Car won't start, likely electrical issue

[Sgt]

Hey

My buddy has a 1990 300zx 2+0 TT. His car doesn't start. It turns over and every few seconds I hear one cylinder fire. He initially started frying coil packs, so re replaced and re-wired his PTU. I have gone over the wiring a few times and I am quite confident in saying thats straightened out now. The PTU is the new style also. He replaced the fried coil packs with brand new ones.

We pulled his spark plugs and they are wet after trying to start so I think its an ignition issue and not fuel.
Someone tried suggesting unplugging the MAF to see if that made any difference (which it did not).
I have tested the harness itself to make sure there was no broken wires in the ignition system which I didn't find anything in.
I'm sure I have forgotten to mention a few things I've tried already but I'm almost dry for ideas now.

We have played around with the ignition timing with no success.
He does have the stock cats in and his car is at 200,000km (120,000miles). Would this cause a starting issue if they were plugged? I think its grasping at straws.

Next thing I wanted to try was testing each individual cylinder for spark with a timing light to make sure they are all sparking. I'm pretty confused at this point.

Advice??
Thanks guys!

[marty1mc]

First, pull the codes. The ECU may be logging an error that can help you. Next, I think your idea to check spark at each cylinder is a good one. If you don't have spark, work backward toward the PTU. Make sure to check the PTU harness as well. I have seen those go bad and give similar results.

[Sgt]

Ran an ECU diagnostics, no faults. Tried starting it and then checked again with no faults. I am going to replace the fuel filter and see if that helps.

[Sgt]

Wasn't the fuel filter but while testing that I realized when he replaced the coil packs he didnt put the brackets they bolt down by. Thats 4 packs without the brackets and 2 with. Are the brackets a ground at all? I'd just test that out, except he can't find them. Could this cause an issue?

[Sgt]

Bump

[ZeeTree]

Yes, Im pretty sure those brackets need to be connected. That might be why you hear a couple cylinders fire. Good luck