Fuel pump problems... Or fuel pressure... I NEED HELP!

Filling up at a strange gas station? Sounds like you might have picked up a tank of crap gas. It only takes one, then you have to clean the entire system. Pull the fuel filter and see what comes out. With that many miles on it assuming it's on the original fuel pump, may as well change it (NOT WITH AN AIRTEX) while you're in there.

This is also a risk at a normally good gas station when you fill your tank at the same time the gas station tanks are being filled. If there's any crap in the main tank, it's going in your tank. It takes about a half hour or so for the tank crap to settle out enough to not matter. When I see the tanker truck, I move on to the next station.

So far as the vacuum issues, the engine must be running for there to be vacuum. Just cranking over won't do it.
 
Telco said:
Filling up at a strange gas station? Sounds like you might have picked up a tank of crap gas. It only takes one, then you have to clean the entire system. Pull the fuel filter and see what comes out. With that many miles on it assuming it's on the original fuel pump, may as well change it (NOT WITH AN AIRTEX) while you're in there.

This is also a risk at a normally good gas station when you fill your tank at the same time the gas station tanks are being filled. If there's any crap in the main tank, it's going in your tank. It takes about a half hour or so for the tank crap to settle out enough to not matter. When I see the tanker truck, I move on to the next station.

So far as the vacuum issues, the engine must be running for there to be vacuum. Just cranking over won't do it.
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It's a gas station I normally go too, one at Kroger grocery store. 93 octane also.
But now that you mention it, they were filling their tanks at the time -_-
I just replaced the fuel filter a month ago too -_-
If I clear out the fuel filter will that maybe fix the problem or how would I go about cleaning the entire system?

But the vacuum issue was there when the car was running too.
 
It's very hard to prove that you had bad gas from a specific gas station, but if you want to try...

It also just takes one bad tank to completely foul the filter.

The vacuum issue will be completely unrelated to this IMO, based on what you've posted.
 
Telco said:
It's very hard to prove that you had bad gas from a specific gas station, but if you want to try...

It also just takes one bad tank to completely foul the filter.

The vacuum issue will be completely unrelated to this IMO, based on what you've posted.
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Yeah I know what ya mean. But the fact I drove my car there, put 5/8ths of a tank of gas in there. And my car doesn't start after that. Kinda shows it was that gas station. IMO.

And I was thinking the same thing about the vacuum issue.

But I'm going to take of my fuel filter and drain it out and see what comes out. Maybe even buy a new one too.
 
I just took off my fuel filter, it was clear.
But I checked my fuses and my fuel pump fuse was blown. It's was a 15amp fuse. Replaced it with a 20amp, it was all I had.
I still don't hear my fuel pumps turn on.
Could it be the fuel pump relay or diode. How can I check them?
 
Trrrex92 said:
Thanks for making a smart comment..
I wasn't asking for help or anything....
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And I certainly wasn't trying to help you to not burn up your expensive REM. The LS is a returnless fuel system. Fuel pressure is regulated electronically. There is a transistor in the REM that controls the amount of power to the fuel pump to control pressure. That transistor is sized so that it is protected from damage by a 15 Amp fuse. A 20 Amp fuse may or may not be too much for that transistor to handle.

The 15 Amp fuse didn't just wear out. It blew because either there was a short, or more likely the fuel pump motor overloaded. It could have overloaded because of trash stuck in the impeller, or more likely because the bearings on the pump are failing. Either way, the fuse protected the most sensitive part of the fuel pump circuit, the transistor in the REM. (It also protects the wiring and the relay, but the transistor is most likely to be the first thing to go.)

Now, with that said, I will bow out of this thread as requested.
 
I took spare from my girlfriends car. It's a 15 amp now.
Either way my car still isn't starting and fuel pumps are still not turning on.
 
I appreciate the help! Just not a single comment in my lack of mechanical knowledge.
Should the relay still be good? What about the fuel pump diode?
Time to replace the pumps?
 
If you don't hear the fuel pump running when the key is on, and the fuse was blown, then replacing the fuel pump would be worth looking into. You can check the fuel quality while the pump is out.

If you aren't mechanically inclined though, it might be worth hiring out. There's things that must be done to avoid tearing parts up as well as specialized tools to do the job correctly. It's not hard work but it is easy to screw up, up to and including blowing yourself and your car up and burning your house down, if you don't know your way around a wrench.
 
