disposablehero27

Ok. Well i will relay this coversation to them. Have them send me another tune. If the problem is not resolved with this last shot i will be going to another the very next day. Thanks for the help

disposablehero27

Ok, I came home and tried a few things. Some of what was a success.Cliffy i took your advice and bumped up the idle a touch. Now sitting at 1100 rmps....steady...and didn't stall once time, not even at the cold start. which is wonderful. I bumped up the psi a 1/2 turn with it, ran better but the fuel smell and exhaust burns your eyes. So i figued to rich. with down to a 1/4 turn, running lean still. So i said how about lets go 3/4 turn, seemed to run ok, but the longer i drove it, the more lean it wanted to stay with some bucking and kicking. I call it an ALL OR NOTHING pedal, if your not your pulling the car, increasing speed, its lean. so we are still back to square one, tune related, however simply adjusting the idle has fixed my stall problem, and idel problem it sits at high 14 low 15 occasion 16 at idle. the nuetral roll is 18.1 but jumps to 15 much quicker, in the beginning, and as i drove it, just leaner leaner leaner, more pedal more pedal, and i parked it.

I seem to find most of my problems at 2000rpm, and around it. simply HATES it. throws a fit 100% of the time.

cliffyk

How did you raise the idle speed, with your tuner?

disposablehero27

manually on the throttle body. I loosened the nut, moved the set screw out, retightened nut. Couldn't be happier with idle. Is this the part where you tell me, that was a bad idea, i'm stupid. haha.

cliffyk

Not stupid, however that is not an idle speed adjustment screw but rather the throttle plate stop screw.

What you did does raise the idle speed but only because it lets more air flow past the throttle plate, and in the process messes up the PCM's ability to control idle speed via the IAC valve. The idle speed is set in the tune.

The way it works is that there is some air flow past the plate when closed, but not enough for the engine to idle. The PCM then opens the IAC valve (about 40%) to pass additional air so the engine idles at the speed set in the tune. This is the procedure for the initial setup of the throttle stop screw.

As additional load is added (from the AC, generator, power steering pump) the PCM opens the IAC valve more to allow more air to flow through it and compensate for the added load. It also uses the IAC as an electronic dashpot when the throttle is closed on deceleration, and to control idle speed as engine and ambient air temperatures vary.

If the stop screw is holding the throttle plate too far open the PCM cannot perform any of these functions, cannot get the idle speed down to what is set in the tune, and becomes confused and unable to make sense of the idle air trim value stored in the KAM (Keep Alive Memory). That is why disconnecting the battery each time you adjust the stop screw, or change intake components or plumbing is necessary.

disposablehero27

alright. So next question. By doing this, it fixed 50% of my problems.... now what? haha. Should i adjust this back so I don't cause a problem in the tune and just relay, hey i tried this, and it got rid of stalling, falling rpms and gave me a steady idle?

cliffyk

Leave it as it is for now, however the real solution is to get it properly tuned including having the idle speed set in the tune as it should be...

disposablehero27

ok. will do. thanks again.

uberstang1

You had this car dyno tuned didn't you, which shop tuned it?

cliffyk

From his first post: