Fuel Problem???? Help Please

[mrardente@mac.c]

I just got a 77 280z and its in great shape other than the fact that it doesn't run. It has many many new parts and only 112k miles. it will crank and stay on for a minute or two and then just sputter out and slowly die, as if its running out of gas. fuel injectors look new, I put a new fuel pump in and still the same problem. the last owner said it might be the fuel injector relay...replaced and still the same thing. would it be something as small as a inline fuel filter or something bigger? any suggestions would help alot.

Thanks

[mriz]

Congartulations on you Z! Has the car been sitting for a while? Did you drain the tank when you changed the pump? If not I would start there.There is a 12mm bolt on the passenger side on bottom of the tank .Drain a gallon and see what comes out. Check the screen on your old pump to see if it was cloged also. Start with basic tests before it gets too expensive changing out good parts. While waiting for more help there is a lot of info in the search function which will give you some ideas on trouble shooting. Good luck ,Jim

[mrardente@mac.c]

thanks for the advice! I talked to the lady and its been the same gas for the last four years. so I'm thinking that is the issue. I hope at least

[sblake01]

The same gas for the last four years? So the car has basically been sitting for four years, without running? Mine was the same way when I bought it only it had been sitting for almost five years. You'll have to either remove and properly clean the gas tank or replace it.

[m4xwellmurd3r]

that's pretty much how mine is. it's running better now, but won't run good till you hold it around 2k for a little bit. and once it hits idle, it runs nasty again.

the fuel lines/fuel tank is probably crudded up, and will need cleaning.

simple enough, just a bit time consuming for me (since i'm the only one working on mine, outside, in the sun.

good luck on your car. it sounds like you're fighting the same gremlins i'm fighting.

[sblake01]

It'll run even better once you tend to the tank. What's probably happening is at 2500rpm you have enough fuel pressure to make it more or less run okay but I'll bet it's still not up to spec due to the crud in the tank. At idle the pressure drops even more. That's how mine was. I cleaned out all the lines, changed the filter a few times, but the problem still persisted until I changed the tank.

[m4xwellmurd3r]

I'll bet too, that crud has built up on mostly numbers 1,3,4,5. because those are the wicked lean cylinders. 2 and 6 are extremely rich. it would make sense then, that the higher rpms would cause the fuel pressure to push past the crud on those cylinders, but at the same time, the excess pressure caused by the crud, would cause numbers 2 and 6 to run even more rich (maybe even forcing fuel through the injectors?)

[sblake01]

There's really no excess pressure. Before I replaced my tank, the fuel pressure would only get up to about 27-29 at best. At idle it was even lower, not enough to properly sustain the idle. It's supposed to be 36.3. It eventually would clog up to where it would die upon any kind of acceleration. After changing the tank and obtaining proper fuel pressure, I did have to replace a couple of injectors. It's hard to really know what's going on with the injectors if the fuel pressure is off.