Idle problems after rebuild
Thread Starter
Intermediate
Joined: Jun 2007
Posts: 33
Likes: 0
From: Winnipeg Manitoba
Idle problems after rebuild
Hi Guys, my 1990 Auto has just been rebuilt and having trouble with idle, The specs are based on a ligenfelter grind with the following details: duration@50, 243 Intake, 251 exhaust, adv duration 294 intake, 302 exhaust, lift @ valve .560 intake, .565 exhaust, 1.5 rocker ratio, 1.75 spring height, 100lb springs, closet seat, lobe sep 110. all cylinders are .30 over.
PCM for less has done several burns for us but still no luck. It appaers that the vaccum may be the issue and causing problems with the map sensor. This motor is raunchy and we just cannot get the thing to idle at all. We are at the point of pulling the cam and going to something a little milder. any thoughts or suggestions would be a great help.
PCM for less has done several burns for us but still no luck. It appaers that the vaccum may be the issue and causing problems with the map sensor. This motor is raunchy and we just cannot get the thing to idle at all. We are at the point of pulling the cam and going to something a little milder. any thoughts or suggestions would be a great help.
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Reset the minimum air speed,IAC,and TPS..you may have to find a sweet spot to get it to run right.The factory settings may not be up to par.
For exmaple,if the factory is say 450 or 550 rpms at the TB,you may need to set it a little higher.
For exmaple,if the factory is say 450 or 550 rpms at the TB,you may need to set it a little higher.
Safety Car
Joined: Nov 2004
Posts: 4,991
Likes: 5
From: The Pines South Jersey
If the only problem you have is with idle - set the min idle about 25-50 rpm below the target idle for the ecm. you might even get to the point of disconnecting the iac altogether.
My cam isnt that nasty and mine idles at 1275 in park and neutral, 850 in gear
My cam isnt that nasty and mine idles at 1275 in park and neutral, 850 in gear
