I have a 76 280z and I've had problems with it, mostly electrical. I've replaced the computer and air flow meter, but it stills runs way too rich. I'm having to clean my plugs after I drive it only for about 20 minutes. Buts that not even my biggest problem. I put a new radiator and electric fan in and i'm running with no thermostat. So it stays pretty cool, barely over 165' F. But if it gets up to about 185-190' F, which correct me if i'm wrong but thats about the normal operating temp, it cuts off and wont start until it cools back down. Is there maybe a sensor somewhere that could make this happen by sending false signals to the computer or something. Any suggestions would greatly help.

 

It sounds like your cold start switch is stuck on.

 

I've checked that before, but its been a while. I was thinking it might be my temp sensor was sending the wrong ohms to the computer, but i checked them, and its sending the signal for a little colder than what it really is, but that wouldn't make it shut off at 195'F. I dont know, I'm lost her. Thanks for the sugestion though. I'll probably go check that again to see if that causing it to run rich.

 

H is right about checking the CSV. It's a known trouble maker.
Also try:
-pressure test on the fuel line right before the rail (if the regulator is sticking, then your pressure's too high and you get too much fuel per pulse).
-test/clean the throttle position switch. If it's reading incorrectly, you might be getting idle enrichment across the whole curve.
-injectors may be dirty and not closing all the way in between pulses.
good luck,
Dave

 

Try the coolant temperature sensor located in the thermostat housing- and put a thermostat back in it! The sensor will affect your a/f ratio if it is bad- and you are confusing the #$% out of it with no thermostat!!

 

i'll definately check all those things. i'll also put the thermostat back in. i pulled it out because here in texas old radiotors dont do much for a 280z, but i got a brand new radiotor so it should be fine now. thanks for all the sugestions.

 

Also, be sure you check your TPS voltage output. It should steadly increase and not jump as you accelerate. They can act up as they heat up and get you in a crank no start mode till they cool. I don't remember the voltage off the top of my head at idle but this could also cause some of the other problems you were talking about.