No Fuel

mirae1

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I have a 1995 GMC Yukon. It has been a good vehicle for the most part. I have 260000 miles on it so it is getting pretty tired but has always run good. The other day I was at a friends house and it wouldn't crank. Tried jumping it and no luck. Friend gave me a ride home and I came back the next day to tow it home. Decided to see if it would crank and it fired right up as if nothing was wrong. (it was about 20 degrees out). Driving it home it suddenly lost power on a slight hill but took off again. Made it almost home and it died. Due to the cold I thought maybe a fuel line freezeup. Towed it on home and put it in the shop and put some Heet in the fuel tank. A couple days later went out and gave it a try and it would crank but would not start.
Checking the system I found I was not getting any fuel to the TBI. Fuses and relay were fine. I thought I could hear the fuel pump running (don't hear as well as I use to). Purchased a new fuel pump and just got it put in. Same Issue. Can some one explain the fuel pump circuit. IO know the oil pressure switch is tied to it. Is there a way to "hot wire" the fuel pump to make sure it is working fine? Most of the checks I have require the engine to be running.

I have had issues with the ignition module in the steering column in the past and have replaced it. I was wondering if there was something in that that may be preventing power from getting to the fuel pump as it would not crank the night before.
 

mirae1

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Reading through the forum I found a post where it talked about testing the new pump before installing by connecting it and turning on the ignition. I always thought this would damage the unit so didn't do it. My problem may have been a lot easier to diagnose had I done so. I don't wont to have to drop that tank again if I can avoid it.
 

mirae1

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I see no one has taken a stab at this yet. I haven't done much on it this week except some research. I have learned that I may not be looking at the right fuse. Based on the material I have my fuse is under the hood in the fuse block under the hood. However that fuse slot is blank. I can't seem to find the fuse for this circuit. Does any one know where the fuel pump fuse is located for the 1995 GMC Yukon? I will be doing some circuit testing to see if I at least have power on the high Amp side of the relay. The relay checks out as being good.
 

SteveC

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On the fuel rail, take the cap off and screw on a fuel pressure gauge onto the Schrader valve. Start the engine, you SHOULD have 50-55psi. I would bet your fuel pump went south, it is located in the fuel tank (thanks GM).
 

mirae1

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It was the fuel pump. When I initially changed it out I still couldn't get any fuel. After checking out all other possibilities I dropped my tank down far enough to pull the wiring harness so I could run down my problem. I found that I had cross wired a couple of the wires when I put the new connector on. Fixed the wiring mistake and all is well. So the original diagnosis of the fuel pump was correct just the idiot putting it in (me) didn't get it wire correctly. costing me a few hours of extra work trying to figure out my own mistake.
 

Mhzabbyann

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I'm having the same issue..i replaced the fuel pump. Well my biyfriend did. And I hope he didnt get the wires mixed up. The bigger line goes on the left side right? And the smaller line hooks up on the right?
 
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