300zx wont start?HHHHHHHHHHEEEEEEEEEELLPP!!

[sdkid123]

1990 300zx na Just put engine and transmission in my z and it wont start??! Engine turns over but it wont start?I pulled the spark plugs and they are dry?Timming belt is good i counted the cogs and everything.. how can i check if im getting fuel and spark?Also does it matter if im using the same ecu from my old engine?

[Ace2cool]

No, an N/A ecu is an N/A ECU. Easiest way to check spark is to pull a plug, ground the threads of the plug out on the plenum, and have someone crank the engine. If there's spark, you're looking at another problem.

Do you hear the fuel pump prime when you turn the key to the "ON" position?

[sdkid123]

No, an N/A ecu is an N/A ECU. Easiest way to check spark is to pull a plug, ground the threads of the plug out on the plenum, and have someone crank the engine. If there's spark, you're looking at another problem.

Do you hear the fuel pump prime when you turn the key to the "ON" position?

yes i can hear the fuel pump when i turn the key on

as for the plugs i pull a plug ground thethread to the plenum with the coil pack on the plug and crank the engine?

[Ace2cool]

Yes.

[sdkid123]

k i will check tommorow but how can i check if injetors are getting fuel?i heard putting led's on connectors?

[sdkid123]

No, an N/A ecu is an N/A ECU. Easiest way to check spark is to pull a plug, ground the threads of the plug out on the plenum, and have someone crank the engine. If there's spark, you're looking at another problem.

Do you hear the fuel pump prime when you turn the key to the "ON" position?

i checked last night and i have spark but no fuel to injectors???I unpluged the coils and turned the cas by hand to see which ones were getting fuel..i pulled the spark plugs and only cylinder number six was getting fuel???


Things i have checked:
turned cas by hand fuel pump primes,i checked fuses next to battery there all good,checked fuses under steering wheel all good,i also checked the egi and the ign coil green cube fuses they seem to be fine ,injectors read 12.9 ohm all of them,i have the older style ptu but it is working i have spark

What might be causing the problem?thanks

[Ace2cool]

Have you checked your EFI harness? On a '90, if the harness has never been replaced, it's coming about time. The harness wires get old and brittle and finally break. Having recently had the engine out, that's a lot of stress/movement that the harness normally doesn't see from day-to-day use.

Just spitballing here. Anyone else have any ideas?

[sdkid123]

Have you checked your EFI harness? On a '90, if the harness has never been replaced, it's coming about time. The harness wires get old and brittle and finally break. Having recently had the engine out, that's a lot of stress/movement that the harness normally doesn't see from day-to-day use.

Just spitballing here. Anyone else have any ideas?

hey thanks for the reply My harness is preety old im going to check today if the injectors are getting the signal to open
Im starting to believe that they got clogged up or something

[CrazedZ32Owner]

did you pull the injectors out of the fuel rail??

[sdkid123]

did you pull the injectors out of the fuel rail??

I decided to take the injectors out of my old engine and connect them to the wiring harness to see I they would shoot out gas and they all did so that means that the injecors in the engine that's in my car right now are all clogged up excEpt for one....tomorrow I will swap out the fuel rails with injecTors:/

[sdkid123]

hey i found the problem it was the injectors thatnks for yor help

[Ace2cool]

So they ohmed correctly, but didn't fire?

[sdkid123]

So they ohmed correctly, but didn't fire?

Correct they were all at 12.9 but only one of them spit gas

[Ace2cool]

Very odd. Good info, nonetheless.

[sdkid123]

Yeah I get they got clogged or something?.do you know what would cause my engine to rev uP byitself?

[Ace2cool]

Vacuum leak or a sensor somewhere. Check your coolant temp sensor. I've seen it do weird things on Hondas and Subarus as far as jumping up the RPMs.

[sdkid123]

Vacuum leak or a sensor somewhere. Check your coolant temp sensor. I've seen it do weird things on Hondas and Subarus as far as jumping up the RPMs.

Fixed it it was the iac