History of my 92 VX troubles (and help request)
 

History of my 92 VX troubles.

First off the guy that I got the car from totaled it (front passenger side) bought it back from the insurance company and Tried to put it back together. He did an OK job but due to PA DOT being dicks he failed when he sent in his application for a Salvage Title. It sat in his mother?s yard for about 1 ? years before I bought it.

It had about 174,000 miles on it.

When I got it ran terrible due to the old gas in it. I topped the tank off with super.

Once that tank was gone I replaced the front strut that was fubar. Seafoamed it, Changed the oil and filter, air filter, Battery, Distributor cap and rotor, brakes, Alternator (that lit on fire), plugs and wires. I ran Chevron Tecron twice and ran the Honda fuel service spray in the intake twice. I took the idle control valve off and cleaned it. I also checked the timing.

I did get a CEL 48 and 17. When doing the trouble shooting as per Haynes Manual they came out as ?intermittent? and don?t worry about it. I replaced the o2 sensor with a genuine Honda part and since have not seen any CEL?s nor have I seen any improvement.

Here is my problem as you can see by my gas log I get crappy mileage even with conservative driving. I drive this similar to my CRX that it replaced and I was getting almost 50 MPG on that. It idles terrible at best it jumps from 1000 rpm to 1600 and back about every 3 to 5 seconds. The other problem I have is that at certain points in the throttle I actually bog down and loose some power when pushing in the gas peddle (normally just a bit it is not like I am flooring it) I have to really push in the gas to ?get past? that or let the gas out totally and try again. Similarly if I bump start in 3rd gear at say 35 mph on a slight upgrade and hit the gas it will bog down sometime bog down a lot.

On my list of soon to do?s are:

Hook up the DMM to monitor lean burn to see if that is working.
Pull out Idle Control Valve and clean it again.

If anyone has any other suggestions please let me know. I have become totally frustrated with this car. I bought it with full expectation of improving on my 50 mpg from my CRX by 10 mpg not loosing 10.

Thanks in advance for the help,

Jack

Idle issues can be caused by a vacuum leak, so I'd check all of your vacuum lines and replace them if need be. Cars this old can have this problem, especially if it was not being used.

I would also check your TPS sensor, as it may need to be replaced. I can get you one for cheap, unlike Honda which does not sell this part by itself (they expect you to buy a new throttle body, which is less than cost-effective).

My money is on a vacuum leak, however. A good way to check is to get some starter fluid and spray it around the vacuum hoses while the car is running. if the idle surges in a particular spot, that is where your vacuum leak is.

Once you have tried these things, we'll know where to go from there.

BTW, an alternator catching fire is kind of scary!

My car bogged the way you described when I had my vacuum leak. It also caused a rich condition (the leaking hose was to the MAP sensor), and mileage plummeted (could see it on the SG1). The spark plugs were black with soot within half an hour of running it like this - though it was an extreme leak.

Just FYI.

Hope you figger it out.

Ok I will give that a try and let you know how it goes.

Ya lucky for me I was still there after I reconnected the battery or I would have burned that baby down.

TPS Sensor is a great place to start, let me know if you need the offical Honda procedure for tesing it. I have the Helms in PDF format and can send it to you. The other things to check out are the timing (both the distributor and cam timing) Distributor timing should be set at 16 deg BTDC. Also, the code 17 is for the VSS... Check the electrical connection on the sensor for corrosion and to make sure that the VSS is fully seated and getting the proper voltage and ground. Also make sure that there is sufficient grounding in the engine bay. You should have the ground from the battery to the shock tower, one from the transmission to the chassis, and one from the head to teh chassis near the drivers headlight. Also check to make sure the wire harness is grounded at the thermostat housing on the back side of the motor. Make sure that you have the proper spark plugs in there. They're not the same as the other honda plugs. They are a BRK4RF-11 IIRC, the main thing is they are a heat range of 4 not the 5 that other honda motors run. I had the same bogging problems when I bought my VX because of the 5 heat range plugs were in the car. Check your compression numbers as well and post those up. Cleaning the EGR system with carb cleaner or even EASY OFF oven cleaner will help things as well.

Try those things and get back to me. Also, check your ECU (in the passenger kick pane) and make sure it's a P07 (just somethings to make sure that you have the proper ECU running the car).

Make a intake manifold leak tester
It is very very simple and easy to make

https://www.mirage-performance.com/Ec...aks/index.html

Just hook it up to an air compressor/ bike pump
Pump the air into the intake manifold, and then spray windex on the manifold/hoses and watch for bubbles

No bubbles/ no leaks

Hooray

I have the same idle problem, But i feel like it is due to my egr not being connected. Which will be fixed soon. and I will let you know.

I forgot to also add: Check to make sure that none of your brakes are hanging up. Easiest way to check is to go for a drive that involves some braking. When you get to your destination, use your hand or a infrared thermometer to check the tempurature of each wheel. The fronts should be the same temp and the rears should be the same temp. If you have one wheel that is a lot warmer than the other, that is your hanging brake. This also works to find out if you have a caliper that is seized open as it will have quite a bit lower temp.

