i have an 87 T2 87k miles with intake and cat replaced with straightpipe. i have a blown turbine so the exhaust smokes when i get on the boost. i just hooked up my air/fuel gauge the other night, and its stuck right in the middle and doesnt move. the car idles a little rough and when i push in the clutch to let it go back down to idle while driving, it feels like the car is about to die, but idle catches at the last second and barely keeps it alive. it feels kind of like the engine is idling in an "on/off" sort of way if you know what im saying. its not a steady idle, instead it feels like its about to die then the rpms just up and down from about 300-800 rpms. my question is what could be causing this problem? i was thinking it could be my o2 sensor (that would explain why my a/f gauge isnt moving) and its not the throttle position sensor because the check engine light isnt coming on... any help would be appreciated. thanks guys -jacob

 

TPS misadjusted will not give a check light. Go with that, then get back to us.

 

I dont think that the O2 sensor would cause that, but I may be wrong. Like rico said re-adjust the TPS and see whats up then.

 

Idling problems always start w/ the TPS. Really, do that first. I had a BADLY adjusted one till I got sick of the crappy and surging idle, so I adjusted it. Easy fix.

 

Same as the above. The 87 has no check engine light. The 02sensor is not in the loop at idle, so count that out. A lot of problems come from the turbo inlet duct being cracked at the turbo. Take it off and look where the clamp goes on the duct. Another source of air leaks is the hose at the bac. Spray some starter fluid on the ducts and vac hose to detect a air leak. Rpm will change if there is one. Another source of stumbling idle is the grommets on the injectors being old and cracking letting air in. Downloading the free factory service manual at http://fc3s.org and setting the idle per the manual i.e. the Fuel section will help you. The variable resistor being too lean on a 87 will give you a sad idle. The timing should be set with a timing light per the above mentioned fsm. Decent LEAD plugs might help some along with good fuel injectors. Setting the tps is a piece of cake. About five or six different methods. See the Search engine at the top of the page for tps setting.

I favor spraying with starter fluid on the vac hose and connections for finding a air leak quickly. Do not spray for any length of time directly into the inlet.

Read and understand this article: http://www.teamfc3s.org/info/articles/idle.html

 

i think the jackass that i bought my car from adjusted the timing. im sure that would make it idle a little bit rough. how do i change it? the haynes manual seems pretty complicated