car is intermiitently missing at idle

[charleyk]

New problem started. I've noticed a miss at idle that comes and goes. Idle speed, acceleration, gas milieage are all perfect but the miss can sometimes get pretty bad. With AC on, the miss is barely noticible. I've also noticed a pretty strong exhaust odor from paasenger side (so bad that can't have passenger window open at idle if someone's sitting there). I think I can hear a slight axhaust leak under passenger side but it's not terrible.

Any ideas?

86.5 NA

 

[AJ'S 88NA]

Have you checked your Cat?

 

[charleyk]

the smell is not sulfury or rotton eggs like so didn't think it would be the cat.

 

[turbo87targa]

Similar problem in my gte..... Dont know about the ac helpin (no ac D

but I have new plugs and wires (factory)
however I would consider my miss very noticeable. Acceleration and all is normal as OP said, but it sounds like 2 misses....one worse than the other.

In for the fix lol

 

[benchwarmer]

Have you guys tried the ignitor ground upgrade? My NA used to have a slight miss before I added that extra ground.

 

[charleyk]

not a slight miss. It's pretty bad at idle. Turbo87Targa, do you have the exhaust issue as well? Wondering if the missing might be related to exhaust leak.

 

[turbo87targa]

I don't believe my exhaust leaks, I have a ddp the dumps to atmosphere so it occasionally has an exhaust leak sound so if I had a small one I wouldn't notice, but it all just got put on with new gaskets so I doubt it's leaking.

 

[Koenigturbo]

Hijack: This is total guess: If he has an exhaust leak then couldn't it miss fire at the overlap stroke since both valves are open maybe the "Way" spark is firing when the overlap is happening. Although I think the way spark happens when the piston is at the bottom of the travel. I could be wrong,... a shot in the dark,...really dark.

 

[turbo87targa]

Dunno if it's related or not but I noticed today when I hit full boost (9 1/2ish) the ignition breaks up real bad....

 

[benchwarmer]

Dunno if it's related or not but I noticed today when I hit full boost (9 1/2ish) the ignition breaks up real bad....

What sparkplugs are you using?

 

[AJ'S 88NA]

And did you gap them before install^^

 

[charleyk]

I'n going to look into Koenigturbo's idea about the exhaust leak. It's too much of a coincidence that the miss and the exhaust leak started at the same time. Just took it in to body shop to have a new fender sprayed and I'll reply once I get it back and look closer. Thanks everyone.

 

[charleyk]

OK. I finally got the car back. I found that the first hose the connects right to the throttle body going to air cleaner is cracked. I'm thinking this could do it. Dealer wants $60 for it and thats nuts. Anyone have one for sale? or an idea where to get one? The part number is 17881-42030.

Thanks.

 

[cuel]

For the turbo guy: Search spark plug gap in the GTE section. Should bring up a ton of threads about making the gap smaller, although I believe most were running higher boost.

For the OP: Be sure all your plug wires are making good contact on both ends, and that there isn't any corrosion on the cap terminals, wire ends, or the tips of the spark plugs.

 

[EwGoetsch]

I had the same problem, ended up being burnt valves in my head. If you got the money and time take your head off and send it to the machine shop and have it pressure tested, cost me like $40 i think. but the shop owner is a personal friend of mine

 

[cuel]

I had the same problem, ended up being burnt valves in my head. If you got the money and time take your head off and send it to the machine shop and have it pressure tested, cost me like $40 i think. but the shop owner is a personal friend of mine

A compression test would be first.

 

[charleyk]

Are you saying that the leaky intake hose off throttle body to air cleaner and or exhaust leak cannot cause the problem? Just asking so I wont waste time and money chasing unrelated issue.

 

[cuel]

A vacuum leak will cause problems, and should be fixed. The exhaust leak can be an issue as well, depending on where it's located.


Edit: Do you mean one of the large rubber tubes between the intake and throttle body? That will most definitely be an issue, as it will let in a lot of unmetered air. You can either replace it OEM, or use some metal tubing and silicone couplers. There is a vac. line just after the AFM that goes down to the power steering idle up valve. Make sure you account for it if you decide to build/buy an intake.

 

[hornet7288]

I also have a miss at idle. I replaced wires, cap and rotor. It seemed to go away briefly once I replaced the cap and rotor but is back about a week later. I plan on cleaning the injectors and checking the timing. Some nights I will punch it and it seems like I can feel it lagging and other times it seems to be smooth. I would like to check compression also. It might be worth trying to do the ground rewire to see if that will help out at all.

 

[CRE]

I also have a miss at idle. I replaced wires, cap and rotor. It seemed to go away briefly once I replaced the cap and rotor but is back about a week later. I plan on cleaning the injectors and checking the timing. Some nights I will punch it and it seems like I can feel it lagging and other times it seems to be smooth. I would like to check compression also. It might be worth trying to do the ground rewire to see if that will help out at all.

Check for vacuum leaks, check the timing, check for oil around the spark plugs and wires check for error codes stored in the ECU and... what octane gas are you running?