hello everyone! I have recently purchased z32 from an elderly gentleman in Florida.I purchased it with 116k miles on the original engine.it is a 1991 model twin turbo with a corroded wing and some old school Oz mitto wheels. I fell in love with the car and proceeded to purchase it. I then drove four hours back to my place is in Louisiana.that next weekend I took it to a friend's garage to show it off. We then went for a test run and he learned that the power was not all there.he brought it into the garage to begin to look at what the problem might be. we discovered that the coil pack connectors were dried out and cracked. I replaced all of them with brand new connectors.after replacing them we found out that one cylinder was still not firing. we then proceeded to look at a fueling issue.come to find out that one injector on cylinder bank number one was not working. I replaced all 6 injectors with new style injectors. I then try to start her up. She started right up and I let her idle for about 15 minutes. then the car stopped and it would not start again. Come to find out 1 of my grounds on the back of the plunum was loose. I read that when that happens the PTU can burn up and fail. I noticed the my CEL would not illuminate when I would put the key in the on position before startup. what does this mean? I also checked the relays and fuses and all were good. any help with this issue will be greatly appreciated.

 

I have never heard the one if the plenum ground is loose your ECU could fry, not sure that would be possible, a bad ground isn't going to cause a voltage spike at the ECU. bad grounds and corroded connections is a good place to start. To eliminate the grounding issue, just tightening the old ground may not help. The real issue is that a body ground isn't a solid connection, the steel frame and body isn't a perfect conductor, especially after 30 years. I would recommend tying all your grounds to a common point, say a point on the firewall, run a wire to the negative lead on your battery to that point, from there run another ground to the ecu and another to the plenum, that will eliminate any open or floating grounds. Also there are a lot of somewhat exposed connector in the engine bay, at the MAF, TPS, the injectors and some of the sensors. Pull the connectors and clean them up, use something like Deoxit, clean the ECU connection too, it can get pretty bad in some regions with hi humidity.


That would be a good place to start

 

Welcome to ZDriver!

Pick yourself up a free factory service manual at XenonZ32.com Reference along with the other great docs there. They will come in handy.

Your manual has all the electrical diagrams for your car - which sounds like a good place to begin your troubleshooting.

Our Z32 pros here will be happy to help.

Thanks and welcome!

 

You might check your fuel filter too, if the car had sat a while, there could be contamination in the tank, some bad fuel and walla after running a bit it fouled the filter, hopefully that isn't the problem. since you just replaced all your injectors, I would have changed the fuel filter 1st to protect that investment.

 

if the fuel pressure after the filter is good can it still be contaminated?

 

I was just guessing, assuming a running engine needs 3 things air, fuel and spark, hard to tell which it isn't getting. If you have good pressure after the filter on your fuel rail, then it might still be spark. Hopefully some of the z32 guys might have a better idea, or where to look. My vg30e experience is with the z31's, wish I could be of more help.

 

thanks anyway. found out that it definitely is not getting any spark. coilpacks are not melted or damaged. ptu has been replaced with two others and still wont get spark. relays were swapped with known good ones and still nothing. im stumped guys.

 

You might have reversed a wire some where. retrace your steps , verify everything is correct. Check you Fusible Links, not visually, but with a meter, the plastic coating can remain intact, even after the wire has melted, it is a safety feature. Could just be something simple like that, when a system has no power, step one, determine why and step one of that process is verifying fuses and connections.

 

ive shot the wires through the ptu harness and its good. shot the grounds on the connectors and they are good. pulled the CAS and turned it while key was in on and it works. the coilpack connectors are only so long and there is no way they are swapped around or reversed. checked it anyway since you suggested it and im getting desperate lol.and they were good. obviously not getting power to them but the cround wire is in fact grounded.

 

I had same problem. I put spare ECU and car is running fine.

 

ecu? intresting.. ill ask around to find one and try that out. i owe you a six pack if it works lol

 

Alex K, you sir, are a gentleman and scholar. ordered a new ECU, slapped it in and she started right up. now I can enjoy my Z. thank you all for your help.

 

I think he should get TWO six-packs. You can ship Fedex refrigerated to his home. Ask him what beer he drinks...

 

Unfortunately, I have allergy to any buzz