this is not a "how to" ? but i'm not sure the end result is right... i set base timing with EST disconnected. reconnected it, cleared the code, and attempted to set min air. after the connector is removed and i attempt to set idle, engine will not come close to starting without a lot of throttle adjustment - then it throws the TPS way off. i'm barely at .54V now, but that was due to NOT setting idle speed with IAC disconnected... so in other words, if i set the idle high enough to run with what is supposedly minimum air, TPS will be too high. as it stands right now, i gave up on it, and let it sit where it was with base timing. and the final end result to all that, is that it also threw off the T/V adjustment, and the said procedures for that don't exactly work for my trans, as it is slightly modified. but i can get the builder to help me out with that, i'm sure. right now, i need to get the min air adjusted and be sure it's right, and TPS. thanks for any help...

KAM

 

That's why you do it in sequence.
When you're setting minimum air, you're adjusting the throttle blades to be just far enough open for the engine to idle. When its set, then you re-adjust the TPS.

 

roger that - when i set the idle, the TPS will NOT adjust to specs, as in .54V, +/-... it is about .6V or higher, which leads me to believe the min air is not right...

 

min air rate is set in "drive" about 550 rpm. I don't think TPS is adjustable????

 

it has very minimal adjustment to it. point is, once i acquire minimum air, when i check TPS voltage, it is beyond .54, like .6-.7. and i've heard of min air being set with EST connected and disconnected - so which is it???

 

Engine running normally, EST connected, IAC valve all the way closed, Automatic trans in drive, adjust throttle plate screw Idle RPM to 550. That would be the lowest RPM the engine will run in gear if the computer commands the IAC valve all the way closed. TPS voltage spec: under 1 Volt - not adjustable. What some people do is set the IAC count by adjusting the throttle plate screw in Park (to about 20 counts, above 50 counts is showing a problem). Not as acurate but.....will probably do in a pinch. My advice is to do it as I explained.

 

If you're working with a 90-92 the TPS is non-adjustable. End of story, don't worry about what it specs, because the ECM judges its position based off of its initial closed value. If you were using an earlier style sensor with the slots for adjustment, you could crank it either way and the ECM wouldn't know the difference.

 

cool - thanks for the replies...