2003 Gmc Sonoma Zr2 4x4 4.3l Won't Start

MitchFromPEI · January 8, 2010

Well after a long drive I parked my truck for two days. This morning it would not start. It would turn over but no start. Seems like it is not getting fuel, I havent had much time to test as i'm back in college right now. But I suspect the fuel pump becuase I no longer hear that "whine" when I turn the key forward. I pulled the relay and put 12v across the relay and it drew in and I got continuity on the normally open points. So it seems fine. But my car pool showed up and I had to go. Which fuse is it in the fuse box I should check when I get home. And where exactly is that red wire I can put 12v+ on and test the pump myself? Also, how hard is it to get at the pump and test for voltage at the pump?

MitchFromPEI · January 8, 2010

Well after a long drive I parked my truck for two days. This morning it would not start. It would turn over but no start. Seems like it is not getting fuel, I havent had much time to test as i'm back in college right now. But I suspect the fuel pump becuase I no longer hear that "whine" when I turn the key forward. I pulled the relay and put 12v across the relay and it drew in and I got continuity on the normally open points. So it seems fine. But my car pool showed up and I had to go. Which fuse is it in the fuse box I should check when I get home. And where exactly is that red wire I can put 12v+ on and test the pump myself? Also, how hard is it to get at the pump and test for voltage at the pump?

Like what red wire is the book referring too, pulling that wiring harness apart then putting voltage to the red wire? Confused with that step. Also what fuse should I check that is blown for the fuel pump? Fuse box diagram doesnt show and fuel pump fuse. Just relay. PS I found a blown fuse on the oxy sensor... replaced that. Didnt help.

MitchFromPEI · January 8, 2010

Little bit of a one way conversation, but maybe someone can learn from what i've done. I read on a site to give the gas tank a wallopp with a rubber mallet. I didn't have a mallet so I pounded it with my hand. Sure enough the pump came to life next time I tried to start it. I'm guessing this is a sure sign to replace the pump?

MS3DALE · January 10, 2010

Yep,Kinda' sounds like the fuel pumps going bad to me.

MitchFromPEI · January 10, 2010

Yep,Kinda' sounds like the fuel pumps going bad to me.

It's easier to just slide the box back is it?

MS3DALE · January 10, 2010

Yep,Kinda' sounds like the fuel pumps going bad to me.

It's easier to just slide the box back is it?

Yeah,Thats what a lot of the techs I know do,they actually use the lift/hoist to raise it up out of the way.

MitchFromPEI · January 10, 2010

Yep,Kinda' sounds like the fuel pumps going bad to me.

It's easier to just slide the box back is it?

Yeah,Thats what a lot of the techs I know do,they actually use the lift/hoist to raise it up out of the way.

Wonder if that is the best option for a driveway mechanic. I could get a friend or two to stop by and help lift it back a bit if that's all it takes. Frame bolts and gas filler/wire harness.

MS3DALE · January 10, 2010

Yep,Kinda' sounds like the fuel pumps going bad to me.

It's easier to just slide the box back is it?

Yeah,Thats what a lot of the techs I know do,they actually use the lift/hoist to raise it up out of the way.

Wonder if that is the best option for a driveway mechanic. I could get a friend or two to stop by and help lift it back a bit if that's all it takes. Frame bolts and gas filler/wire harness.

Yep,Preferably get three buddies to help,that way theres one of you on each corner.