Justin

1999 Chevy Blazer Fuel Pump Problem!

16 posts in this topic

Ok I will try to make this short. I just replaced my fuel pump on a 99 s10 blazer with a 4.3 vortec. Because the fuel gauge did not work, but the pump was good all I really needed was a sending unit but I got a deal on the whole thing. Before I replaced it I had no problem with it at all. But after replacing it today I was driving and came to a stop light when I gave it gas to take off it felt like It wasnt getting fuel. And then it finally died so I pulled in a parking lot to figure it out. I tried starting it but it wouldnt start so I let it sit for a few minutes and then tried to start it again which it did and ran fine but then it died after a few minutes. So long story short I have found out that the relay is good and also the pump and ground is good. When I trun the key on the pump only primes some times not all the time like it should like their is a short. I cant figure this at for nothing. Any help would be great! Sorry for the long post.

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Check your fuel filter....it may have some crap in it making it seem like its a problem with the pump...it's on the drivers side frame rail about mid cab. also, If there is already enough line pressure, the pump will not need to prime every time you turn the key on.

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I have droped the tank and their is no fuel in the line so it should prime everytime. And no it wont crank.

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sounds like you have a bad pump.

what brand of fuel pump did you buy?

bosch pumps are crap for gm vehicles.

i would go with a delphi,or the ac delco pumps.

Edited by badasschevy

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The pump is good I have benched tested it and work like new. So its not the pump. I hooked the old one up which worked when benched and when I turn the key on it wont do nothing and the pump sint hooked to the fuel lines so its not primed which means it should come on. So it has to be something else maybe a sensore or something going out is their such a thin? the relay is good so it has to be something else. someone told me a reset switch what is that? Thanks for the replys.

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have you checked for power back at the connections at the pump?checked the fuse?

check the harness for any breaks or corrosion, also might be a good idea to replace

it anyway while you have access.

heres what the harness looks like.

http://www.napaonline.com/MasterPages/NOLM...+Wiring+Harness

Edited by badasschevy

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Mine looks a little different but nothing is wrong with it. I am going to check from the relay back to the harness and also there is alot of corosion on the fuse between the battery and the fuse box under the hood so i will clean that up Also going to check and change the grounds.

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Ok grounds are clean and ran a extra off the fuel pump harness. Then went the fuse box under the hood and started to mess with it and niticed that when moved the lights cutt on and off what the hell?! So I looked for anything loose but nothing. Any Ideas?

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Ok it is running again! I got home today and decided to reset the ecu and I fixed the connection on the interior/battery fuse. And I also changed the 5v ground on the fuel pump housing. Then gave it a try and it started and has not died yet so hopefully it is fixed.

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