Paid SVOboy a visit!
 

So Wombosi and I drove out to Dartmouth college where SVOboy did some werk on meh car. 175 miles each way all interstate. SVOboy cleaned the IACV and replaced the PCV and diagnosed a vacuum leak. And cleaned the EGR a little, although we weren't able to get it off the hegemony because the bolts were too tight. Needed to have soaked the bolts in PB blaster for 24 hours or so. SVOboy also diagnosed the VSS problem and the headlights, which both seem to be electrical doohickey nonsense, although the driver side headlight is blown and the passenger side has a phantom electrical problem. The speedo/odomoter problem doesn't seem like it will be fixed from a new VSS. Thanks again for all the help Benjo!

I made a post in General FE if you want to read about the overall FE of the tank and the speeds and all that.

Congrats! So what was causing the vacuum leak, a cracked hose?

I couldn't figure out the source of the vacuum leak. The pcv valve was completely shot, so we replaced it, but it wasn't just that...there's still a pretty sizable leak somewhere. I blocked the iacv flow and tried closing off every hose but I couldn't find the leak at all. A bit troublesome...

was the iacv ever taken off?? what about fitv?

ive never seen a problem with the iacv, but the fitv goes bad much more readily.

I do not think the cv/vx has a fitv. Mine doesn't and I didn't see one.

The idle behavior hasn't changed since yesterday. Bringing it to the mechanic tomorrow morning. What are the things I'm telling him again SVOboy?

I put in new head lights. Passenger side works, but driver side doesn't. "Phantom" electrical problem on that side we think.
Vacuum leak maybe causing the roaming idle/surging idle/sticking idle.
Still need to fix the speedo/odometer. I think that's it! Everything else with the car is behaving well enough to not be bothered by. I had the rust fixed. The power lag/power surge is virtually gone, and I still haven't put in new o2 sensor. The low rpm jingle came back for another two seconds today but hasn't happened again....

The right rear brake is clicking really bad now. No idea what is going on there. Might have the mechanic take a look.

Thanks again SVOboy for the help

just saw the mechanic. he was working overtime or something! 9pm and he was at his shop. Told him about my trip to Dartmouth and the vacuum leak and how SVOboy checked the hoses and about the little rubber thing he replaced and the pcv valve replacement and yada yada yada. And about the headlight and the "phantom" electrical problem on the driver side low beam.

He said something that I found rather interesting. Car will not pass emissions with a roaming idle!! Is this true!? Seems outrageous. So hopefully he'll fix the roaming idle and the head light. My car will be in tip top shape then. Would be sooo nice to have the idle chum at 500, barely audible like it should be.

Mine passed, dunno about MA laws though. Did he say anything about the actual issues?

he said it could take 1 hour to isolate the electrical problem or six days. He didn't really say anything at all about the issues. But he jotted them down in a notebook. I'm very curious if not anxious about what he has to tell me when I see him tomorrow afternoon.

The electrical problem should be really easy, since we know it's the plug that is ****ed up...

the plug that the bulb plugs into? I didn't tell him that. I could swing by on the way to school or give him a call. What should I say specifically?

Just say that power for the low beams is getting to the bulb plug, so the problem is in the plug and not the switch, it is prolly just that the plug needs to be replaced. Also that it momentarily worked when being fiddled with. Prolly a lose contact or some corrosion or something.

cool, thanks. :)

On my VX, the one headlight plug was melted, and after looking for another in the junkyard for a while, I came to realize that this is a common problem for the 92-95 civics. I ended up just cleaning up the contacts, bending the "prongs" on the bulb, and the headlight has been working ever since.

When you were looking for the vacume leak, you said you plugged the IACV off. Did you plug it off, on the intake, where it mounts, or did you plug the hose coming off of the air filter?

When I was chasing down the wandering idle it ended up being that the valve itself had something broken in the seat arrangement. The valve looked OK, actuated OK, and seemed to me like it was Ok. However, somewhere it was leaking air. I finally plugged off the hose from the intake and then it settled right down.

I put my hand inside the throttle body and stopped the air flow there... I don't think the iacv it busted, because air is definately getting in somewhere else...

Well, the headlight ended up being a blown fuse-- so it's fixed. I stopped by at 1pm to see how the mechanic was doing. He hasn't figured out the idle problem yet, tho.

Haha, I prolly fixed the connection and then blew the fuse...shoulda checked it...:)

I seem to remember a member on here that said the source of his vacuum leak was a worn out grommet on the black reservoir box that the PCV system drains back into the backside (firewall side) of the block:
https://www.slhondaparts.com/images/PCI/13S020/022/4.jpg
Part #2

I think I checked that one...

ok, good. The things I can think of that would cause a vacuum leak:

1. intake manifold gasket (if the manifold has ever been taken off)
2. Fuel pressure regulator and the line running to it
3. Charcoal canister solenoid and line
4. EGR control (black box) system
5. EGR line/diaphram
6. IACV
7. Throttlebody gasket (if TB was ever removed)
8. PCV system
9. Incorrect aftermarket gas cap installed or OEM gas cap not turned until it clicks

Those are the things I can think of off the top of my head. I know you probably checked all of those though. Just kind of thinking out loud.

I didn't think of the gas cap, I checked everything else, and neither the tb or im seemed to have ever been removed. I was rather perplexed.

