Fossil Rock

I have a 2000 S-10 Blazer (2WD) 4.3 Vortec. Truck has run flawlessly for many years. One day it just would not start and I didn't have time to look into it (had to go to work). After getting home that afternoon, I discovered the fuel pump was not running. I started checking things like the fuses and relays. The fuses were all good, so I moved on to the relay. I found another relay with the same part number on it to test with. Before I swapped the relay, I wanted to ensure the test relay worked. The test relay was for the horn. So, I turn the key on and tooted the horn... it worked. I reached back in and turned the key off and the fuel pump started running. I turned the key back on and the pump still worked. I thought to myself "Wow, blowing the horn solves fuel pump problems" ...

Anyhoo, the truck ran fine for weeks and one day after work it did the same thing again, no fuel pump. First thing I did was to toot the horn, but that didn't work this time (I know that didn't fix it the first time). I towed the truck home a few days later and it's been sitting ever since. The fuel pump has started running once or twice since then, but not reliably enough to leave the driveway.

I went a borrowed an OBDII tester to see if there were any codes, but there were none. The SES light is on as well as the ABS light. I've pulled some of the wiring loose under the rear bumper (trailer lights) looking for something that goes to the fuel pump, but haven't found anything yet.

I've read there is supposed to be a lead somewhere that you can feed 12v to test the pump, but am unable to locate that as well.

I've stated the process to drop the tank and yank out the fuel pump, but stopped to ask others if they have had any similiar problems and if there is something else I can check before dropping the tank (which looks like it's going to be a big ordeal by myself).

If I haven't given enough information, please ask and I will try to supply whatever info is needed.

Thanks

quinnman105

I had the same type of problem. I was on my way home from my g/f's at the time truck died on highway while going 65mph. Then died 2 more time got it started but the last time it just cranked and cranked all relays were good they had to replace entire Fuel pump assy. That is about 400+

EvansBlue

Yeah it seems to be a fairly common problem. Most of the time, a truck with those symptoms ends up with a new fuel pump.

Fossil Rock

Well, I started the tank removal process (which I am taking pictures to share) and wondered if testing the pump in the tank would be a good idea. I have the tank lowered but not yet removed, enough to see and reach the top of the tank. One of the fuel lines leaked a little when it was pulled tight while lowering the tank. I raised it back up a bit to stop the leak.

What I'm wondering is, which of the connectors runs the pump, and can I apply 12v directly to the pump from here to see if it works properly?

Also read somewhere that the oil pressure sending unit is in the circuit, could this be an issue?

The next thing, I'm wondering is, how to disconnect the fuel lines. Not having a lot of room to work, how best would I disconnect the lines so I can finish lowering the tank?




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griff450

NOT SURE IF U FIXED YOUR PROBLEM YET BUT I HAVE A BETTER WAY TO DO IT, PUT YOU TANK BACK UP AND REMOVE YOUR BED, THEIR IS 4 BOLTS ON EACH SIDE AND 2 PEOPLE CAN CARRY THE BED BACK A FEW FEET TO CLEAR THE TANK, THIS GIVES YOU ALL THE ROOM YOU NEED TO WORK, AFTER THIS REMOVE YOUR FUEL LINES BY USING TWO WRENCHES, WHEN THEY ARE OFF TURN YOUR KEY SWITCH TO ON TO SEE I YOUR PUMP TURNS ON, IF IT DOES ITS NOT A RELAY OR FUSE, BUT EVEN THOUGH IT MAY PUMP DOESN'T MEAN ITS NOT THE PUMP, SO IF YOU GET THIS FAR REPLACE THE PUMP AND SOCK, ALSO THE FILTER WOULD BE A GOOD REPLACEMENT TO, JUST FOWARD OF THE TANK ON THE FRAME, IF THESE DONT FIX REPOST

griff450

OOPS, SORRY DIDNT SEE IT WAS A BLAZER SO DISREGARD MY ADVICE ON THE BED BUT STILL CHECK TO SEE IF THE PUMP WORKS OR NOT, WISH I HAD WORKED ON ONE TO TELL THE BEST WAY TO DO IT, SORRY

Fossil Rock

I went and bought the fuel line tool, but it won't fit around the "nipple" on the fuel pump*. The plastic between the "nipples" doesn't allow the tool to close completely. So I'm back to ground zero. I've looked from every direction possible and I can't find another way to disconnect the lines. The small screwdriver trick doesn't appear to be doable either due to the space around the "nipple".

* See the picture in my previous post.

I'm stumped.

nrgizrbny12

I'm having the same problem with my 2001 blazer. I have already dropped the tank and replaced the fuel pump and all but still no start.

On my tank there were 3 gas lines hooking it all together. There's a little plastic piece that you squeeze together and the lines should pop off. That might help you to drop the tank.

Do you know if there is a reset button or something on the Blazer like the Fords used to have? Everything else tested out positive on mine except that it won't start up even with the new fuel pump.

Let me know if things work for you and you find out an answer to my problem.

MDTAHOE

Alot of time the connect inside the unit melts ( where the wires come through the top of the assembly) Did you replace the pump and sock only or the hole unit?

MDTAHOE

Unless you unplug it inside you can change the pump and not even notice