Extremely weird idle issue..

[westerndevil]

okay so some back story.. Ive had my 98 gst spyder almost a full year now, and since i bought her, shes had a very weird idle issue i cant seem to figure out.. at cold start, it idles great at 800-900 rpm. when it heats up, it will start to surge and then after more driving, it goes back to normal.. but where it gets weird, is when i turn my car OFF and let it sit for a couple minutes, and go back and turn it ON, it will idle at 2500-3000 rpm and act as if i have my gas pedal depressed, almost like a sticking throttle cable. The TPS is new, i have an IAC block off on throttle body, the cable is NOT sticking. Ive ran out of things to check that i personally know of. Ive checked other threads and cant seem to find someone with the same problem...

FOR THOSE MENTIONING IDLE CONTROLER.. I HAVE IT BLOCKED OFF SO IT IS NOT THE ISSUE.

 

[Boostedwheels]

check for vacuum leaks. check all lines and the do a BLT. I have had a vacuum line disconnect on me and my car will idle funny. if I am correct (new to dsm) check the idle control motor. just a few things to check, good luck

 

[westerndevil]

check for vacuum leaks. check all lines and the do a BLT. I have had a vacuum line disconnect on me and my car will idle funny. if I am correct (new to dsm) check the idle control motor. just a few things to check, good luck

Ive checked for vac leak and have done a BLT.. id assume if i had either, it wouldnt cause such issue on after starting then re starting... thats why this is so weird to me.. only having real issues after i drive it, turn it off, then start it again.. oh and i have my IAC blocked off, so its not an idle controller issue..

 

[Boostedwheels]

check out the idle control motor mine has a little play in it and I think that's why my idle floats up and down often, take it out and see if it has a lot of slack when it twists, not sure if it matters just a thought.

 

[gst-turbo]

Check iac with a multimeter

 

[westerndevil]

check out the idle control motor mine has a little play in it and I think that's why my idle floats up and down often, take it out and see if it has a lot of slack when it twists, not sure if it matters just a thought.

I have it blocked off.. so that wouldnt be an issue. thankyou tho.

 

[91talonts1]

I've ran without an ISC before and could never get the car to idle consistently. It would idle right one day and then want to either choke out or surge badly the next. I went back to using an ISC and with it setup and adjusted properly the idle is much more consistent. YMMV.

 

[zedicus]

run with the ISC. best bet is to block the FIAV and iether block or make sure the EGR is working correctly. the EGR is good to leave active but i have had the valve go bad and cause random vacuum/boost leak that was hard to find.