Ok so I kept trying and trying to replicate the problem. The fuel pump actually shut down this time, I heard the pump turn off and then the truck died. The presure was steady at 55 psi and it dropped it 45 psi and shut off. Weak fuel pump?? I just replaced the relay and still the same problem.

 

There are problems with the fuel pump electrical connector - gets loose/wiggly, gets burned up. You might want to check it and see if that's the problem - if it is, replace it.

EDIT: just saw your fuel pressure #s. They're not good...I'd say it's either the pump or a failing fuel pressure regulator. Swartlkk has tests posted in the DIY section so you can tell which it is.

 

Im assuming its the pump because with all the turning off yesturday I was at 3/4 ofa tank. I drove to the gas station filled up drove for like 10 miles not a problem. Im not sure if the pump is heating up and having the extra gas is cooling it im not sure but this weekend im going to drop my tank and see whats up. I replaced the pump like 8 months ago because of previous problems which turned out to be the pulsator. So I have my AC Delco pump still and thats going back in. My advice dont buy cheap pumps.

 

That's everyone's advice.

I'm glad you already have a pump, though - because guessing can get expensive. Test the old one before you put it back in, just to make sure it's still working (you never know what sitting can do to an electrical/mechanical part).

Oh, and definitely check the connector when you drop the tank, just to make sure it's not loose or wiggly - and doesn't have any burn/char marks.

 

Just to be safe while you have the tank out I would replace the wiring inside the tank from the sending unit to the pump, its dirt cheap from napa and I have seen a broken wire inside the insulation on these a couple times on 1st gens. It could definitely explain your pump shutting off causing your truck to die.

 

Did you ever find out what was creating the stalls...I'm having the exact same problem.

 

Hey guys I'm having the same problem. It's cutting off at random while going down the road. I have replaced (with AC Delco parts) fuel pump, pulsator, and spider/regulator. Since it just dies dead as if you cut the ignition switch off, could it be something in the ignition system? I'm not sure how the fuel injection works, but is there something in the ignition system that tells the injector when to open and could there be something causing a miscommunication between the two?

 

im having the same problem too ive replaced the fuel pump,fuel filter,and fpr ive done plugs wires and new coil tested the icm and all the sensors on the plenum lets us know what the out come is my blazer has been sitting for 4 months i think its the injector but dont want to spend the money and have it not work

 

Try the ICM after a while they tend to go due to heat. Its attached on the distributor. Before that though I would get a fuel pressure guage on it anyway to see if there is any loss of pressure.

 

So your stalling also? Test the fuel pressure as mentioned above. Its possible to be an injector failing? How many miles on your truck?