Fuel pressure

Good evening,

The return line only sends excess fuel back to the tank for re use.

Dis connect the harness? What harness?

Roy

I disconnected the fuel pump wiring harness and it continues to run also disconnect both output and return line but gas it coming out of the return line. Could it be the fuel pressure regulator sticking closed?

My car problem is that when I start it up, it idles real low and when I kick the gas pedal it shuts off.

If the regulator was closed, no fuel would be coming from the return line.

As far as the pump still running, does fuel come out of the outlet of the pump? It should not pump any fuel with the connector disconnected.

Roy

Fuel comes out of outlet port. No, it's not throwing out fuel.

Okay, then the pump is not running?

Roy

Fuel comes out of outlet port. No, it's not throwing out fuel, when connected it throws out fuel. When outlet pipe disconnected and return line still connected the car is still running. How is it, still running?

Without fuel pressure it should not run at all.

It makes no sense for it to run with no fuel going to the engine.

Can you upload a video of it running with the lines disconnected?

Roy

I don't understand it either. When outlet pipe disconnected no fuel is coming out and to include fuel pump wiring harness disconnected and return line still connected the car is still running. How is it, still running? The return line feeding the engine or what?

With both lines disconnected it will not start but hook up the return line and it will start while the fuel pump wire harness is connected.

Can you upload a video of this happening?

Roy

Here it is, it's unplug but stay running.

Even if both lines are connected it shouldn't run if the fuel pump wiring harness is disconnect as shown, but it does run but very low idle.

Did you trace the lines to be sure someone did not add another inline fuel pump into the system?

Roy

Don't know about that on this make/model but I'll check let you know.

Sounds like a plan.

Roy

There's nothing to find the original piping is still there, no fuel pump. Don't know about you but this one is a nightmare. I believe this one is an electrical problem.

I agree. Wish I was there to see it and help but it it's tough from doing it from a virtual communication.

Roy

Can you give me what the EFI relay powers and what terminal? Also could this be a computer problem in your own opinion? For me it's coming down to this but I need more info to be sure. Thank you.

No, not at all. The pump cannot work without power.

I attached the diagrams you requested.

Roy

What do you meant by this; No, not at all. The pump cannot work without power.

It seem like the return line is sucking fuel back to the fuel rail when fuel pump disconnected. What do you think is doing it?