2003 Silverado Won't Start...:(

ChevMech · February 15, 2015

I've been kicking myself in the @$$ for the past week over this and I just want to put it behind me....but the truck just won't have it. Here it goes....

My cousin told me his '03 Silverado with the 4.3l V6 was getting hard to start, and then wanted to hesitate when he got to highway speed. My first thought was fuel filter. I replaced it and it was full of junk. I then got to looking on the interwebs and saw that the fuel regulator could be the source of the problem. I took the top part of the intake apart and replaced the fuel regulator. When I put it back together and hit the switch, the regulator blew off and filled the back two cylinders with fuel, hydrolocking the engine. I took everything back apart and notice there was an o-ring from the old regulator was still there. Everything fell back together after that.

I took out all the plugs to let the gas out. I pulled the fuel pump relay, but in my frustration, I overlooked pulling the coil wire as to not have spark at the wires. Well, as you can imagine, when I turned the engine over to push the fuel out, one of the wires jumped an arc and I have a fire on my hands. I managed to kill it before it did any more damage than messing up some of the hood insulation.

I replaced the plugs this evening and made sure everything was as it should be. Now the truck won't start. I'm really at a loss as to where to start looking again. The fuel pump is turning on, and I can't figure out why it wouldn't be firing. Any ideas as to what I screwed up?

oldscsc · February 15, 2015

I suggest checking fuel pressure at the Schrader valve on the rail. The fuel pump is a common failure in these trucks (actually most GM's around this time...). It may be the source of all the issues in the first place.

Btuggle88 · February 16, 2015

+1^^^. I agree check the fuel pump I've seen them in the past burn up trying to push fuel through a clogged up filter and they will cut in and out causing problems and stranding you when ever it feels like it.

ChevMech · February 16, 2015

Thanks for your responses. I rented a fuel pressure tester yesterday from O'reilly's and tried it. The fuel pump built up pressure to 60 psi, but as soon as it cut off we were back at 0. From what I read, it is supposed to hold at least 6 psi. Google doesn't always provide the best of information. Anyway, instead of throwing more parts into it, and getting all kind of parts, I took the truck to my mechanic. I will let you know what he tells me when he digs into it.

CapitalTruck · February 20, 2015

Thanks for your responses. I rented a fuel pressure tester yesterday from O'reilly's and tried it. The fuel pump built up pressure to 60 psi, but as soon as it cut off we were back at 0. From what I read, it is supposed to hold at least 6 psi. Google doesn't always provide the best of information. Anyway, instead of throwing more parts into it, and getting all kind of parts, I took the truck to my mechanic. I will let you know what he tells me when he digs into it.

You hear anything yet?

ChevMech · February 20, 2015

I've been dreading having to post this haha. I talked to my mechanic/cousin and he was able to get the engine started. Unfortunately, the news wasn't good. He said that it had a knocking like something was sitting on top of the piston, which leaves us with two options. We can 1. Pull the head and see what's there, or 2. Drop a wrecking yard engine in it.

Being who I am, I would pull the head and see what's under there. Having someone else do it would cost roughly $900 in labor alone and, if the engine is ruined to begin with, would be wasted if a new one is needed. It has been quoted to me that a new engine would be $2300 out the door. Now we wait to see what the owners want to do with it.....

sahls01gmc · February 20, 2015

How difficult/expensive is a V8 upgrade?!?

ChevMech · February 21, 2015

I thought about suggesting a 4.8 or 5.3 upgrade, but since I'm not doing the work myself, I doubt it will go over very well. The question is, How different are the motor mount locations and the transmissions? I know you would have to change or reprogram the PCM.

And just thinking aloud here, you would have to change the front wiring harness. The 6 cylinder has a distributor, while the 8 has coil packs....