03 Silverado 1500 4.3 crank but no start. 0 fuel pressure. Details below

[Pierre-Nicolas Minjauw]

Hi! So about 2 months ago my fuel pump went out. Had it replaced and right away we noticed sometimes it would crank but No start. After a few days the pump was defective, so replaced it again. Pump ran great with good pressure but after about a week or so, same issue crank but no start. Sprayed some starter in the manifold sometimes start, sometimes no. Turn key on/off to cycle and then sometimes start, sometimes no. Used the pressure valve behind the spider to bleed air/fuel then engine start fine. Would run fine for a couple days up to a week and then same thing all over again. Took it to local chevy. Diagnosed fuel pump, ... good to go they said, everything working properly. 2 days later No start and this time cannot get it to turn over, pressure is at zero. Pump is still turning on but not humming like it was. Replaced MAF and distributor cap as well as fuel filter. My local mechanic and I are stumped, and I'm already $1000 in on repairs. Please help!

[richard wysong]

take it back to Chevy. they replaced the pump correct? if theres no FP the hose on the pump may have a problem

[Pierre-Nicolas Minjauw]

Chevy did not replace the pump, my mechanic did. We took it to get diagnosed at Chevy after the fact because we were still having issues

[richard wysong]

if the pumps running but not making pressure its either a bad pump or the small hose that connects the pump to the sending unit has a problem. if its another bad pump change brands, that is not where you want to try and save money by buying low $ parts. 

[Pierre-Nicolas Minjauw]

Ok do you think all the other issues are related to the pump?

[richard wysong]

more than likely. its not going to run without fuel pressure so thats got to be fixed before you can continue the diagnosing. have you checked for any fuel flow, not just pressure? I have seen that small hose split before and it would still flow fuel but no pressure. are you changing the fuel pump module each time or just the pump? i learned years ago to bite the bullet and spend the extra $ for a GM pump rather than drop the tank twice 

[dna9656]

I installed a Delphi FG0815 Fuel Pump Module 5 years ago. No problems. I don't know if this is/was GM's supplier but I do remember Delphi being a major supplier to the Big Three. I got it on Amazon for $183.39.

[Pierre-Nicolas Minjauw]

We replaced the pump again. The pump had a blown hose in the return line, again for the second time, we went with a different brand this time of course. Is there anything that could cause this problem besides a crappy pump manufacturer?

[richard wysong]

not really, running it dry may damage it as it uses the fuel to cool itself. if it didn't have the filter sock on it it could suck up any crap in the tank that could damage it as well.  you should probably check to make sure it's getting good power and ground while you have it running. should be close to battery voltage if you can get at the connector to check

[richard wysong]

no sign of any thing in the gas tank I assume (sugar,flour, dirt etc)

[richard wysong]

blown hose on the return line? the return line is just that it returns excess fuel to the tank, not under pressure. are you replacing the fuel pump module or taking it apart to change just the pump?

[richard wysong]

so I replaced the fuel pump today in a 86 s10 that had been sitting for a couple years ( not a module type pump ) and found that the hose that connects the pump to the pipe had completely disintegrated. I'm guessing the alcohol in the gas caused this. much easier to remove the bed than the tank on this rust free antique

[Gagliano7]

Make sure your fuel lines aren't clogged and check fuel filter.

Edited March 25, 2022 by Gagliano7