fuel pump

cavyboy23 · #1 10-03-2006, 02:06 PM

Ok im starting to get pissed i found the fuse box and changed the fuse still nothing, i just put a brand new fuel pump in almost 300 dollors i spent on it which is a rip off right there. Soo i put it in i get no power the truck has power but you cant even here the fuel pump turn on when u turn the key soo the only way to start it is to put gas in the throttle body bet then it stalls out cuz the gas isn't pumping

i checked the relays i checked the fuses and now what should i do everyone sais its a ground but what do i even do even if it is a ground? somebody please help i wanna get this thing on the road again

cavyboy23 · #2 10-03-2006, 07:09 PM

Man kno one can help me on this?

DelCoch · #3 10-04-2006, 02:24 AM

Will need to know what year, model, and make of vehicle you have and what engine??

cavyboy23 · #4 10-04-2006, 06:24 PM

1997 s10 4.3 v6 vortec 4x4

Blazerboy1287 · #5 10-04-2006, 08:04 PM

I don't know about on your car, but on the 95s there is a jumper wire you can run a positive connection to to make sure that the pump is running with the existing wiring. If it is there, it will be a red wire, with a black plastic connector on the end, on the driver's side of the engine compartment. It will not be connected to anything. To check if the ground is bad, run a wire from the positive terminal of the battery to that wire... if the pump turns on, then the problem is not the ground. If the pump does not turn on, then to fix a ground fault, you need some way to run a negative current (which is all the ground is on a car) to the pump. Try running a wire from the ground of the pump to a known good ground on the car. This would be somewhere you can measure using a voltmeter and a positive twelve volt power source. Let me know if there is that test wire on your car, however, and if so, if the pump turns on or not. Like i said, if the pump turns on, then your problems are elsewhere.

cavyboy23 · #6 10-05-2006, 11:03 AM

hey..yah mine has that wire i just tryed it and i still got nothing =/ what should i do now?

cavyboy23 · #7 10-05-2006, 01:16 PM

alright well it cant be the ground i dont think my dad said he ran a new ground to it that whole harness that plugs into the fuel pump isnt getting ANY power pleassssssssssssse help

alblogg · #8 10-05-2006, 01:28 PM

Quote:

Originally Posted by cavyboy23

alright well it cant be the ground i dont think my dad said he ran a new ground to it that whole harness that plugs into the fuel pump isnt getting ANY power pleassssssssssssse help

It could be your ignition switch.

Bassasasin · #9 10-05-2006, 01:46 PM

You say you dont hear it prime when you first turn it on.. it should buzz or run at first ignition turn on. . You should get a prime run for one second when you first turn your ignition on.

The source of fuel prime that is in the left rear corner of the engine compartment on a connector with a red wire.
Of course you still need a ground on the black wire at the fuel pump to work

However without the prime it should go to NORMAL circuits via the Fuel Pump relay switching after the start in the relay center after the prime.
HOWEVER.. you say you get nothing.. you need to check voltages and grounds.

Is it getting power there?

Good luck

cavyboy23 · #10 10-05-2006, 04:05 PM

Well we ran a new ground to the fuel pump a actuall good ground still nothing and then we got 3 new relays for the ones that ar ein the glove box and still nothign that was liek a waiste of 60 dollors right there still got nothing any other suggestions id hate to have to junk this truck over something this little

Bassasasin · #11 10-05-2006, 05:00 PM

How do the voltages look?
Can you put power to the pump and it runs?

Blazer SS · #12 10-05-2006, 06:11 PM

Check your TPS for proper operation. People don't realize that this controls a lot of items on our trucks.

DelCoch · #13 10-06-2006, 05:02 AM

Note: The red fuel pump test wire is located under the hood, on the drivers side inner fender, next to the black junction box. It will be a red wire with a black or gray end and won't be connected to anything - just hanging there. Make sure you get the right wire.

(A) Disconnect the wiring harness at the fuel pump connector at the gas tank.

(B) Apply a 20 amp fussed 12v supply to the red fuel pump test wire and leave it there while checking for current on the Grey wire at the fuel pump connector. (You can check for current with a test light or volt meter, but in any case make sure you have a good ground when testing)

(C) If test light is off (no Voltage present) – double check that you have a good ground for your test light. If test light is still off with a good ground - repair open circuit (broken wire) in Gray wire (Circuit 120).