Jeez I had to print that so I could figure it all out. Ok here are my answers

PDF Helm... I have one (I think it is the one eveyone has not chaptered in anyway) It has the big "smudge" on the first page. I downloaded that before I even picked up the car.

Grounding I replaced the ground wire that attaches near the driver headlight. I will check the rest.

I did put in the "vx" plugs.

I am pulling out the ECU this weekend to hook up the lean burn monitor and will double check it is a P07.

The VSS I did the trouble shoot on that as per Helm's and it was ok (or intermitant). I only got that code once and it never came back.

EGR system (do you mean valve?)

I will get the compression numbers and do the TPS trouble shoot.

Thanks,

Jack

Ok no vaccum leak. Or at least not one that sucked in any of 1 and 1/2 cans of starting fluid.

How much do you want for the TPS? If it is cheap enough I will just toss in a new one.

Thanks,

Jack

Sorry, Jack, when I get going on diagnostics I can get long winded.

Ok that is great that you got all that other stuff checked so that stuff is out of the way.

EGR System, yup, I meant clean the whole EGR system. The Valve, and the ports (as best you can) unless you get the EGR kit from Honda. With taht kit, you can remove the aluminum "lumps" in the intake manifold and clean the EGR passages. Otherwise you can try to spray carb cleaner into the ports as best you can and drive the car around. The manifold vacuum will be enough to pull the carb cleaner through the ports if they aren't totally clogged.

I'll keep this one short so you don't have to print it out :o

Looking forward to your compression numbers as I need to do the same test on my VX motor that has about 316K miles on it now.

PS- be sure to do that brake check that I added up a couple posts as well. It's always good to get teh easy things out of the way.

Ok here is my update. I pulled my ECU it is the P07. I also soaked my ICV in throttle body cleaner for a few hours. It didn't fix my idle problem but it is better. Also my muffler 1/2 fell off so I pulled it the rest of the way off and ordered a new one.

I will get the compression test done once election day has passed. Until then there is just too much stuff to do.

Here are my compression numbers...... 160 right across. Well the rules that out.

I think I'm having simaler problems with idle bounce, I plan to check again for vaccum leaks, my only thought is that my PCV system might have a leak, it's so hard to get to that lower hose, I have a new grommet and everything, I just can't get in there with my big hands, I'll try cleaning my ICV as well and see what that does, it sounds like I'ver replaced all the exact same things as well, and each one helped, but didn't solve the problem, and there isn't that much left.

I think you would find that there was a small vac port that was blocked with the goop.

A reduction of the intake size by the amount you said shouldnt affect anything ,,and if it did ,it would be during wide open throttle positions where the restriction restricts air flow , not during mid speed cruise conditions where the air flow volume is MUCH less.

If you sure that no vac ports were blocked , then the only other idea that I have is that if the goop was thick right up to the butterfly that could cause a problem.

If the throttle was partly open (during cruise) the throttle position sensor would see it but the air could be blocked or restricted (by goop) at this very small throttle position.
The TPS would not match up what the other sensors are seeing.

Idle would still be good because its often bypassed the main butterfly anyway.
Its only at very low butterfly openings that there is any real airflow along the walls of an intake., but only in the very near vicinity of the butterlfy.

Normally most airflow is in the middle of the port.

But for this idea to work it would realy REALY have to be gooped up against the where the butterfly rests .

FYI, Mine were 175 - 180.

I understand the principle, I think, behind this tool. However, where I get lost is how you can keep all of the intake valves closed, so that the air pressure you are putting into the intake acutally comes out the leaking hose, instead of just going down the open valve.

I had a vacume leak which created a lot of symptoms similar to what you've described and I never could find it using carb cleaning spray. I finally just got dumb lucky, and found it because I was looking for something else, in a difficult spot, which finally allowed me to see the last 1/8 inch of the hose that had become disconnected. It looked like it was connected, from every other angle.

Your exactly rite , and thats where the whole idea falls into the poop.

Another way (the rite way) is to use a threaded adaptor to fit the spark plug hole and connected to an air compressor and presure gauge.

Its called a leak down tester.

https://www.xs11.com/tips/misc/leakdn2.gif

With it you can do very accurate asesments of valves and rings, cracked pistons , head gaskets , blown heads .., and also depending upon the cylinder its conected and the position of the valves it will show either intake or exhaust leaks.

Its a tool that gets used after every 1/4 mile pass on high powered drag cars to see if they should strip the engine down and rebuild it before the next run.

A real valuable tool.

the other day I finely replaced the gromet that fits in the oil seperator box on the back side of the engine that is part of the PCV system, the gromet that I replaced is part number 3 here https://www.hondaautomotiveparts.com/...EATHER+CHAMBER
after replacing this gromet with a new one my idle became more stable, and idles smoother at lower speeds, and the engine seems to be over all more happy, I was suprized at how hardened the gromet had become over time, creating not only a vaccum leak that I could not hear (you can hardly even see that part of the engine) but it was also alowing crank case gasses to escape.