I'm going to look into buying a used fuel pump. I know it's better to buy a new one but I can afford a 200 dollar fuel pump, compared to a 50-65 dollar used pump. And I know someone that can replace the pump for me. Hopefully this does the trick. I miss my LS :(
 
Also I can't find which wire at the fuel pump to use to see if I'm getting power at my fuel pump. Could someone help me out?
 
So was trying to figure out how to find out if my fuel pump was getting power. I couldn't. I tried to start my car multiple times. It would just crank and the fuel pump wouldn't turn on. I disconnected the fuel pump and then hooked it back up( I did this Afew days ago too) but this time my car started. Turned it off and it started again.
I need some advice on if I should replace the relay before replacing the pump. Or something else. What do u guys think.
 
My fuel pump quit on me also 3 weeks ago. checked the fuse in the compartment area and it was blown, I replaced it with a new one and still doesn't work, I checked the relay and it was good, then I tested the power line from the battery to the fuel pump and it registered on my multimeter tester that it was supplying 12 volts. So I checked the fuel pump, by disconnecting it from the battery power and I connected two alligator clips (+-) from a 9 volt battery to the fuel pump, still it doesn't turn on. I ended up buying a new pump only and not the whole assembly, when I got the new fuel pump, I did the same test using a 9 volt battery and it work, installed the pump and Bamn! one click the car came back to life.
 
Interesting. In the telecom world we have a fix action called exercising the jack. What happens is electricity passing across a junction made of two different metals will build up galvanic corrosion, which will open the circuit. The different metals are the metal inside the jack vs the metal the plug is made of. To clear the problem, you just unplug and plug the jack a few times. After this is done, the circuit can run clean for years. I guess it's possible that something similar happened here. Corrosion would make a partial open, forcing a larger than normal power draw in order to draw enough power to the fuel pump until the fuse blows. Once it gets bad enough to blow the fuse, it's not able to run anymore. I suppose you could just replug it a few more times, then button it up and see what happens. If this is indeed the cause you should have no further problems.

Or it could just be coincidence... either way, you should know within a month, and in the meantime you can be saving for a new fuel pump. Another possibility is you have a dead spot on the pump's motor, and you happened to hit the dead spot the last time you shut it off. This is a common failure mode on GM fuel pumps, which is really kind of a nice feature. When the fuel pump dies on a Chevy, you aren't stranded quite yet. You whack the fuel tank hard under where the pump is, then it'll start one more time and will usually run until you get home or to your repair shop. It usually only works once though, the next time you shut the engine off it won't start again.
 
Telco said:
Interesting. In the telecom world we have a fix action called exercising the jack. What happens is electricity passing across a junction made of two different metals will build up galvanic corrosion, which will open the circuit. The different metals are the metal inside the jack vs the metal the plug is made of. To clear the problem, you just unplug and plug the jack a few times. After this is done, the circuit can run clean for years. I guess it's possible that something similar happened here. Corrosion would make a partial open, forcing a larger than normal power draw in order to draw enough power to the fuel pump until the fuse blows. Once it gets bad enough to blow the fuse, it's not able to run anymore. I suppose you could just replug it a few more times, then button it up and see what happens. If this is indeed the cause you should have no further problems.

Or it could just be coincidence... either way, you should know within a month, and in the meantime you can be saving for a new fuel pump. Another possibility is you have a dead spot on the pump's motor, and you happened to hit the dead spot the last time you shut it off. This is a common failure mode on GM fuel pumps, which is really kind of a nice feature. When the fuel pump dies on a Chevy, you aren't stranded quite yet. You whack the fuel tank hard under where the pump is, then it'll start one more time and will usually run until you get home or to your repair shop. It usually only works once though, the next time you shut the engine off it won't start again.
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Definitely going to be saving money for a new pump(or whatever future repair)
Let's hope for the best!
 
Anyone know which pump (primary sending unit, or jet/transfer pump) contains the check valve on an 02 3.9. I noticed after turning the ignition off that the pressure drops to 0psi instantly. Also, I'm guessing it isn't but is it something that can be seperately replaced, or does the whole pump need to be replaced?

And to the OP, you can just replace the pump motor in the fuel pump with strainers for anywhere from $30-$75. I've been chasing a lean condition and my psi while running is in the low range (~35psi) and I'm planning on changing out my pump motor. Just want to fix the leak down after I turn the car off while I'm at it.
 
"Anyone know which pump (primary sending unit, or jet/transfer pump) contains the check valve on an 02 3.9. I noticed after turning the ignition off that the pressure drops to 0psi instantly. Also, I'm guessing it isn't but is it something that can be seperately replaced, or does the whole pump need to be replaced?"

Bump. Anyone?
 
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