(D) If test light is on – when using the blk/wht wire in the connector as a ground - re-connect the fuel pump connector and the fuel pump should run. If the fuel pump doesn't run – the problem is in the fuel pump.

Note: Some of the new fuel pumps run very quiet and you may have to check for fuel pressure at the test port (shrader valve - located to the rear of the intake on the drivers side) to see it pump is actually running or not. (Pressure must be above 60 psi for engine to start)

(E) If test light is off when using the blk/wht wire in the connector for a ground, but test light is on when using another ground, then the problem is an open circuit (is not making a good ground) in the blk/wht ground wire, (maybe a broken wire) - (Circuit 450).

-------------------------------------------------------------

Note: When you apply a 12V supply to the red fuel pump test wire it by-passes all other components in the fuel pump circuit.

If the fuel pump runs when applying 12V to the red fuel pump test wire, then check fuel pump pressure at shrader valve while pump is running. Pressure has to be above 60 psi for engine to start.

Report back with your findings and we can take you further. Good Luck.

Blazerboy1287 · #14 10-07-2006, 09:49 PM

Quote:

Originally Posted by DelCoch

Note: The red fuel pump test wire is located under the hood, on the drivers side inner fender, next to the black junction box. It will be a red wire with a black or gray end and won't be connected to anything - just hanging there. Make sure you get the right wire.

(A) Disconnect the wiring harness at the fuel pump connector at the gas tank.

(B) Apply a 20 amp fussed 12v supply to the red fuel pump test wire and leave it there while checking for current on the Grey wire at the fuel pump connector. (You can check for current with a test light or volt meter, but in any case make sure you have a good ground when testing)

(C) If test light is off (no Voltage present) – double check that you have a good ground for your test light. If test light is still off with a good ground - repair open circuit (broken wire) in Gray wire (Circuit 120).

(D) If test light is on – when using the blk/wht wire in the connector as a ground - re-connect the fuel pump connector and the fuel pump should run. If the fuel pump doesn't run – the problem is in the fuel pump.

Note: Some of the new fuel pumps run very quiet and you may have to check for fuel pressure at the test port (shrader valve - located to the rear of the intake on the drivers side) to see it pump is actually running or not. (Pressure must be above 60 psi for engine to start)

(E) If test light is off when using the blk/wht wire in the connector for a ground, but test light is on when using another ground, then the problem is an open circuit (is not making a good ground) in the blk/wht ground wire, (maybe a broken wire) - (Circuit 450).

-------------------------------------------------------------

Note: When you apply a 12V supply to the red fuel pump test wire it by-passes all other components in the fuel pump circuit.

If the fuel pump runs when applying 12V to the red fuel pump test wire, then check fuel pump pressure at shrader valve while pump is running. Pressure has to be above 60 psi for engine to start.

Report back with your findings and we can take you further. Good Luck.

Here's the English version of this for you:

Step 1: Attach a 12-volt Positive current to that red wire I mentioned earlier. Just to make sure, it should be about 12-gauge stranded, with red insulation, and a black or gray connector on the end. Leave this plugged in if you don't hear a pump running upon connecting this.

Step 2: Using a known good ground, test the voltage going to the gray connector at the fuel pump harness. If the voltage is good, then you have a DOA pump. If not, the proceed to step 3

Step 3: Check the ground of the fuel pump. If it is bad, fix it. If not, then proceed to step 4

Step 4: Check the gray wire going to the fuel pump. If nothing else is wrong, then this has to be the problem. Locate the break in the wire, and fix it. Your pump should then work.

Best of luck

DelCoch · #15 10-08-2006, 03:35 AM

Quote:

Originally Posted by Blazerboy1287

. . . Step 2: Using a known good ground, test the voltage going to the gray connector at the fuel pump harness. If the voltage is good, then you have a DOA pump. If not, the proceed to step 3

Step 3: Check the ground of the fuel pump. If it is bad, fix it. If not, then proceed to step 4 . . .

If you have proper voltage in Step 2 above, then do Step 3 before considering the fuel pump DOA.

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