thats right i just asked it. when my 92 rs with a 350 TBI/700r4 is warmed up and in park/neutrol idle is at 650-700. when in gear its down to 550. beening at 550 it kinda shakes a little, like the idle is to low. plus im told it should be a little higher, so imthinking 650-750 ish warmed up in drive. so i went to do that...car warmed up (temp going to 220 then cooling down to 190, repeat) so i put the ebrake on, put it in drive (like i was thought in mechinic class) and i take the cleaner off, losen the distruber and go to turn it one way, idle drops to 400. ok wrong way turn the other way, goes back to 550 keep turning...1/3 of a complete cirle turn later still at 550. turn a hair more and it suddenly just dies. ok turn distruber back a little put car in park starts right back up. all i have to say bout this is wtf? any help?

 

Im soory but your instructor is full of **** if he thought the class to adjust idle by moving the distrbutor.Ok by you moving the distributor you re messing with spark timing.You should not have done that an now you a digital timing light to set the base timing again.To set idle speed on a TBI it needs to be done with computer and a bin editor program.Basicly it needs to be adjusted in the ecm calibration.

 

exactly. You can set commanded idle in .bin to low value then use throttle stop screw to manually adjust. that is how I am running today.

your issue may be IAC. IAC places idle to that commanded in .bin. May be dirty and same on IAC passageway in intake.

 

ya that figures. and i know nothing of computers when it comes to cars...and this manual screw...thats on the throttle linkage by the carb right? bc i think ive seen that. and i think i adjusted my 88 mpfi that way to... good news is tho i now how to fix the spark timing with a timing gun lol, bad news is i have to find one.

 

TO SET YOUR IDLE ,GO TO THE LINK IN YOUR DASH AND JUMP A AND B WITH A PAPER CLIP,WAIT 30 SECONDS THEN DISCONNECT THE IAC .THEN START THE ENGINE IT WILL BE ROUGH,THE SET YOUR IDLE 500-650 ,TURN THE ENGINE OFF PULL OUT THE PAPER CLIP AND RECONNECT THE IAC !!!

 

My moving the distributor it will advance or retard globally at all rpm/map cells. The ECU has no knowledge of your changing initial timing. It is best to set it at factory specs per label under hood or FSM. Initial timing is set with ESC connector disconnected so that ECU does not move timing during process of setting it.