Ok,

So I got this customer car at my shop and to be honest I am stumped ! It's a 87 300zx turbo 5spd...yadda yadda yadda. This car was heavily modified by an engine builder who built the engine for an estimated 500-550hp (give or take). When I first got the car use to start. It would idle BUT WOULD NOT RESPOND TO THROTTLE POSITION ACCELERATE OR REV NOTHING. So I cut the TPS connector and resodered them clean. found a vacum leak in the upper intake half along with some others. Replaced it and now the car wont start or ilde again and when you manage to start it she wont idle(I'm assuming fuel issue..pump..lack of fuel..etc..). There have been three sensors removed from the car along with alot other stock devices off the intake. According to the builder they where deamed "not needed". Which of course doesn't help me any because now that the car wont run it's a number of possible issues. However,there is a small leak in the neck of the tank fitting where they connect at the bottom. The neck is a little off and I belive that could be screwing with the pump but I don't see why it wouldn't atleast idle. I checked the maf and the TPS with an oem meter and both have good in conductivity. As for the car side, the wire harness is ok but some spots are questionable. Tommorow I'm pulling the computer out of my car(85 turbo 300zx) and sticking it in the 87 and see if it's that. I think the computer might not have been swapped out like it's surpose to before I got it. Even still outside of fuel I don't see the huge difference between the turbo and non-turbo computer (correct me if I'm wrong). As for fixing and repairing I'm 100% capable and quilified I'm just at a dead end here and could use some Z certified help....Anyhelp would be great !

~BB~

 

http://www.docs-auto.com/index.html

That's Doc, he should be able to help you if no one else here can... I know that my harness is shot, doubtful that the ECM is, but I broke off two screws from the filler neck when I dropped my tank, you can get the rubber ring seal at a hardware store, along with the same screws (they just won't have a phillips head indention anymore). Um.. Try AZ-Zbum. He runs a site is the forums basic Z31 Guru.

 

Thanks I'll pM him

 

Wow! Kinda hard to really diagnose with so many other things in the way.

Could be the ECU. Could be a fuel problem. Could be just about anything.

You don't really say what sensors are missing. You also don't really say what injectors are being used. But I'm guessing you don't know that.

This might be a time to have to invest in some good sensors for measuring air/fuel ratios.

You might want to consider talking to the shop that built the motor as they should have made it run before sending it away with the customer. I know if I just had a motor built, I'd be extremely pissed if the shop didn't make it run before leaving the shop.

 

yeah I ended up de-engineering the car I was givin to fix this car. When you remove the TPS and mass air and crank the throttlw like a 1/4 you get the exact same idle at the exact same RPM. The fuel neck screws are too big and the spring in the FPR are likely to be frozen.

 

UPDATE !!!!

I drove it today..barely..but I did..well kinda anyway. So I manage to rig up the throttle enough to keep it about 2k(looks like it's only running on three cylinders. ANd putted around the complex of Rogue Racing. She died a few buildeing back with the ground to the fuel pump hard wire wiggled loose. Other then that it's fine I suppose. So now I have to trackdown a short somewhere in the fuel pump circuit and do another compression test cause after she shut off from driving it I heard some odd when trying to re-start it. So I'm hoping it's nothing serious although now it wont fire more then likely the plugs are fouled all the way though. I'll keep you guys updated though.