VX hesitation problems at 1500-3000rpm
 

Just some info for VX owners. I just purchased a 92 VX and at 1/4 throttle, between 1500 to 3000 rpm it would sputter and hesitate. When it started to hesitate, if I gave it full throttle, it would clear up and accelerate, but trying to maintain a steady speed would be difficult.

I didn't get any check engine lights at all. The first mechanic replaced the Throttle Position Sensor. That didn't fix it so the Honda dealer looked at it. They replaced the ECU, and did conitinuity check on all wires and couldn't find the problem, so I brought it home.

I checked the TW sensor(temperature coolant sensor) and observed that it had 2.4K ohm resistance when cold, and when it got to operating temperature, it was 299 ohm. They symptoms above acted like it was running to lean. It would have difficulty starting when hot on a hot day, and had a very low idle. Either the O2 sensor is no longer calibrated and running to lean, or the TW sensor is out of range. I added 150 ohm resistance in series with the TW sensor, to bring hot temperature resistance to 450 ohms, and guess what? I no longer have hesitation, it starts easily when hot, has plenty of power. I tested it with 100 ohms, and still had hesitation, so 150 was right on, withtout throwing any engine codes.

Does anyone know what the TW sensor should read when the engine is at operating temperature??

I do have an oxygen sensor on order, an L1H1, and I will replace that anyway and see if that clears up the problem without the extra resistance, and I will post the results. I will also post the mileage with the resistor in place, since it may be running to rich.

Interesting news! Welcome to the site!

I've got a similar issue with the vx i just bought. It misses inbetween 1300-2700 at light throttle. a second after you get on the gas the engine feels like it changes modes and then pulls strongly and smoothly. I just put in the correct spark plugs (replaced the bosch with the ngk v-power), and hopefully that will solve the problem. I don't know enough about the engine coolant temp sensor to answer your Q. Hope you figure it out!

Getting a similar thing now with my 93 CA VX.... after I patched in a lean burn 49-state ECU and 5-wire O2. I can tell that it is going into lean burn, but then the injectors seem like they are randomly miss firing.... researching now.... thinking lean burn calibration of some sort.

Have you guys solved your hesitation issues from 1500-3k? Having similiar issues, no cel, new oem rotor/plugs/plug wires.

I think a slight hesitation or stumble is a pretty normal characteristic of lean burn. But it should be very slight, and it should only happen at low rpm, and with light throttle. If you set up a lean burn monitor it's easier to follow the pattern of when this is happening.

There's also a lot of very good troubleshooting info in this thread, so you should go through the basic things mentioned. Check the timing.

One thing not mentioned above is valve clearance. It's probably not causing your symptom, but it might be a good idea to do it anyway.

Also, is your car CA or Federal? I assume the latter. How old is your O2 sensor?

I don't know much about Honda's, but I had a simular problem on a Ford Escort and it was the idle speed control motor. I think I would replace all the vacuum lines anyway since it can be done for just a few dollars, there could be small cracks in them causing the engine to surge. If it is not your problem now at least you wouldn't likely have to worry about a vacuum leak again for several years.

Edit: I just read another forum about the same problem on a Honda surging between 1000-2000 rpm it was his throddle body gasket. Might want to check that.

Just replace the sensor. It's very common and very easy. That same sensor can be found at the junkyard across many Hondas and Acuras. Just make sure you replace the correct sensor as there is more than one coolant sensor.

Whenever I buy a 15 year old Honda or Acura (I'm on my fourth), I just swap out the motor for a low mileage JDM replacement. It's cheap insurance and pretty easy. When I do this I also replace all the hoses, water pump, thermostat, timing belt, accessory belts, and anything else that is hard to get to once the engine is in.

You can spend a lot of time and money chasing down a problem only to find it's a blown headgasket, worn piston rings, or burned valve. Most likely you just have a vacuum leak but what will you have 20,000 miles from now?

Alright, I just replaced my o2 with a used one and a brand new one. It
s still hesitating at 1500-2800rpm. Seems to be obvious lean burn is causing the hesitation? Any other ideas? valve adjustment?

I mentioned valve adjustment because I think it's a good idea in general. But I doubt that it's really your problem.

There's a lot you haven't told us about your car (unless I missed it somewhere). How long have you had it? How many miles on it? What year is it? CA or Federal?

How long has it been behaving this way?

There are probably some other questions to ask, but those are the ones that pop into my head right away.

Troy used to give me hell similar to what was described earlier in this thread. After having old gas in it, he wouldn't run worth a damn. You could be driving down the road just fine, then all the sudden it would stop getting gas, the RPMs would go all over the place, and sometimes it would sputter to a stall.

Replaced a dirty fuel filter. It didn't work. Then we cleaned out the fuel pump. That cleared it up for a couple of days. But then it did it again another day. Turns out the gas tank was rusting, and bits of rust were flowing into the fuel filter clogging it up, and keeping gas from getting to the engine.

After my dad swapped gas tanks from another Galant we had, it drove great and has never given me another problem since. All I've had to replace since that time was a leaky radiator hose.