to ensure there is a good path of continuity from the O2 sensor all the way to ground. This means removing rust from where the O2 sensor screws in, on the part of the manifold where the bolts go through into the block and the bolts themselves. Since you live in Maine, it's very unlikely for you to NOT have rust which is why I make this suggestion.

benfrogg 01-19-2011 02:33 PM

Re: VTEC-E question, help!
 
Yes, indeed, the whole maniverter where the 02 sensor is housed is rusty. It's cast, so it's not going to rust off or anything, but it has a lot of surface rust. I will pull it tonight and clean it/where the manifold hooks to the block and the like. Additionally, I may try to find a way to ground the sensor body itself... not sure how just yet, but I'll put my mind to the grindstone.
I didn't know that even the 5 wire sensor uses the manifold as ground.
Thanks for the tip.
B

imzjustplayin 01-19-2011 03:55 PM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157349)
Yes, indeed, the whole maniverter where the 02 sensor is housed is rusty. It's cast, so it's not going to rust off or anything, but it has a lot of surface rust. I will pull it tonight and clean it/where the manifold hooks to the block and the like. Additionally, I may try to find a way to ground the sensor body itself... not sure how just yet, but I'll put my mind to the grindstone.
I didn't know that even the 5 wire sensor uses the manifold as ground.
Thanks for the tip.
B

I can't confirm this with the 5 wire and or even any other O2 sensor, but when I've done O2 sensor testing, I had to use the body of the sensor itself in order to get a reading. I don't own any 5 wire o2 sensors nor do I own a VX lean-burn civic but I have spent plenty of time researching this vehicle as I was planning on doing a swap with its engine into a 4 door 92-95 civic but instead choose to go the HX route and swap that into my '98 4 door civic. Be sure to take some pics before you hook the manifold back up.

One easy tip for getting rid of rust on stuff like Steel/Iron is to submerge it in CLR and clean it with a tooth brush. I had a stove in my house that was rusting and arcing due to the lack of grounds (chassis was rusted), so I took the stove apart and submerged the parts in CLR for a few hours, scrubbed with a tooth brush and ONLY the rust came off! Don't use CLR on aluminum, I think CLR is muriatic acid and muriatic acid will have a violent reaction with aluminum IIRC. Also I wouldn't use the CLR where it could get in contact with the catalyst/catalytic converter since I have no idea what kind of reaction it will have.

benfrogg 01-19-2011 05:04 PM

Re: VTEC-E question, help!
 
Well, I did clean the maniverter hole with a wire brush drill attachment. I also attached a ground lead to a manifold bolt.
Here's a photo:
https://www.fuelly.com/attachments/fo...800a37ba4f.jpg
And here's where all the grounds meet the battery:
https://www.fuelly.com/attachments/fo...cd7a37fe71.jpg

For grins, I replaced the fuel filter. It's only been about 20k (or less) miles since the last one, but I did do a fuel tank replacement a while back. It was rusty on the outside enough to be leaking.

The initial road test seems promising. The car does appear to have a little less hesitation and get up and go when it is warmed up. (probably mostly in my head) I'll know more tomorrow during a 65 mile trip I have to make including some highway. I'll give an update.
It seems either the 02 grounding issue or the fuel filter might be the issue.

B

imzjustplayin 01-20-2011 12:55 AM

Re: VTEC-E question, help!
 
Quote:

Originally Posted by benfrogg (Post 157355)
Well, I did clean the maniverter hole with a wire brush drill attachment. I also attached a ground lead to a manifold bolt.
Here's a photo:
https://www.fuelly.com/attachments/fo...800a37ba4f.jpg
And here's where all the grounds meet the battery:
https://www.fuelly.com/attachments/fo...cd7a37fe71.jpg

For grins, I replaced the fuel filter. It's only been about 20k (or less) miles since the last one, but I did do a fuel tank replacement a while back. It was rusty on the outside enough to be leaking.

The initial road test seems promising. The car does appear to have a little less hesitation and get up and go when it is warmed up. (probably mostly in my head) I'll know more tomorrow during a 65 mile trip I have to make including some highway. I'll give an update.
It seems either the 02 grounding issue or the fuel filter might be the issue.

B

If this solves your problem or at least helps a lot, do you promise to do a better job of getting rid of the rust? All the points where the O2 meets with the manifold, the bolts that go into the block, the part of the manifold where the bolts are pressed against in order to attach to the manifold, and I guess the other side of the manifold which meets with the engine itself. Maybe you could soak like the top half of the manifold in some CLR, wait like a few hours, scrub with tooth brush until the rust is gone, all the while making sure the catalyst doesn't get wet (upright), then dry it all out and while it may end up black, it'll be rust free!


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