Still having injector issues

[Kitch]

I can't quite see how an injector problem could make the fuel pressure bounce between 12-15 PSI.
My fuel pressure is set to 20 PSI and never moves on the gauge from idle to W.O.T.
So even if your injectors were failing somehow or getting blocked that shouldn't show up on your fuel pressure gauge.

I'd be thinking fuel pump or power supply to fuel pump.
Fuel pressure regulator or venting problem with gas tank maybe?

[1project2many]

When the injectors are acting up the fuel pressure gauge is fluctuating between 12-15 at idle

How is this presenting? Is the pressure needle slowly swinging between the high an low? Ir is the needle dropping rapidly, possibly with each injector event?

I'd be thinking fuel pump or power supply to fuel pump.
Fuel pressure regulator or venting problem with gas tank maybe?

Right. First question: Are you using a vacuum referenced pressure regulator? If not the fuel pressure should be very consistent. How the fluctuation presents can help aid in diagnosis. Fast drops may indicate an issue with the volume of fuel being delivered. Slower drops may indicate electrical issues.

[Dieselsj]

How is this presenting? Is the pressure needle slowly swinging between the high an low? Ir is the needle dropping rapidly, possibly with each injector event?



Right. First question: Are you using a vacuum referenced pressure regulator? If not the fuel pressure should be very consistent. How the fluctuation presents can help aid in diagnosis. Fast drops may indicate an issue with the volume of fuel being delivered. Slower drops may indicate electrical issues.

It is fluctuating quickly when it is running like crap. Rapid like with each injection event. But when I get the engine above the RPM where it is acting up the pressure holds rock steady. I have brand new later model (higher pressure) pumps in both tanks and it acts the same no matter which tank I have it on. This is also the 2nd regulator I have tried as I originally thought the issue was with the regulator. And it is so rich at idle that it seems an injector is sticking open which is causing the pressure drop.

Has anyone ever cut open a TBI injector?

[stew86MCSS396]

http://gearhead-efi.com/Fuel-Injecti...ohn-Wilson-PDF

This was an anomaly that we've experienced and in no way I'm saying this is your problem. A little background, this was an unregistered vehicle that could not be driven and we encountered this issue sitting in the stall. I'm sure had we been driving and datalogging, may have seen different results. You can ignore the thread just read comments on page 3...

http://gearhead-efi.com/Fuel-Injecti...-TBI-PCM/page3