Hi, 95Z M6 here having some idle issues. When the car is just idling it jumps up and down in rpm pretty erraticly. Runs fine driving it just idles poorly. About 300 miles ago rebuilt the top half of the engine from blown headgasket. replaced water pump, opti, coil, plugs, wires, cap and rotor, o2 sensors, and had the heads resurfaced. All I can imagine is the IAC valve or valves not being adjusted properly??? Please help!

 

sorry I didn't include this in original post. Car is also running pretty rich. Only mods to car are k&n, Long tubes and true duals. Thanks

 

Do you have the means to check your IAC counts? You can clean these also. Try that and re-adjust your valves. Do you know what your MAP sensor is reading?

 

Also check your vacuum lines for any tears or anything you forgot to connect.

 

don't have the means to check iac counts. I will check my vacuum hoses hopefully this evening. Any idea how much a new iac costs and best place to get one?

 

Try and clean it first. If it breaks, no biggie because you're buying a new one anyways. Do you know anyone with a throttle body you could throw on your car? That at least would narrow it down. It only takes 5 min to pull the tb off.

 

Why do you feel its running rich? Under what conditions.... idle?..... part load/closed loop?..... WOT/PE mode?..... "all of the above"?

 

Whenever I crank the car and rev it up the black smoke stains the concrete under the exhaust pipe. also, just idling there is a moderate amount of gas smell. Exhuast pops some too, don't know if that's just because or if it is related to this.

 

I think that you almost have to hook it up to a scanner and read the sensors to find the problem. Do you have a labtop? There is freeware on the internet that would allow you to scan your car. You'd just need a cable. AKM sells them. I bought mine for like $45 from Mastach.com .

 

hey sweetred95ta what software are you using to scan? Freescan looks like it only supports 94 and older so what else is out there? And is there a cable to connect to the 95 OBD1 connection since it is the OBD2 style but OBD1?

 

Your 95 OBD-I PCM is identical to the 94 PCM.... FreeScan will work. So will TTS DataMaster which is also free for a limited number of uses. You just need the correct cable, because your 95 has an OBD-II ALDL connector under the dash.

DataMaster:
http://www.ttspowersystems.com/diagnostic.htm

Cables:
http://www.akmcables.com/

There's also a version of EFILive (V4) for OBD-I:
http://store.efilive.com/

 

Mastach.com has the cable with prongs on the end, so you can use it on the obd1 plug and the obd2 plug. I've had mine for a while now and never had any problems with it. Plus, it's cheaper than the other "molded" plugs. Freescan does work on a 95 and PCMComm also works and is free.

 

i would take some carb cleaner and check around the intake manifold and tb for vacuum leaks, sounds like the culprit to me.

 

sounds like a plan, will have to check that manifold..