I have just bought a 1988 z31 NA 2+2 5 speed. When I bought it the car would not idle and would run rough until it warmed up. I then replaced the spark plugs and saw 4 out of 6 were wet, reset the ecu and she ran good for about 50 miles and then it just would start running rich and blowing so much unburned fuel out of the back. It is fine if I reset the ecu for a bit then just wont idle. I can get above 2000 RPM and will respond fine at WOT but is just running rough hesitating on acceleration. I had the recall service done to see if maybe it was injectors but they did the work and reset the ecu and was just fine for a bit. They wouldnt tell me whats wrong when I brought it back to them "ECT" sensor is what they said lol. I have an 87 NA auto parts car with everything except the crank angle sensor. I just need to know where to look.

 

Welcome to ZDriver!

The first / easiest thing to do is pull the ecu codes (Which you erase everytime you pull the power).

Also check your CHTS.

 

Ok I will do that when i get home....I just hope its an accurate reading the previous owner jerry rigged a lot of the wiring Just as a reference will the ecu out of my 87 auto interchange with my 88 5 speed I believe my 87 does have the Wseries motor.

 

Well couldn't test the 88 last night my room mates 85 decided to pop a transister on the ECU and I had to pop my 87's ECU in it. A few months prior it was poping fuses on the fuel pump, roomie just decided to put a bigger fuse in. Could it be the relay causing the issue? I don't want to burn up my only verified good computer.

 

I fixed the issue the vacuum line for the AIV off the MAF sensor was broken pulled the electrical plug out of the MAF sensor and it idled perfect. Going to block off the vacuum line on the intake and remove the AIV. If anyone wants the writeup on how to do this here is the link: Robo. Will make your engine bay look cleaner and well less vacuum lines to replace.

 

Replaced the vacuum lines and MAF and sill ran wrong. Replaced the IACV and adjusted the Throttle Position Sensor. Now she is running perfect, and with no AIV and shorter intake she has a little more pep Also discovered if you break the Vacuum hose for the IACV good luck finding it, I just plugged in where the AIVs line was because I could not prevent my replacement lines from kinking. If you dont have to worry about emissions inspections you can take off the AIV and instead of searching for a $35.00 hose you can grab $3.00 worth of heater hose and a few clanps and make the fix yourself.