I know the procedure...but...what is the actual RPMs that the V6 cars are suppose to be set at? at 550 RPMs it seems as if the car doesn't even want to stay running...unless my tachometer is broken...(handheld unit). I am talking about after unplugging the IAC, warm engine in drive. I feel as though my idle is too low (it has been tinkered with). I've read 550, 450, 650 all over the forums...so which one is it?

 

I don't know about anyone else's but before I had fuel problems, mine ran between 600-700 once warmed up.

 

Perhaps this post will help:
https://www.thirdgen.org/forums/v6/2...rocedures.html

Idle speed RPMs listed there are from the GM service manual.

More specifically, that post contains the idle adjustment procedure adapted from Chilton's manual, tweaked to include removing the jumper between ALDL pins A & B before starting the engine (to avoid ECM damage as pointed out by Vader - additional info is linked in the post).

 

I have followed this guide...but it seems when I have my tachometer hooked up...I adjust it the idle to 500 RPMs it will hardly run. I am starting to believe it needs to be adjusted to 700RPMs in that procedure.

 

1. Warm the engine to closed loop temp (above 160*F, until the fan turns on and then off again).
2. Stop engine and put a wire in the ALDL as though you're pulling codes.
3. Turn key on but don't start engine.
4. Wait about 30 seconds and then disconnect IAC.
5. Turn key off, pull wire out of ALDL and start engine.
6. Use some sort of chock to keep the rear wheels from turning during the next step.
7. Set idle RPM to 650 RPM in DRIVE (NOT neutral).

650 RPM is per GM spec as in the TSB for "Cold Start, Sag, Hesitation, Stall". Spec for manuals is 550 RPM in neutral. IIRC, this TSB applies to 86 and 87 model cars with the automatic transmission. I don't have the TSB number on me at current.

 

That makes more sense, I'll try it out. 500 seems way too low.

 

When you're done, the hot idle, under ECM control, should be around 900 RPM in a Neutral (or Park, which is another Neutral with the parking pawl engaged) range, and 700 RPM in a Drive range. And should also be about 1200 cold until the ECM enters closed loop operation. Failing that, there is probably an issue either with vacuum leaks (most likely) or possibly MAF trouble (and yes, sensors fail without codes).

 

Well the MAF is about 6 months old and it idles just fine. I just know it has been tinkered with and want to set it back to like factory conditions. I just fixed that vac leak behind the heater controls but that didn't seem to even hurt the engine.

 

It is idling at 800 in park but again I need to drive it around to reset the IAC and ECM. Anyway, thanks to seafoam I found an exhaust leak on my passenger side manifold where the Y-pipe and and manifold come together. I did exactly what you specified put the OBD I tool in for a minute, removed IAC plug, turned car off removed EST, remove OBD. Started car, it was already warm; put it in DRIVE then set it at 650.


So in Drive it should be hopefully 700-650.