Yeah, the gas cap can actually cause a vacuum leak through the vapor system being active. It's just that the OBDI computers aren't quite good at catching that as the OBDII ones are.

But yes, very perplexing that the vacuum leak exists still. But according to Holmes, if all other possibilities have been removed, then the remaining, no matter how ridiculous, must be true.

So maybe the ECU is at fault?? unless we are both just missing something so obvious that we should slap ourselves in the head.

I'm fairly sure it is a physical leak based on several symptoms including the revs not dropping quickly. I plugged every physical hole I could and the engine still ran, the air must have been coming from somewhere.

Also, when replacing the pcv valve, it ran properly for about 5 minutes and then went back into it's old habits, which further confused me...

*sigh*

ok, two more things I just thought of

• Was the hose from the intake manifold to teh PCV valve collapsing?
• Was the throttle plate stop screw messed with at all? The little set screw under the throttle body stop tab.

It wasn't collapsing, seemed in good condition. Pinching it would mess drop the idle though, which is how I diagnosed the PCV valve (also took it out and blew on it).

The mechanic said the idle screw was messed with, but to me it didn't look like it. However, it is possible it was and the plate was being held slightly open, which would make sense...a lot of air was getting in...

Sorry, fell asleep. hehe. Took an impromptu nap. So, yeah, there was a very happy but very brief time when the engine idled at 500rpm. Was a thing of beauty. But then it went back to roaming and random. All the mechanic said was that the "throttle body was tampered with" and I think he pointed to the coil when you push that thing down to give it throttle. But maybe the screw--I don't know heads or tails when it comes to cars. Will be going to the mechanic in a few minutes to find out if all ended well!! Hopefully he won't be still scratching his head when I get there and will have figured something out. Thanks guys for batting this one back and forth.

Mechanic thinks there are no vacuum leaks. Umm... it just occurred to me if he's been looking for the last two hours and not found anything, I owe him $120 for nuttin?

That's why I've never taken my car to a mechanic, :p

nothing=nothing...I say you buy him lunch and call it even...

he wants to continue working on it tomorrow. I dunno, maybe it's not worth it!? What to do? Try to get it to pass inspection with the roaming/surging/pooping idle?

It's up to you, meng. I would call the DMV and ask them about the idle and see what they say. I don't think the car is acting funky, it's just a bit pulsy...I would want to check out the throttle wheel stop screw though.

I'd do a couple of things. I wouldn't spend any more money on this mechanic.

I don't know how much the idle is varying, but for the price of the mechanic, you may as well get it tested, just to see what is what. Maybe it will pass and you won't have any further problems. If it doesn't, at least you will have some idea what the smog guys have an issue with.

On the idle, you had one post which said that it stabilized for a short period of time, at 500, right? On my wagon, it would idle sort of steady, until the engine began to warm up a little bit. Then it would go into it's hunt cycle. Mine ended up being a bad IACV valve. The clue is it should not allow any air to pass through it, when it is off, disconnected from the ecu.

I would either pull it off and recheck it, or for the price, go to a pick your own part and pull one off, check it out, pay the few bucks, put it on, in replacement and see where your at.

I went back to doing almost all of the work on my cars because:
A. I can't really afford to pay someone else to work on them.
B. It seemed like almost every time I had someone else work on them, they would end up having issues which were either the problem I had paid to fix or something else which was induced by the mechanic. In either case, I almost always only got it finally fixed, by fixing it myself and if it takes 3-4 times for me to figure out what the problem is, then I just figure that is the cost of learning, to me. However, when I'm done, I at least have a clue as to what I did or did not do and what or what might not be the consequences.

Best of luck to you.

p.s. I do have a mechanic I use, when I get down and desperate, but he is a very experienced, very methodical mechanic and very much an exception.

Gary... My idle is exactly as you describe!
 

Mine likes to hunt after its warm too. I just had the IACV off and cleaned it. As it happens, I blew into it to see if there was any more cleaner trapped and I did notice some blow-by (and a horrible carb cleaner taste too!). So if I understand you correctly there should be NO air blowing through, is this correct? I'm not sure which hole I was blowing in, does it matter? I've been trying to track down this air leak and this is starting to make sense. Then again it could very well be something I'm overlooking. I'm going to go through TomO's list and see if there are any more culprits lurking. If you get a chance, let me know about the air leak in the IACV. Thanks!

https://www.hondiscountparts.com/imag...dard/AC188.jpg
blow into either of the holes that has a screen on it or the one that you can see the screw threads in.

The two nipples have coolant that runs through them. To help the iacv know if the car is warming up or not.

Yes, their should be no air flow, either direction on the two holes that attach to the intake manifold. Mine seemed like it wasn't leaking, that bad, but it should not be leaking, at all.

Well gentlemen, good news! He continued working on the car. He took the throttle body apart and cleaned it and viola, the idle is no longer sticking! It still is idling high but not roaming anymore. He said it might improve once all the stuff he sprayed in the throttle body has burnt off. And he said he'll do an adjustment in a few days.

I passed inspection with flying colors. I believe the co2 was 5.28 out of 20. Guy said o2 sensor is good! more lata, I gots to go.

Congrats on getting a stable idle and passing inspection! :D

When this is all said and done, you'll have to tally up what you've spent and let us see. :thumbup:

What was your NOx score?

so seafoam would have saved the day....