Stalling while driving.

[rockola1971]

Update;
Test 1- fuel pressure:
With new Guage hooked up, key on, it reads 54 psi, but then it slowly (30-60secs) drops down to 38 and lower. Chilton says it should be between 55 & 62. The tps made a loud click before the pressure started to drop.
Started the engine and the fuel pressure jumped to 55 and held at idle but the needle vibrated the whole time. It was just the engine running I'm sure.
Chilton says if the pressure is low, it's indicative of clogged fuel lines, fuel filter or a faulty pressure regulator, both of which are part of the fuel pump assembly, in the FULL gas tank. I was guessing the regulator or filter when it was stalling out, especially since it started right up again.
Just for grins I'll test the tps. That's what a buddy says it is.

That TPS isnt causing you to have low fuel pressure. Your faulty fuel pump is. "38psi and lower" as you stated aint gonna cut it for a 5.3/6.0....Unless you have a fuel filter on the frame rail drivers side then it could be that. It takes an ungodly amount of debris to plug up the sock at the fuel pump. The old sugar in the tank method sure will do it but natural debris acquired by gas stations likely are never the cause.

 

[Skunkape]

Update 2;
I have been driving all over creation and it has not repeated the stalling issue. The guage has been everywhere, but I haven't let it get below an 1/8 of a tank. Go figure. I'm leaning towards the fuel pump though, because since I've been paying attention to it, it seems it's not as powerful or zippy as usual. Fuel mileage seems to be off also.
I did run some real-time scans and the tps and pedal are communicating with no issues. The left and right bank fuel trims appear to be within desired values, however on the low side (if I'm reading it right) through low rpm ranges on a typical drive.

Thanks for input and I will keep you posted.

 

[viven44]

If you have a frame mount fuel filter, if it’s clogged it could affect pressure… the clog may be intermittent depending on the particulates and where they are … when you turn off the vehicle any backflow can temporarily unclog .. similar to any filter in oil pickup tubes in engine/trans

 

[Skunkape]

Update 3;
The stalling issue has still never repeated, but I blew out a brake line. Since the gas tank had to be dropped to make the repair, I figured I would go ahead and replace the fuel pump while it was down. This entire project was a horror story from beginning to end, and now that it's running and stopping great, the $%#@& fuel guage is reading less than 1/2 tank after a fill-up.

 

[OR VietVet]

Update 3;
The stalling issue has still never repeated, but I blew out a brake line. Since the gas tank had to be dropped to make the repair, I figured I would go ahead and replace the fuel pump while it was down. This entire project was a horror story from beginning to end, and now that it's running and stopping great, the $%#@& fuel guage is reading less than 1/2 tank after a fill-up.

Did you replace with a complete AC Delco unit or genuine GM unit or did you do, just the pump, and no sending unit?

 

[Jobi-Wan Kenobi]

If you do still have random shutdowns the crank position sensor can cause that and not trigger fault codes.

 

[Skunkape]

Did you replace with a complete AC Delco unit or genuine GM unit or did you do, just the pump, and no sending unit?

Replaced with a complete Delphi unit. I was getting worried that I boogered the float assembly upon install, but I remembered that the guage has stuck before. Haven't had a problem recently, before the new pump, but the guage cluster is messed up; typical for GM. That's where I'm hanging my hat for now. Not sure when or if I'll ever get the cluster fixed, but I sure don't want to drop the tank again.

 

[Skunkape]

If you do still have random shutdowns the crank position sensor can cause that and not trigger fault codes.

Yeah I read that somewhere, but I was thinking it was Camshaft position sensor. Either way, it hasn't done that again.

 

[OR VietVet]

Replaced with a complete Delphi unit. I was getting worried that I boogered the float assembly upon install, but I remembered that the guage has stuck before. Haven't had a problem recently, before the new pump, but the guage cluster is messed up; typical for GM. That's where I'm hanging my hat for now. Not sure when or if I'll ever get the cluster fixed, but I sure don't want to drop the tank again.

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