Helping a friend with a fuel injection problem with his 82 280Z. Anyone one here know anything about them?

When all the injectors are plugged in then engine dies. If any RANDOM one is left unplugged the engine runs with just a miss on that cylinder. He says the o2 sensor is new.

[This message has been edited by 2farnorth (edited 05-27-2009).]

Does it shut off like you are turning the key off, or does it act like it is running out of fuel? This is going to be a good one... I'd say tow it to my shop and let me have a go at it!

Will it restart after it dies with all the injectors plugged in?
Are the injectors the correct ones for the car?
How many amps are they pulling with 5 plugged in? all 6?
Ground wires ok, connections clean?

All I can think of now, my older brother was big into the 280z's and 280zx's. Been awhile since I wrenched on though.

[This message has been edited by topher_time (edited 05-27-2009).]

How does it run/ rev with one unplugged. Does it get starved for fuel?

Could also be a bad ECM...

It dies like the key was turned off. No sputtering, hic ups or coughing. He's got a fuel pressure gauge under the hood and is going to watch how it reacts when he plugs the sixth one back in. He said it runs normally at about 37#.

He's also swapped out the injector harness, ecm, and fuel pump chasing this problem. The problem started after an engine swap. He did say that the PO had by-passed the fuel pump relay and that it is running direct/continuous with key on. He said the fuel filter is new and the lines "appear" to be in good condition.

Is there a fuel pressure regulator in the system? I can't find much tech data on line about the car.

edit: He's also going to check voltage and current on the injector harness this weekend. I probably won't have a chance to talk to him again til then.

[This message has been edited by 2farnorth (edited 05-27-2009).]

I would look for the ground wire going to the engine, Intake. It sounds like a ground getting too much resistance, high amp loads always suffer.

I have rebuilt one from the ground up.
The air flow meter is the biggest fault with the fuel system.
The pressure regulator should be near the middle of the fuel rail. The fuel pressure regulator should keep the fuel pressure at 36-37 psi at idle without vacuum at the pressure regulator.
The injector system is controlled through the coil. Basically, the coil tells the ECM when to trigger the injectors to fire. They all fire at the same time.
This may help:



-Dave

I appreciate the responses. When I get home I'll get this info to him. (My wife is in surgery right now)
I'm thinking maybe as suggested above there may be a ground problem. At least that is a good place to start.

Dave