Hey my friends..

I have a 91 z28 350 Tpi. It was original auto, but converted to world class t-5. I cannot get idle to go below 1300 rpm. I have replaced
Idle air control valve
TPS sensor
Distributor
Spark plugs
Brand new injectors (stock 22lbs)
Alternator

Anything to do with idle ive changed as well as made sure my timin is 6* BTDC.
Any ideas and also since its now a converted stick should my timing change to accomadate the high idle? My understanding is manuals idle around 850 rpm. Thanks guys

 

When you replaced the IAC, did you perform the minimum air setting procedure, where you punch out the cover on the throttle stop screw and adjust it with the IAC fully extended?

 

The ECM controls the idle, and it's higher for an automatic than a stick so a program change may be in order, also I do believe the timing is different for a manual than an automatic.

 

Not entirely correct; the automatic idles lower than a manual. Manual idle speed is around 750-800, automatic is 650-700. There's no good reason for the ECM to be holding the idle so high. Pretty sure the base timing is the same as well, or at least close enough to not make much difference.

Likely factors include incorrect minimum air setting, a vacuum leak, or a failed coolant temperature sensor.

 

What are you measuring the idle speed with?

 

I stand duly corrected on the timing.

 

Thanks everyone for the help! Okay so no i didnt set the minimum air speed, where is this ALDL port at ? Ive looked around the steering wheel and by the fuse box to no avail. Again its a 91 z28! Thanks everyone for the input

 

Ok so today i tried to set minimum air setting.. I connected ports A&B on the ALDL ( i think it was the ALDL not 100% sure
As ive never messed with it b4) i followed the steps and when i started the car with no IAC valve connected it steadily idle around 2000 RPM. I have the idle screw backed out all the way as well but still have high idle =[ i dont understand why it was idling at 2000rpm with no IAC valve, could this point to the real problem !?

 

Do you happen to know what the voltage is on your TPS? Should be around .59.

 

Jus wanted to update everyone on what has happened. Car passed smogged, apprently i had no high idle the RPM guage wasnt accurate. Did some research and it does happen to these tach's a lot so HEADS Up!! Also i didnt need any chip at all for my conversion (auto to manual) my car is pulling hard thru all gears ! YEEYEE !!!!!

 

You can't hear the difference between 700 and 1300 RPM on a V8?

 

Thats what she said