i have a 90 gxl and my idle is bouncy and shifter shakes like a ****. when i turn on the head lights my idle goes up 700-800 or when i blast the heat to full blast. when nothing is on car idle rough like 500-600 and sometimes 700. when i hold brake with nothing on it dips down and my idle is mostly bouncy. what can cause this? grounds? plugs and wires? any help would be appriciated.

thanks,
jon

 

how many miles on on the engine?

 

This has been covered at least 40 some odd times since I joined. Since the forums have started, im sure its been X100 of that.
SO im not trying to be a dick, I'll give you a few things that results in a jumpy idle, but for more information on them, just do a search within this section. Also READ the idle faq in the archive, its awesome.

Jumpy idle is the result of 'unmetered' air into the intake, and the ecu is trying to compensate for it, thus the up down idle. Its a fuel injected problem, as carbed engines will just have a high idle, so yes, technically it is electrical.

Jumpy idle is a leak of air, within the intake, it can be from a vacuum hose, a rubber grommet on the injector, a bad seal on the throttle body elbow, etc. Its ANY leak from the afm and on to the engine.
Check the following

-Idle Faq, read it and do it, you can find all parts at the dealer
-Timing, adjust it to spec
-TPS adjustment

Doing that will solve your problem and have your car running the way it was designed to, fast. You can do a search like I mentioned before on anything I mentioned and you'll find more than enough info including tutorials, websites, pictures, etc to help you. Good luck.

 

see.. my idle problem is this..

when i am at a stop.. if i take my foor off the brake.. it jumps up, then down.. and sometimes corrects itself for a second to get to 750 rpm...

i think its due to a shitty alternator.

 

Tell you guys what- adjust your idle using the FSM for your car, go step-by-step,and THEN if the idle is still screwed we can try to figure it out