Help! She doesnt want to run right... Stumped?

[97EclipseGSTer]

Hello DSM community.... I just got back from Europe after a few months visiting with my other side of the family... now I'm back to the dsm problem.... here it is

My car starts up and idles at 2K, then as it warms up, the idle seems fine at 1500K, then when it warms up, the idle is between 1k-1,400k... which is high. Well I played around with the Biss screw and replaced the o-ring. Didnt do anything. So I then checked my TPS and ISC and they are both fine. Well... then I noticed that when the car TRIES to normalize around 800, the Vac drops to about 10 (instead of around 19) and there is electrical noises comming from near/around the valve cover/spark plugs/PCV. AT this point, the car definatly sounds like its going to die down and some popping noises comming out of the exhaust. I did a boost leak check and there was no leaks. WTF

I think that electrical noise is the PCV for some idiotic reason... can someone PLEASE help me with this... I'll try to get a video and some sounds of it today. I've spent alot of time/money trying to fix this.


RYAN

 

[hereitcomes]

I have that same problem...but mine only does it occationally on start up, or randomly driving. My vac goes to 10 and it idles funny. I have a blow thru set up with a MAF and translator...so im not sure if it could be boost leak related...because major air leaks like that dont have that effect on my car because of the GM MAF. I havent checked the PCV valve or IAC control, so that might be a good place too look because our problems are simmilar. Good luck dude.

 

[somdturbo]

Make sure your plug wires are not arching at all. This will def make your car run like crap, try also adjusting the throttle cable after the car is warm. Make sure all battery connections are secure and not loose at all. u probably already tried these things but its the simple ones that get ya. What did u pressure test it to? Try switching out your maf, sounds like a similar problem to a bad maf my friend had.

 

[dave99gst]

leak test ?
injector plugs ?

as everyone else said .. spark.

 

[97EclipseGSTer]

"I did a boost leak check and there was no leaks"

- i did this at 20 psi then 30 psi, fell after a minute or so at 30
- I changed my plugs, they are 100 percent brand new. I put in the NGK 7's.
- when you mean arcing... like the wires are touching or overr lapping eachother? Because these plug wires are less than 6 months old. I did occasionally spill a small amount of oil on them though....

And here it is again, the car runs fine when it warms up at 1500K rpms, but it tries to normalize to around 800 and it just sounds like it wants to bog down, vac goes to 10-9 and the electrical noises start up (what I suspect to be PCV valve)

 

[kwaliph]

And here it is again, the car runs fine when it warms up at 1500K rpms, but it tries to normalize to around 800 and it just sounds like it wants to bog down, vac goes to 10-9 and the electrical noises start up (what I suspect to be PCV valve)

Well the PCV valve is a one way valve that is designed to help suck out the engine oil vapors produced by your moving valvetrain. Our engines produce alot of backpressure in the crankcase (not sure why but it's not uncommon), and the PCV valve is SUPPOSED to stop the backpressure from ever entering the valvecover. As a result of a failing PCV, the oilstick is known to pop-out of its oil check tube, and/or oil will either be injected to your intake tract or sprayed liberaly all over your enginebay if you have a valvecover filter thing (given you are in boost at some high rpm like mine everytime it decides to spray).
I hope this gives you a better idea of what the PCV is and/or does for your engine and that it is a mechanical valve (ball and spring) that is highly unlikely the source of your "electrical noises" (or the idle issue for that matter).

Good Luck
Erik

 

[97EclipseGSTer]

I know what a PCV valve does... I'm not a noob or close to it, but that i s seriously what i hear. When the car wants to bog down, there is a "electrical noise", almost like sparks jumping from one node to another, but its really the PCV valve opening and closing really fast. OLDMAN, the wiseman, told me older brother about this.... I believe it was timing... I'm seriously just going to take a video and sound and get someone to host it and show everyone....

-RYAN

 

[kwaliph]

I know what a PCV valve does... I'm not a noob or close to it, but that i s seriously what i hear. When the car wants to bog down, there is a "electrical noise", almost like sparks jumping from one node to another, but its really the PCV valve opening and closing really fast. OLDMAN, the wiseman, told me older brother about this.... I believe it was timing... I'm seriously just going to take a video and sound and get someone to host it and show everyone....

-RYAN

I was not calling you a noob. Simply trying to shed some light on the subect so you can come to your own conclusion.

Hmm. I'm pretty sure the PCV doesn't just open and close at a "searching" idle. Here is what I can recall off hand from last year; In order for the valve to close, the intake manifold would have to be presented with equal or more than atmospheric pressure. This means that in order for your theory to be correct, the IAC motor would have to allow enough air to equal that of the TB butterfly at WOT. I'm pretty sure that's not possible due to the lack of volume allowable by the IAC. Again, I'm no wiseman... yet

If you hear a definite "Electrical Arching" then I put my dineros on it being a bad plug wire.
Just today, the mechanic next door to my shop had a car come in with a similar problem (surging or "searching" idle). He heard the "electrical arching" sound and turnsout it was a bad plug wire that would arch on every other spark to that cylinder. New plug wires fixed the issue.

