workingprogress

ok guys figure this one out. I have a 79 zx and it dies on me after driving it for a while and it gets hard to turn over soon after. ive taken it to many different places and have done much work on it already and everyone does not know what it is or has claimed they will fix it and as i drive off from the shop its the same ****. feel im close to figuring it out but i need advice on what you guys think it might be

What ive done to the car so far:
-tune up
- Air flow meter boot to throttle
- Fuel pump regulator
- Coolant temp sensor
- fuel filter
- new Dizzy
- ic module replaced (z shop)
- relays have been checked with noid light ok (Mikes Z shop)
- cleaned all connections
- new ignition Coil
- AFM checks out fine (checked by mikes z shop)
- ECU on drivers side seems fine (was checked by Mikes Z shop )-- best shop so far

My guess is that my fuel pump is shutting off after it gets hot while driving for too long

during cold start car smells like gas. running rich most likely, turns off on me during cold starts unless im holding down peddle once warm im good to go for some while until driven for a while and then just dies and RPM tack just jolts down no bounce on shutting off. thats all i can say lets see what you guys can figure out from this

BlueKitsune

On a 79 is kinda hit or miss if it has it, but have you check the Cylinder head Temp sensor? If you have it its between the #5 and 6 Sparkplug.

Also, try unhooking the L plug on the back of the Alternator and turn your key to ON, the fuel pump should start running and stay running till the car is shut off. Yes you can start and drive the Z this way

Another thing to check maybe is the screen on the fuel pump in side from the tank, it could be plugging up. Pretty much you let it sit for awhile and the crud falls off the screen, then you run it for a bit and it sucks it all back up and cuts off the fuel flow.

SHADY280

79 doesnt have the sensor between 5+6. i had a simmilar problem, my coil wire was corroded and would loose contact and shut off the car. i also had abother car whwre the dizzy shaft was loose and was hitting the rotor to the cap. that being said youve replaced those items. i would be checking the fuel system. the smell could be from it flooding which could be the cold start valve leaking into the manifold. is there debri in your tank clogging the lines? i also had it be the ic module, but theve changed that too.

BlueKitsune

I said it can be hit and miss with a 79 if it has the CHTs.

workingprogress

yeah no, thought it was the CHT's and i changed that myself and well the issue is still their so thats out of question as for the screen on fuel pump that seems probable going to check that tomorrow ill keep you guys updated.

further advice is much accepted

lifegrddude

Is your battery and alternator in good shape? Just another thing to check since weak voltage could affect your car's fuel delivery.

workingprogress

yup battery is good alternator too

BlueKitsune

Have you tried my test of removing the L plug from the back of the alternator and tried to run the Z that way?

workingprogress

Sure did blueKitsune pumps working

noboosts130

What's your fuel pressure before the filter??

workingprogress

car was fixed. so i hope its been two days car has not died on me yet, what was changed was the fuel pump relay, hope this is it

workingprogress

Its beeen a couple of weeks and its safe to say the car is fixed thanks to mike's z shop in whitter. These guys know their z's and all other datsun cars. Mad respect to them great guys who our out to help you not bone you. I advice anyone to go to them for questions or help with their datsun/Nissan cars. Good price and honest workers, not many mechanics like these anymore.

duckyz

So... what was the issue?

BlueKitsune

The Fuel pump relay. He said it before lol

duckyz

Hmmmff.... Must've missed it somewhere.

workingprogress

Yeah the relay and a failing ic module