ZCar Forum banner

At my wits end....(Long post)

384 Views 8 Replies 7 Participants Last post by  ACJCDAVID
I've got a 75 280z 2+2 that I've driven once from the point of purchase to home (about 60 miles or so). It drove great down the highway, but wanted to die when I finally stopped and would not start when hot. I started reading posts and set about cleaning connections. This shifted the trouble over to good start-up but it would die if you gave it the gas. Under the advice of zcar guru's I've totally rebuilt the EFI harness from a mixture of the original harness and a harness I got on ebay for $20. The original was in great shape from the firewall to the ECU and the other was great from the firewall through the engine compartment. All sensor connectors are new and every inch of wire was inspected and cleaned/replaced. Every wire has been checked for continuity from the ECU connector to the sensor/power connector. Every test in the FSM Fuel section has passed (light bulb on the injector test, AFM tests, power/ground tests, etc.) Now the car won't start at all and I can't figure out why. I've read through the archives until my eyes started to bleed and have checked everything I can think of.....here's the rest of the info:

- Replaced the AFM with a new-to-me one. All tests for it from the FSM passed.
- New NGK plugs and wires
- New Distributor Cap/Rotor
- New Fuel Filter
- New Air Filter
- Replaced all hoses that I even suspected might be worn
- Fuel pressure is right around 35 psi at the injectors

The car will crank but won't turn over...not even sputter. There's gas on the plugs after trying to start, so fuel is getting to/through the injectors. Pulled every high tension wire and tested spark....good and strong.

I'm just about ready to give up....Every wire has been tripple checked for not only continuity, but proper polarity on each sensor and the FSM is out of tests for me to run. Am I just too close to the project and can't see something I've missed?
See less See more
Not open for further replies.
1 - 9 of 9 Posts
Ignition module is bad.
OMG..... thats what I thought!! Im must be going nuts!!!!!

Best of Luck, Frank!!! Really...Best of Luck! :eek:)
replace plugs with new, let the cyls air out. then before you try and start it check the connections on the front of the t-stat housing, the thermotine sensor and temp sending wires may be crossed.
I've done the FSM checks for the ignition module that can be done without a scope....passed. I'll try Darrel's suggestion next.

Thanks everyone.
Check the fusiable links in the engine bay. Had this happen and it was a bad link.
did you check the timing? i know its seems illogical, but hey, it WOULD keep the engine from even trying to start.... andwhen your problem is bizarre, the thinking of the diagnosticator must get bizarre too :- )

also, did you make sure the AFM is properly calibrated? i know there are links somewhere in the archives to how to do this but i dont know where.

try a compression test too.. who knows, im trying to get exotic in my suggestions. strange gremlins in these cars sometimes.
Fusible links have continuity and battery voltage.

I've seen the calibration posts....I think I like the soda can one best...I'll try that one tommorrow. I had forgotten about that post. I'll try almost anything at this point and trying the free stuff is always preferrable when you're in the dog house for spending to much money at the parts store. :)

The timing and compression tests will have to wait until I get the proper tools.

Thanks again for the suggestions.
The mechanic that recently replaced one of my FI told me that he bought his first Z very cheap because the P.O. cannot figure out why the car would not run (similar to your problem). All he did was replace the "IGNITION SWITCH".

After this mechanic replaced one of my injector, he test drove the car and everything was fine. He went back to the shop and turned it off. When I got there, it would not start. Somehow the middle wire on the distributor cap, got loose. I think that is the one connected to the solenoid?

I read in one of the post in here that if you interchange the wiring of the thermotyne and water sensor, it could also cause problems like what you are experiencing now. There should be a number on the wires to double check this.

I know the feeling.

Almost parked my Z due to frustration and the fact that the wife is not happy with all the extra expenses of going to the parts store.

Good Luck and please report back on what happened once you get it running.
See less See more
1 - 9 of 9 Posts
Not open for further replies.