Hi all!

i have the problem, that my idle isnt under control properly...

checked with datamaster today, i have the following:

engine cold: IAC Pos 160, IAC Min 70
engine hot: IAC Pos 80, IAC Min 70

commanded idle hot 800rpm....

i tried to reset the IAC the following way:

i shorted pin A&B of the ALDL

switched ignition "on"

disconnected the IAC

switched ign. off

removed the bridge from ALDL

started the car and setted idle with stop screw to about 750-800rpm

switched car off

disconnected battery to clear ecm

connected IAC and started again...

and guess what..rpms are at 1200, and IAC counts are at 160.....

now what?

does it only work in closed loop?

did i make something wrong?

thanks for any opinion....

 

You did everything correct except for one thing....;

.... you should have set the idle w/the stop screw to 450-RPM.

 

sorry, forgot to mention some information..

engine is a 396 with 195cc AFR heads and an XFI 467 cam (230/236 113 LSA)....

i will check again tomorrow, maybe i find sth out.

thank you

 

Are you waiting about 30 seconds before you disconnect the IAC (should be all the way out by then)? I'll assume that you have a prom calibrated for your setup.

 

There is a good possibility that you need to drive the car for the IAC to settle into an idle mode. Many GM mask's require a MPH of greater then 35 to do an IAC reset and learn.

Although I really don't know if $8D is one of them.

The other thing to to check that the ECM is in "idle mode." This is 0 MPH and the TPS% below a threshold. Otherwise the ECM will think that the car is moving or the go-pedal is being pushed.

RBob.

 

hi all, and thank you for your statements!


@84KYSS

yes did wait, i also veryfied function yesterday, removed IAC and housing, and put some grease on the pintle, shorted Pin A&B , switched on, and got a nice ring of grease on seat of the pintle..so IAC Motor itself is working! i have a prom calibrated for the setup, the tune gets real close now!


@Rbob

yes, ECM was in idle mode, according to my calibration, it needs less the 2.3% throttle, and less than 14.1 mph, also idle bit in datamster was 1 (idle)

the other thing you mentioned....i dindt drive the car, so i tried setting the idle, have taken some logs and put it in the garage..so, thats pretty possible, that i just need to drive the car, and see what happens!

i will let you know, whats going on..

i will sett idle once more, and then drive it...



Reinhold

 

Hi all!

i drove the car, and..the IAC counts go down to about 15....and i have a nice idle @800rpm (hot)

when i start the car (cold), its idling at about 1000 rpm (160 IAC counts, commanded open loop idle speed)..

When i start car hot, its starting at 1000rpm (130 IAC counts) and then goes down within 30 seconds to about 800rpm (15-20 IAC counts)

seems that is normal...

greetings

Reinhold