My 77 runs well except when restarting after it warms up. I can restart right away with no problem. If I wait 10 min or so it starts on one cylinder then two and if I start moving it will be running on all six in about 200 yards when accelerating. If I wait 30 min or so to restart there is no problem. I have no idea where to look. Any ideas or similar experience out there.

I dont know jack squat about EFI cars but i would bet its something to do with ecu overheating. Just my 2 cents.

The coil and transistor unit are frequently culprits when having these kinds of problems. Carry a can of dusting air in your car. When it is hard to start, hold the can upside down and spray the transistor unit. The liquid coming from the can will hit the unit and vaporize quickly, cooling the unit. Try starting the car again. If it starts right up, you found your problem. You can do the same to the coil and ECU. Just try one at a time to ensure you isolate the problem.

If you have exhaust leak at manifold it will heat up everything above,then when you park the temperature will rise and the fuel system

will not work properly until it cools off by air movement or cool gas from the tank.

Have a good look for exhaust leak i bet the last stud by #6 is not there and other manifold fasteners are loose or broke off.

It sounds like a garden variety "hot restart" issue to me. This is common with the 280Z -- probably an incompatibility between modern ethanol-gas formulations and our operating fuel pressure, in combination with leaky fuel system components (e.g. fuel pump check valve). Most recently it came up here:

http://www.classiczcars.com/forums/fuel-injection-s30/51224-1976-280z-fuel-injection-issues.html

Search the forum for "hot restart," and you'll be able to read lots of theories and discussions about how/why this happens and how to remedy the problem (somewhat/mostly).

I have also had similar symptoms with my 77. I'm beginning to think it's the fuel I put in my tank. During this time of the year there seem's to be a lot of "crap" added to fuels sold here in CA. At one point I was running regular unleaded 87 octane and now run 91 octane. The fuel injected Z's, in my experience, seem to like this octane better. It still has the additives in it (during certain times of the year) but mine seems to run and start better. Come to think of it I have not had that issue for a few months now. Try a higher octane if you are not now. Not saying that is going to solve the issue but worth a try. I have all new injectors (year old), connectors are clean, heat shield in place, etc etc. Still had the problem. After running a tank of 91 octane and almost forgot, ran a bottle of octane booster, and I haven't experienced the problem since.

Edited January 7, 201411 yr by rcb280z