EFI issue

[.]

I am having a problem with my EFI. I think it is fuel related. The engine will not idle. The engine will only run with the throttle at one specific position. Any more or any less and the engine wants to die. It feels like a fuel problem. But when I get the throttle in exactly the right spot it runs smooth.

 

I have replaced the fuel filter with no change to the problem.

 

I am reasonably sure the fuel pump is ok.

 

I am now thinking it is the fuel pressure regulator.

 

My logic is that if it were an injector problem it would run rough regardless of the throttle position. It feels like the fuel pressure is only enough for a specific amount of air flow. Openning the throttle makes the mixture too lean because the regulator is not forcing more pressure.

 

Is my logic sound? Any other suggestions?

 

    Thanks Greg

[PZG302]

Greg, flick me your email and I can shoot you acopy of a 280Z Electronic Fuel Injection theory and troubleshooting hand book. There could be a miriad of faults, starting with AFM, but tteh book should sort you out.

[Zedman240®]

I'd be checking airflow meter/ MAP sensor. If the airflow meter or throttle posi switch isnt telling the ECU you are on the pedal, the ECU won't know to give more fuel to rev! Test for fuel pressure by pinching the line with your fingers and then turn the ignition on. You should feel the line swell up a bit pressurising the fuel system.