Truck is not getting fuel

[DuallyGuy]

My truck shut off on me yesterday while on the freeway. I tried putting gas which didn't work. I had it towed to my house. Both fuel pump relays have been replaced. I don't hear the fuel pump when I turn the key on anymore. Before I start the fear the worst, is there anything else I can check for? I've tried toggling over to the other tank but the truck still gets no fuel. All fuses are good. I thought she was running a little sluggish the past couple days but wasn't too sure. She's dead in the water. Any help would be appreciated.

 

[foamypirate]

There should be a red wire with a small connector coming off of the fuel relay connector. That's the test connector for the fuel pump. Try providing 12V to that wire and see if the pumps kick on. If so, the problem is before the relay or the relay itself (not likely since you replaced though). It's possible the oil pressure switch is bad if that's the case. Power to the fuel pumps feeds through the switch.

 

[DuallyGuy]

I always wondered what that red wire was for. Ok sounds good. What's funny is i accidentally knocked the oil pressure switch yesterday while trying to put new belts on the truck. That would be great if that solved the problem. Thanks a lot. I'll give it a shot.

 

[DuallyGuy]

I ran into a problem. I noticed that the oil pressure switch was screwed into a brass fitting which also had another oil pressure switch screwed into it as well. The brass fitting is what was screwed into the block. Unfortunately, it snapped off as I was trying to remove it. So now I have a hollow threaded piece broken off in the block. Luckily it's hollow and shouldn't be too hard to extract. But my question is, why are there two different oil pressure switches screwed into the brass fitting? The other switch is the kind with a plastic end which should have some sort of 2 prong plug snapped into it, but nothing was plugged into it and I found no plug or wire to plug into it. Does that sound right? My truck has no oil light. Just an oil pressure gauge. (I think) I just want to make sure I need to replace the brass fitting with two different oil pressure switches just like I found it.

 

[smurph20]

On fuel injected trucks one is for the oil pressure gauge the other is for the computer to tell the fuel pump it is safe to pump fuel basically. As long as it has pressure the fuel pump runs. No oil pressure no fuel. This happened on my S-10 years ago took me a few days t figure out the oil pressure switch for the computer was shorted out.

 

[DuallyGuy]

This is what I found.

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[smurph20]

Yup all metal one is for the gauge and the plastic one is for the computer telling it to power the fuel pump.

 

[DuallyGuy]

Hmm the strange thing is that there was no wire running from the plastic plug. I searched and didn't see anything dangling. How was the fuel pump working then? Thanks for your info by the way. So that means that everything in the photo must be replaced?

 

[foamypirate]

Hmm the strange thing is that there was no wire running from the plastic plug. I searched and didn't see anything dangling. How was the fuel pump working then? Thanks for your info by the way. So that means that everything in the photo must be replaced?

It's possible someone may have bypassed it for some reason...but in any case, you will need to replace the brass fitting.

 

[89Suburban]

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[DuallyGuy]

I bought this truck a year ago and I'm still going through it trying to repair things. In the first photo, I found 3 orange wires. One of them turns into blue which connects to the oil pressure switch. The other two orange wires were cut off. I'm assuming these are the wires for the electronic oil pressure switch. I will check through the charts above to confirm. Then in the 2nd and 3rd photos, I found this other connector all melted and also covered with tape hiding near the passenger side of the throttle body. I have NO idea where this thing belongs. If anyone knows, please let me know. Thanks a lot. And thanks you everyone for the great info. It is much appreciated.

 

[DuallyGuy]

I put new oil press switches with a shiny new pig tail. Still no fuel. I noticed my ecm B fuse keeps blowing. Any suggestions? I just replaced the ecm b fuse and it started. I replaced that same fuse 2 days ago and nothing. It just started but it kept choking out and dying the first few attempts but now she's running. But I still don't know what happened or why.