1976 280 Z No power

[Behare]

I have a 1976 280 Z. I was running well until I took it to have an oil change. Since then it has not run well at all. I assume that it is just happend at the same time. I have checked the fuel pressure. I have 32 pounds of pressure at the filter both with the engine running and not running. I ran Seafoam through the system and checked the compression. I have 125 to 140 on 5 of the six cylinders. The 6th one has on it. I need to recheck it to make sure that I didn't miss something. I have drained the fuel tank and changed the fuel filter twice since it got. I sat for ten years before I bought it. The car will run until it warms up and then it looses power and backfires. I can only go about 10 mph with the gas pedal all the way down. I disconnected the cold start injector to make sure that it wasn't leaking. I pulled the plugs and the are black and appear to have oil on them. I would appreciate any and all help that I can get. Thanks for your help.

Edited October 12, 2010 by Behare

[Behare]

I also took the oil fill cap off and the engine died so I am assuming that the vacuum is where it should be.

[Zed Head]

Did you have the oil changed at one of the name brand quick oil change shops or the local mechanic? Maybe someone took a joyride.

32 psi is below the 36 psi recommended in the FSM. But your black plugs suggest rich running so that doesn't really fit your picture since low pressure should run lean.

You didn't put a number on cylinder #6 - "The 6th one has on it." ????

You say the car will run until it warms up. Do you mean it will actually drive down the road like a normal car when cold, then lose power when it gets warmed up? Or it will run in the driveway, then backfire when you give it gas after it warms up?

[Behare]

The cylinder with the low compression has 30 on it. The car will run down the road for about 10 minutes and then it starts to loose power and backfire.

[buysell]

Just a random thought, did they over fill the oil?

[Shutdown]

My 1979 280zx has similar symptoms, I replaced the plugs and wires, I'm going to check the points and timing today. I've read a lot of suggestions to adjust the MAF although I'm not sure if it should be turned to the right or the left.

Are you experiencing any backfires into the intake manifold like I am?

[sblake01]

That would be a neat trick to adjust the MAF since a 1979 280zx doesn't have one. That, and the fact that a MAF sensor has no adjustment. I wouldn't suggest adjusting the AFM (which is really what you mean) without some way of reading the results of the adjustment.

Edited January 18, 2011 by sblake01

[Shutdown]

I stand corrected!