An easy way to test your wires for proper insulation is to ground a test light and touch each plug wire in a few different spots. If at any point the engine changes idle speed, then that wire you were touching at the time is bad.

 

[GTM]

Well the PCV valve is a one way valve that is designed to help suck out the engine oil vapors produced by your moving valvetrain. Our engines produce alot of backpressure in the crankcase (not sure why but it's not uncommon), and the PCV valve is SUPPOSED to stop the backpressure from ever entering the valvecover. As a result of a failing PCV, the oilstick is known to pop-out of its oil check tube, and/or oil will either be injected to your intake tract or sprayed liberaly all over your enginebay if you have a valvecover filter thing (given you are in boost at some high rpm like mine everytime it decides to spray).
I hope this gives you a better idea of what the PCV is and/or does for your engine and that it is a mechanical valve (ball and spring) that is highly unlikely the source of your "electrical noises" (or the idle issue for that matter).

Good Luck
Erik

A bunch of misinformation here.
PCV (positive crankcase ventilation) valve provides a dual function. Note the word crankcase not valve train which doesn't need ventilation. The crankcase and valve cover store gasoline vapors from the gas tank and engine blowby which then is reintroduce into the intake manifold to be burned again. The DSM doesn't produce any more back pressure than any other engine. Any turbo engine will have a higher back pressure when under boost for the intake is under pressure holding the PCV valve closed which prevents any flash fire (backfire in the intake manifold) from reaching the crankcase and possibly blowing the engine apart and or from loosing boost pressure. When the crankcase pressure has no place to go when boost is greater than crankcase pressure it will force the dipstick out along with a lot of oil as it vents to the atmosphere. Only when you come off boost will there be a rush of pressure which may carry some oil vapors with it but nothing significant. As with any car that gets worn there will be more blowby and thus more pressure in the crankcase. When the design cannot meet the need to vent, the dipstick will frequently be the easiest path though hoses can be blown off, seals blown out and gaskets to leak. I think you will find that most PCV valves do not use a check ball but a flat disk or plunger held closed by a very light spring.

......................
As for a clicking sound that would be a stretch if it's clean and in working order, it's nothing I've ever heard. Get a 3' piece of garden hose and stick one end to your ear and then probe for sounds to identify what you are hearing.

Cheers,
GTM

 

[97EclipseGSTer]

Could timing be an issue here?

 

[GTM]

Could timing be an issue here?

Yes. if it's too far advanced and the knock sensor is tying to compensate by retarding the timing. Under cold start the knock sensor may be deactivated though not sure if this is true with DSMs but this could account for reasonable fast idle when cold.

A leak in the crankcase PCV system can also contribute. Valve cover gasket, oil filler cap gasket, seals, oil pan, oil dipstick seal are possibilities. Possibly the charcoal canister, gas cap seal, and hoses.

Keep us posted.

Cheers,
GTM

 

[97EclipseGSTer]

well.. I know a leak in the PCV system can cause idle surge.. but this is like SERIOUS serge. I know its not the oil pan because I just redid the oil pan seal and nothing changed. I had a major oil leak problem after hitting a nasty pot hole... put a dent in it and a few bolts got loosened. I'm going to get some video and sounds of the car hopefully today and have someone host them... only thing is that the weather is kinda shitty right now.

The only things I can think of are these.... which I just need to test

1) Spark plug wires -- I'm going to put on a set of accel... which i heard seal pretty well... can you think of any other ones? I never had experience with them

2)Balance shaft t-belt.--- I bought the car with 79K and it has 90 now, the T-belt was supposably changed from the dealership, but you can never be too careful. I change the T-belt with a greddy one and I never changed the Tensioner or balance shaft belt... so timing can be off from this... but only thing is, doesnt sound like any bent valves... I need to do a leak down.. just scared to do it

3) Timming sliped from the pulley. The 2G's have the awful problem with pulley's splitting into 2... again, need to check timing

these are the only 3 things I can think of. I'm going to get a timing light today and have a friend check it, then I'll get back to everyone...

thanx for the help, if you think of anything else, let me know


EDIT: Well, I just remembered, if timing was off, then idle would never be fine. The car sometimes idles PERFECT, usually after I keep the throttle open a little so the car doesnt die!!! Then after I shut the car off and turn it back on, the idle turns to crap again... the same 1200K - 2K and it bogs down when it tries to normalize to 750-800.



-RYAN

 

[ReebisTSI]

Hey Paul, sorry to hijack, but i sent you an email regarding our little miscommunication. Your bro hasnt been online lately for me to give my address to. LMK if youi need anything.

Thanks for clearing this up.

Bob




Back on topic.....

 

[forumboarder154]

Ryan still wondering if your gonna show me pics of Injen Intake/BOV Type S just send pics to [email protected] or AIM me @ enjoisk8ter07.

-Kyle

Sorry for getting off topic...