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90 300zx crank but will not fire ( HELP Z FRIENDS!)

35K views 21 replies 5 participants last post by  Kav300zx 
#1 ·
Ok i have a 90 300zx 5 speed n/a. Everything is hooked up, and when I start the car it will crank but will not fire, fuel pump works, because, I checked the fuels lines, and pressure , and gas is coming up. I checked for spark on the plugs and grounded while doing it with my pops cranking the motor, and there is no power, so I have fuel and no power. And the other thing is to that, for every car you guys no how when the key is in the on position and all the dash lights come on with the check engine light? Then when you start the car the check engine light will go away if there is nothing wrong.? Well my car to begin with, when in the on position, all lights will show EXCEPT the check engine light. Does this mean my ecu is messed up? or my check engine light fuse is blown? and if if the check engine fuse is blown that will now allow my car to start correct?...Please help me out guys, my dad bought this for my birthday 2 3 weeks ago and now we're having problems. Those are the only problems.
 
#3 ·
I tryed to get the codes, and no codes come up at all, I put the key in, and turned it into the on position not the acc, the on one, then I turned the ecu knob thingy clockwise waited for about 3-4 seconds then turned it counterclockwise, the ecu you light that suppose to be flashing to give me codes doesn't flash, it just stays lit from the beginning of the procedures, the thing is lit and stays lit from the point when the key is in the on position, no codes are coming to me, and no check engine light is on when the key is at the on position,what you think it could be? ecu is jacked up or something else?
 
#8 ·
My bad, since you have a 90 call a nissan dealership and ask if the PTU (Power Transistor Unit) was replaced because there was a recall on the 1990 unit. You'll need to give them your VIN# to check.

I believe the recall is over but this would cause the problem you are describing.
 
#11 ·
mines is the old ptu, it is not the black box with sub harness, it is the silver aluminum looking one with fins, and also do you have any idea why would the ecu have no power?, dude checked it for me, and when the key is in the on position, ithe circiut signals doesnt reach all the way to the ecu,....so i have no damn clue whats going on but for sure I have the old ptu's.
 
#14 ·
alright, new ptu didnt help, and I got a ecu same make and model year and 5 speed, both didnt help, still same problem....please help, dude did a diagnostic, not with a conzult but he said there is no power feeding to the ecu, its a wiring problem, or a shortage somewhere, u know when u put the key in the on position the check engine light is lit? mine DO NOT, please anybody know anything? any ideas?....and my battery is new, and a new starter...all fuses are good...dont know the problem..Im sure Nissan can fix it no problem, but it would be an arm and a leg....please help me!
 
#18 ·
the problem is no power to the ecu, and i need help on what it could be..fuel pressure i have..its always been the same...nvm guys...i do appreciate your help though...its just i asked for help but i guess i have to bring it to nissan, almost 120 view and only one dude helps...real z32 know it all huh...? waste of time... but thanks sponge man, I appreciate your help.
 
#19 ·
The thing is it's hard to diagnose the problem when we don't have access to your car and can only give suggestions on how to solve problem. I'm a Z enthusiast and never once claimed I knew it all and I hope I did not come off like that to you or anyone else. Most of us are just people who like the Z so please don't bag on the z32 guys.

Ok, enough with that. I do have one last suggestion for you and that is the remove your key ignition switch and test it? If you have a Ohm reader it's easy to use with the down load of the service manual located at the top of the z32 forum.

If this does not work and the ignition is good it's time to bring to the shop.
 
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