Joncampbe

I have a 1976 280Z that has been having big issues. Before I had to park it, the car started eating gas at 10mpg or worse. When I start it up it and it idles fine, but when I start to move, it wants to shut off. If I keep the rpm's up with my gas peddle, then I can keep it running (this requires a lot of pushing in the clutch and reving the engine while going down the road). The problem can REALLY be seen when I want to go 5mph or slower. The engine computer at my feet will start to click rapidly and then the car will shut off.

I have replaced the temp gage twice and the master air flow meter, but it still sucks gas and now WON'T run down the road, or out my drive way, without shutting off. Because of the clicking from the computer, and the fact that I think there was a leak that might have dripped on it, I was considering replacing the computer, but I wanted to see what you think first.

Help!

NismoPick

Welcome to ZDriver!

Have you checked the timing?
Fuel pressure?

Joncampbe

I haven't since this shut down problem began. Though, I had it in the shop for a complete tune up about 6 months before the shut down problem began where those were checked and the fuel milage problem persisted. Unless the fuel milage and the shutting off are two separate problems, I don't think that is the problem. The fuel milage problem had been going on for at least a year (with a weird upswing in summer) and nobody could figure out the problem, which is why those parts had been replaced and the fuel filter had also been replaced. Because of the dryness of summer and the weird upswing in fuel milage during those months last year, it was strengthening my suspicion that the problem was water related.

imd240zman

I would honestly suspect the Mass Air Flow. I had a 300zx and 280zx that both had that problem. The 280 wouldn't make it passed 45, and was a struggle getting it there. Eventually, I diagnosed the MAF as the problem, and then somehow it dropped a valve. That was the end of her.

The 300zx had a 'limp mode' for the MAF. If you unplugged the MAF and ran the car, it would run rich, but it wouldn't give you any issues. Then you plug the MAF back in, and the world would come crashing down again. I burned through 2 MAFs in 6 months, finding out I had a short in the wiring, that also took out 2 alternators.

I don't know if the 280z had limp modes, but I would start there. Even if it was recently replaced. If you have any electrical issues at all, they can affect the drive of the car.