General 1G REALLY high startup idle.

[English_Rugby]

When I start my 1g it goes straight up to 3500-4000 RPMs and acts really stupid. Took the ISC apart and manually adjusted to all the way closed - the car still does it regardless. Adjusted the BISS, still the same - also I did a boost leak test and there is a small one at the throttle body but it's nothing to worry about & wouldn't cause this. I just did a timing belt job and it started okay before then - could it be an issue with the timing?? I guess the way I see it it's either a bad ECU, bad timing or a massive boost leak I didn't find - it's got good fuel pressure. I'd just like some ideas please - it's been off the road too long and it's time to get her going strong again. Thanks in advance.

 

[jed344]

Does it stay at that rpm or drop down when it warms up? My car will idle to 2500-3000 rpm on cold start then within few minutes be down to 850 rpm witch is what i have ecm set at.

 

[English_Rugby]

I appreciate the point, but I'm not about to let my build warm up at 4000+ RPM any time soon at all.

 

[92AWDHX40]

http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html

this may help its not surge but related to idle, check your throttle body, and cable, isc, boost leaks something sounds stuck.

 

[English_Rugby]

Thanks, I had the throttle body apart to clean and also swapped over to a non-cruise throttle cable. I have heard the the coolant sensor in the t-stat housing can cause some issues like this? Appreciate the help from a fellow Michigander.

 

[English_Rugby]

Solved - thanks!

 

[curt-s]

..by doing?