High Idle..... I dont know
Thread Starter
Racer
Joined: Aug 2007
Posts: 305
Likes: 1
From: DRAYTON VALLEY ALBERTA
High Idle..... I dont know
I am trying to adjust the TPS and IAC. I am folowing the instrcutions off of Vader86's website. I have K.o.E.O and IAC plugged in with the connector in the diagnostic port for 30 sec. I unplug IAC and turn key off. Then I remove the conector. My throttle plate is completely closed on my FIRST Intake. When I first fire up after this it idles about 850RPM or so. But the second I give the throttle a shot, my idle goes to 1400RPM and stays there. I dont have any vac leaks that I can hear. And even if I did why would it start at 850 and then go up. 850 is still too high for my likings Id like to have it down at 700-750 Rpm
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
First off, with the IAC disconnected, you need to use the screw in the LH side of the TB to back down to base idle of 450RPM.
Since you idle jumps up you may have a plugged IAC pintel passage or a faulty IAC. You could remove the IAC motor, clean the pintel and its bore under the TB and try the adjustment again; if that fails replace the IAC.
The above assumes you have no vacuum leaks.
Since you idle jumps up you may have a plugged IAC pintel passage or a faulty IAC. You could remove the IAC motor, clean the pintel and its bore under the TB and try the adjustment again; if that fails replace the IAC.
The above assumes you have no vacuum leaks.
Thread Starter
Racer
Joined: Aug 2007
Posts: 305
Likes: 1
From: DRAYTON VALLEY ALBERTA
My screw is backed right off and the idle is still too high. So what you are saying is the IAC when plugged in to get the pintle to close fully, it didnt close up like it should have. This is not the standard twin blade throttle body this is the one on the FIRST intake. Because right now the IAC is unplugged and I cant get my idle anywhere near what I want. With timing conector un plugged I can get it to about 525 or so, but no lower. Then when I plug the timing conector back together the idle goes to about 900rpm or so and then the first rev it sits at about 1400. This is still while the IAC is unplugged. Is this normal maybe, should I not rev it. Will it fix itself when I plug the IAC back in. Also my voltmeter quit so I think my TPS is close, but if it is not will this have any bearing on it. Maybe I will get a new voltmeter and start again tomorrow.
Team Owner
Joined: Jan 2003
Posts: 20,322
Likes: 249
From: Summerland B.C. Canada
Get a new meter, TPS setting has to be close to spec, for a good idle.
It does sound like the IAC's pintle did not completely seat, are you sure it's working ?? Can you hear it or feel it working ??
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf
It does sound like the IAC's pintle did not completely seat, are you sure it's working ?? Can you hear it or feel it working ??
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf
Burning Brakes
Joined: Dec 2007
Posts: 1,068
Likes: 6
Get a new meter, TPS setting has to be close to spec, for a good idle.
It does sound like the IAC's pintle did not completely seat, are you sure it's working ?? Can you hear it or feel it working ??
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf
It does sound like the IAC's pintle did not completely seat, are you sure it's working ?? Can you hear it or feel it working ??
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
With the Pintle fully extended and the Butterfly completely closed, it won't run. Air is getting in from somewhere - either through the IAC passageway, the throttle shaft or there's a vacuum leak. When you ground the diagnostic link, you should hear the IAC motor chugging away as it extends the Pintle into it's bore. When it stops, disconnect it. If you can even get it to start, something of the above is going on. If not, turn the screw to get some air into it; then adjust the idle to 425 to 450 rpms. When done, plug the IAC back in. Reset TPS to .54 volts. Slightly depress the accelerator and start it. Let it run for 10 seconds. Off for 5 seconds. Restart and your Actual RPMS should be 50 +/- of Targeted on your scanner in Drive or 100 +/- Park/Neutral. Then note that RPM and turn it off and restart it. Restart should be higher than your noted #, but return to that # in 60 seconds. Then leave it alone. The only reason to adjust Minimum idle is with a new throttle body or if it's an '85 (wherein a Bulletin identified a stalling problem that was corrected with an increase in Minimum idle to 500 rpms). There is no way for it to get out of adjustment unless you monkey with it.
