2G Loud crackling noise from injector area and low/rough idle

[SKOOOOJE]

I've hunted through the forums and still can't figure this out. I've been trying to figure this problem out since I bought the car and I just haven't been able to figure it out. The car idles low and rough, then smooths out for a few seconds and goes back down. There's also a really loud crackling noise from around the injectors that goes away once the idle smooths out. I suspect that it is spark leak but I can't see any visible arcs at night. It also sounds like there is a pretty decent misfire when the idle drops. I have no boost leaks or vaccum leaks. I recently replaced the injectors with 550cc injectors as well as installed a walbro 255 and a fuel lab afpr. I have also replaced the plugs and wires with NGKs, as well as replaced the idle air control valve. I also cleaned my throttle body today and it helped with the idle issue a little bit but not much.

 

[We're on Boost]

I suspect that it is spark leak but I can't see any visible arcs at night.

Check this out (starting at 23:11):

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In fact watch the whole video because it's really good, and he checks on some other things that could have been it.
Catch the parts where he checks each exhaust runner with an infrared temp gun to find out which one is misfiring (running cool) which there was one but it wasn't making the noise.
He finds what was making his loud clicky noise at 24:33.

 

[SKOOOOJE]

Thanks, ill watch through this while I'm at work today and I'll update if it helps fix anything or not

 

[SKOOOOJE]

Check this out (starting at 23:11):

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In fact watch the whole video because it's really good, and he checks on some other things that could have been it.
Catch the parts where he checks each exhaust runner with an infrared temp gun to find out which one is misfiring (running cool) which there was one but it wasn't making the noise.
He finds what was making his loud clicky noise at 24:33.

I have a couple problems with that video, one my noise is different, and 2 I have brand new plugs and newer injectors. It has made the noise since I bought the car and also has always had the misfire.

 

[We're on Boost]

I have a couple problems with that video, one my noise is different, and 2 I have brand new plugs and newer injectors. It has made the noise since I bought the car and also has always had the misfire.

Probably should try to shoot some video with sound and post it. Some video when it's making the noise and some when it's not.

 

[SKOOOOJE]

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Here's a video of it, in the video it crackles when the idle bogs down but when I give it some gas it stops

 

[We're on Boost]

When it's idling slow I hear some thumping, like you might get when the idle speed is too low. Like the engine is stumbling and close to dying.
The little bit of crackle sound I hear is pretty faint and it's kind of like our "normal" valve train noise.
On the thumping, what is your idle rpm when it's doing that?
Wonder if you have a bad motor mount somewhere?

 

[chrysler kid]

Is there oil in your engine? When is the last time you checked the dip stick

 

[Lui-Kang]

I had a similar sound on my 1g. My PCV valve was leaking and would "flutter" open and closed, causing a vacuum leak and irratic idle.

 

[SKOOOOJE]

When it's idling slow I hear some thumping, like you might get when the idle speed is too low. Like the engine is stumbling and close to dying.
The little bit of crackle sound I hear is pretty faint and it's kind of like our "normal" valve train noise.
On the thumping, what is your idle rpm when it's doing that?
Wonder if you have a bad motor mount somewhere?

The drivers side motor mount is on its last leg, just haven't got around to replacing it

 

[SKOOOOJE]

I had a similar sound on my 1g. My PCV valve was leaking and would "flutter" open and closed, causing a vacuum leak and irratic idle.

I got a new pcv valve on the way

 

[mcrowell5710]

if you plan on getting larger turbo and/or increasing boost, lots of folks do a PCV delete and add a catch can. I can't personally confirm it, but i have read that a PCV won't open under boost. This doesn't make much sense to me since a PCV is essentially just a check valve....did you ever find your issue?

 

[steve]

The PCV is a measured intake leak under vacuum and must seal under boost. The problem is there aren't any new cars that use this existing value under pressure so most don't seal properly anymore.

The rocker cover vent allows any crankcase pressure to vent under boost back the the turbo inlet and acts as a fresh air supply under vacuum.

 

[SKOOOOJE]

if you plan on getting larger turbo and/or increasing boost, lots of folks do a PCV delete and add a catch can. I can't personally confirm it, but i have read that a PCV won't open under boost. This doesn't make much sense to me since a PCV is essentially just a check valve....did you ever find your issue?

No issue confirmed yet, my BISS screw is all the way screwed down and almost the entire head of the screw is broken. Got a new screw on the way and gonna put a new one in to see if that's the issue. If not then I had someone tell me to try adjusting or replacing the TPS so I'll do that if the BISS screw isn't the problem.

 

[SKOOOOJE]

The PCV is a measured intake leak under vacuum and must seal under boost. The problem is there aren't any new cars that use this existing value under pressure so most don't seal properly anymore.

The rocker cover vent allows any crankcase pressure to vent under boost back the the turbo inlet and acts as a fresh air supply under vacuum.

Just got a new pcv valve in today, it was 4 dollars so I figured may as well rule it out

 

[steve]

Test it with boost pressure to make sure it doesn't leak from the threaded end to the nipple end. If it does you can't use it as is.

 

[SKOOOOJE]

Biss screw fixed the idle issue, but I still have another issue. I'm gonna start a new thread for it but I also have a large lack of power when giving the car alot of throttle, it revs normally when going easy on the gas but if I try to floor it is bogs down hard