Problems with fuel pump

Narkonus · September 19, 2003

The last few days i've been having trouble with my Yukon. It's stalled on me a couple times, been starting rough lately, and yesterday it wouldn't start at all. The engine was turning over, just not starting. I figured this had to be a problem with my fuel system. I changed the fuel filter, and when i pulled it out, it was full of black junk. Quite a bit more than i expected. That didn't help, it still woudn't start. Then i called the local auto parts store, and they suggested i check the fuel pump relay in the fuse box under the hood. I pulled it out, then put it back in. The Yukon started after that, so i figured i found the problem. For good measure, i bought a new relay and put it in. The truck drove fine yesterday after that, and all of this morning, but just a little while ago, i tried starting it, and it wouldn't start. I couldn't even hear the fuel pump humming. So, my question is, what could cause the fuel pump to work at certain times, but not at others. Do i need a new pump, or could it just be clogged (there was quite a bit of debris in the filter). Any suggestions would be helpful. Thanks alot.

k1500chevy97 · September 19, 2003

Maybe a loose electrical connection that drives the pump

Narkonus · September 19, 2003

I wonder if something was just loose too, but where would i look? Maybe right at the fuel pump, or somewhere along the way from the relay?

Bish · September 19, 2003

A clogged fuel filter can ruin a good fuel pump in no time. That's why I change the filter every 10K. Basically, when the filter plugs, the pump works overtime to push through filter. This can cause it to fail rather quickly. Only takes one bad tank of gas. One good test is to have someone turn the key and hit the bottom of the tank with a rubber mallet (during the ten or so seconds the pump runs before shutting off). If the pump fires up, it most likely needs a replacement. I've seen melted electrical connections to the pump. Mine had no obvious damage when I had mine replaced. Seems the NBS never last more than 100K. Mine went at 85K and that's with regular filter changes.

Narkonus · September 20, 2003

The pump is really loud when it does turn on. I noticed it when i bought the truck in July. I heard a whine everytime i turned the truck on and off. i could even hear it inside the truck, i just never knew what it was. The truck is a '97, and only has 58,000 miles, so i don't consider it to be too old. Anyone have any ideas about what might be wrong/causing this?

Bish · September 21, 2003

If it's loud, I'd recommend replacing it. Mine got loud about 10K before it failed at 85K.

MacADaYear · September 21, 2003

I would check the fuses agian first.

If they are all ok then you need to probe the Fuel Pump relay to see if its getting signal. It should turn on for about 2 seconds then off.

If you have no signal your problem is not the pump but the electronics goin to it.

Narkonus · September 26, 2003

OK, Today my Yukon wouldn't start at all. The engine would turn over, THEN the fuel pump would turn on, but the engine still wouldn't start. So i'm assuming i need to change the fuel pump. If someone has an idea about what this could be, let me know. But, the only thing is i'm not real sure how to do change the pump, so i was wondering if anyone here had a link to a site that could explain to me how to do it. Pictures would be a big help too, because if i knew what i was looking at it would be easier.