Engine stalls while driving?

I see you replaced the pump but you have a return fuel system which means the regulator will route "excess" pressure or fuel back to the tank. We need to check the return system for issues including restrictions. However, I suspect the regulator may be allowing too much fuel or pressure back to the tank which causes your low pressure. The reason is, your running pressure should be a minimum of 30 PSI so it is not that far out but with a new pump you would expect it to be higher so that means one of three things. First it is a weak pump. Second, you have a restriction in the supply line, or there is a "leak" in the system allowing pressure to bleed off to the tank.

Let me know if you have questions and we can go from there. Thanks

Fuel pressure should be 35-45 psi. I would suggest replacing the regulator.

OE instructions below.

Let me know if this helps.

Rich

Good afternoon,

If you only have 28 pounds, it is a fuel pump issue.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I attached the spec for you.

What brand pump did you use?

Roy

The new fuel pump was made by car quest. Don't know what brand the new pressure regulator is and the running pressure is 28 psi, no higher. It wont keep a constant idle. I have to check the rpm with the obd 2 that I bought because truck wasn't made with a rpm meter and which lines on the fuel pump is the return line? Thanks in advance.

The large line goes to the fuel rail and the smaller line is the return line form the rail.

When it shuts off, does it start right back up?

https://www.2carpros.com/articles/stall-at-idle

Roy

Yes, will usually run for a few minutes then instantly shuts off and cranks back up and run few minutes and shuts off again. Wish could talk on phone. I'm a bad typer.

When I first got it I was told it had a bad EGR valve. Replaced that. IAC valve, MAF, fuel pump, filter, pressure switch. Checked inertia switch. Checked for vacuum leaks with starter fluid. Alternator, battery. Bought pressure tester. Checked all fuses and relays. And bought a obd2.

No check engine light on.

Also cleaned the throttle body and the mass air flow area and filter and put on a new throttle position sensor.

Can I test the pressure straight from the pump?

You can but it will read the same as at the rail.

I think your new pump is either wrong or bad.

Roy

Okay, thanks Roy. I'm going to clean the return line first and if that does not help. Off with the pump. Thanks

You are welcome.

Always glad to help.

Keep me updated.

Roy

Took it back for another pump and now pressure is lower.

That's idling pressure.

Yep, you need a pump.

Replace it and ask either for an AC delco or delphi pump.

Roy

This is the second new one I put on. First was a Carquest. This one is a Airtex. How long should line hold pressure? Mine loses pressure within seconds of it shutting off.

It should only drop about 3-5 pounds.

There is a check valve in the pump that keeps residual pressure. If that is not holding, it will bleed down.

When you drop the tank. Look inside for any debris or dirt in the tank.

Roy

I have the bed off of my truck and the inside of the tank is clean.

Okay, check the pressure when you install the pump.

Roy