91 300ZX TT cranks but won't start

[silverbullet9]

Hey guy, I've seen another post about this but, I can't figure out how to get mine started. I got the car and it had two bad turbos. So i pulled the motor and after inspecting the wiring harness I bought a new one from Z1 motorsports. The turbos are factory from another motor and are still in good shape. I also bought new downpipes and test pipes for the exhaust. After taking the motor out and swapping the turbos, putting the downpipes on and putting the motor back in, the new wiring harness was put on. Attempted to start it and it cranks but, will not start. Did an ECU diagnose and it said no malfunction. Then I noticed the security light was flashing when doors were closed and while attempting to start it. I disconnected the anti theft system from the car completely and still no luck. Took spark plugs out of car and tried to see if they were getting spark and there was nothing from that. No spark at all. Can't figure out what the problem is. Please help.

Thanks

[nissanfreak12]

Check all the grounds. For some reason if the ground isn't connected on the back of the plenum it will fry the PTU. There should be 2 on the new harnesses one by #5 and #6 coilpack.

[silverbullet9]

thanks, i'll take a look at that and post the results

[silverbullet9]

I double checked all my grounds and they're all good. Also, I picked up a new ptu, just in case and it still won't start .
I have the new style ptu that came out after the recall of the old one. I also had the old ptu as well. The new one is the style that came out after recalls.

[Rubyz32]

Have you looked through the fsm? If you have no spark, that should be fairly easy to diagnose using the steps in the fsm. It will tell you how to test the ptu. Use the new style ptu for sure. Is it brand new or "known to be good"? Are your coils good? Do you get absolutely zero spark? Are you testing for spark correctly? And how about timing? I'm having lots of trouble with my car and have tested or replaced nearly everything. Just remember, one day you'll get to drive her with the t-tops off and it will be all worth it.

[silverbullet9]

So I'm getting power to the coil packs but still no spark. I'm thinking the plugs are bad because when I got the car it was burning a lot of oil. (I think I forgot to mention that in the original post. ) going to get new plugs and hopefully that will solve the problem.

[ZL8NING]

Make sure to get the OEM ones by NGK. Don't cheap out on the plugs. About $85 shipped (set of 6) from courtesy parts. Ask your local dealership about price matching if you don't wanna wait for shipment.

Good luck.