keeslinger31

So I finished my lt4 hotcam swap and I ported the heads and installed thinner gaskets and got it retuned by pcmforless, It runs really great. I just can't get the idle sorted.

Problem: Will seemingly randomly die or idle extremely low at stop lights and sometimes idles high.
Right now I have the idle screw bumped open enough so that it won't die at stoplights but it idles really low like 400-500.
Attempted remedies: I have replaced the IAC to try and cure this issue with no resolve.
No vac leaks and new intake gaskets.
No codes.
Set throttle screw in just about every position and reset the iac everytime.

Doesn't seem to be too affected by temp because it will idle down as soon as I hit the bottom of the driveway when cold. But sometimes runs flawlessly
Ovaled out the tps sensor to read .67 volts
All the sensors are reading fine on my ethos with nothing out of the ordinary but its really hard to tell because it happens so quickly.
What I will see is the iac will try and compensate but it dies too quickly for it to correct it so it dies or it will close all the way and still idle abnormally high

It never did this before the cam.

I do have some knock counts that may be false seems like a high number?
Heard the map sensor may be at fault but looks to be reading normally
Usually the ICM when it goes the car will not start right?
It always starts right back up but you sometimes have to give it throttle and sometimes it will go back to normal idle after it dies?
It isn't missing. One of my o2 sensors is getting a bit lazy but still well within parameters.
Im genuinely stumped. And it has made the car no fun to drive not knowing whether it will die at the stoplight or idle really high.
My car may look nice but I find this extremely embarrassing!
Help appreciated thanks!

Here is a vid of it. Beware Earphone users the first revs are loud...It sounds awesome tho. Just won't idle consistently
http://youtu.be/fVrC4ZdG5Xo

89rs454

Got any codes? Sounds like the TPS to me.

POP6482

iTrader: (2)

I had a similar problem with my idle after finishing my LQ4 swap a few months ago. Wound up getting a new TPS and relocating my MAF closer to the throttle body. Seems to have solved the problem. Just watched you video, looks like you have the MAF in a good spot.

keeslinger31

No codes for the tps and it reads fine with no deadspots.

I take that as a compliment hehe. and ya the maf is as close as it gets really. It also reads fine.

is the iac closed at 0 or all the way open?
It seems to stick around there for some reason when it idles high so im assuming its open.
I just don't get why it would stick if its brand new and in a squeaky clean throttle body.
I just went and drove it and it seems I need to close the blades more and maybe that is my problem right now, but my secondary fan wasn't turning on for some reason and it is getting hot like 210 need to figure that out.
If it isn't one thing its another. as if I don't have enough problems to deal with...

Well i guess im crazy and the High speed fan doesn't come on till 225. Does anyone else think that is hot? Been working on bimmers too much.

keeslinger31

?

POP6482

iTrader: (2)

Did you try resetting your idle? Not sure if it is the same for the LT1 cars, but I had to unplug TPS, turn key to on position for 10 seconds, then plug tps back in. This will reset the TPS to 0. Let car run for a few minutes and then take for a drive. I have been told that it can take up to 200 miles for the pcm to relearn the idle.

cprmn14

iTrader: (3)

If its not TPIS, it sounds like a vacuum leak to me

POP6482

iTrader: (2)

Any updates on this issue?? Were you able to diagnose the problem??

keeslinger31

Unfortunately no

Lonnie P

What throttle body do you have?

I've seen some BBK's that had play in the throttle lever, which allowed random movement when returning to idle.

TTOP350

iTrader: (8)

Get it tuned locally. mail order tunes are just a close guess.

keeslinger31

It's a professional products 52mm it stays in one spot at idle.
I guess that's what I'm going to have to do

keeslinger31

I replaced the tps wires and it seems to be doing better haven't gone for a drive yet but the idle stays at 1000 on the tach.

keeslinger31

New tps wires didn't fix it. I have tinkered with the tps and throttle screw for hours to no avail. When set correctly it dies and when adjusted so it won't die it idles normal and the revs hang alot.

I am at a loss, the car has been sitting in the corner for a long time now
I don't know what to do to it. Been driving my new car (06 Gto)
But I miss the camaro. What should I do?

Review. Car dies at idle. Tried adjusting the stop screw no dice.
Replaced iac still no dice. Adjusted the tps and the iac to the right numbers via scanner. Still dies. Thinking about getting a storage unit and just hiding it from myself for a couple decades maybe then it will decide to function properly.

Anyone have this problem?

keeslinger31

replaced the clutch as it started slipping due to a oil leak.

Going to get it dyno tuned in hopes of fixing the idle.

keeslinger31

still haven't figured it out.

Replaced IAC and tps and tried adjusting it
I either get it to idle really high like 1200 and then about 700 at random
Or it idles a little high at about 1000 or at 500 and barely running which is where i currently have it to keep it from dying at stop lights or anywhere else

It's obviously an intermittent issue but what would cause it to idle down like that
It has to be losing air or fuel or spark but not completely or dropping compression on a cylinder or a sticky valve? Loading up with fuel?


I just got new motor mounts in so I fixed my shake but it still tries to die even just backing out of the garage then letting it idle it will idle down to about 500 then go back to normal

The more I think the more it seems like it's loading up on fuel

I usually have to rev it to keep it alive if it does idle down or it will die eventually but sometimes it idles back up on its own
It won't idle normally without the iac being too high It's like 70 and it idles too high still (i'm guessing to compensate for the rich condition)
then it can't open enough to keep it running when it loads up?

When this happens I can see the iac counts max out and rpms drop so something like a stuck injector or intermittent vacuum leak?


Guess i better start over

mmadden55

Clean your electrical connections, at the plug and at the pcm and all between,if that doesn't do it, then check the wires for intermittant break.

tnitz8787

If it's lean at idle, the rpms will hang and then come down to where ever it idles at. If it's rich, the rpms will drop down lower and then come up to where it idles. I don't know if that will help you any, but that's usually where I start when assessing idle issues.

keeslinger31

Drove it tonight Motor mounts are excellent but it idles too low at almost every stop.
Sometimes it idles back up to 900 sometimes it just chugs at 500rpm and the idle will fluctuate up and down as well other wise seems to run good
need to get a scanner on it and see whats acting up