Hello guys,

I have searched the website for an answer but have not been able to find one.
I have a 1981 280ZX NA and when the engine is cold starts up fine, I get the fast idle and she idles down perfectly to 900 rpms and everything is great. But lets say I drive 15 minutes to the store ( engine temp reaches midway ) and I park it go to the store for 10 minutes this is what happens next.
It will start right up but immediately die, start up then immediately die, then with my foot mashed against the gas pedal, it will start up and then severly run really rough I mean it sounds like only 1 or two cylinder are firing until the rpms reach about 2000 and then it will rev up (during this time I can smell some fuel and I can hear the motor backfire through the intake a couple of times), if I let off the gas it acts like it will die but just idle terribly for about 3 minutes until I can get the Z moving. After about two minutes of driving it goes away and I have smooth idle again and full power again. My mechanic at Tidewater Z says that the cooling system is not cycling when the motor is turned off and I get an incorrect Air/fuel ratio upon start up. I am at a loss on this one guys and I am tired of sitting in the parking lot trying to get my Z going. Any help/suggestion would be greatly appreciated.

thanks,

VernonZ

 

My suggestions:

#1... Check CHTS wiring / functionality.
#2... Check AFM wiring / functionality.
#3... Check fuel pressure (charge pressure, running pressure, and after engine has been turned off pressure)... possible leak down from fuel pressure reg.
#4... Check ignitor chip (on the side of dizzy). **The ignitor is known for going faulty when old / hot.**

 

Thanks Nismopick, I will go through the checkout for those items in the factory service manual.