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Author Topic: No power to Fuel pump***  (Read 21139 times)

Offline waldosx5

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No power to Fuel pump***
« on: March 09, 2015, 05:57:35 pm »
I have a 1987 Chevy Pickup, 350 TBI.  This weekend I replaced the fuel pump and the sending unit.  After the install the truck ran great. I took it out for a ride that night with no problems.  Today(2 days later) I went to crank it and I could no hear the pump.  I checked and no gas was coming from injectors.  I went and bought a new relay to see it that was the problem.  If anyone has an idea throw it my way.  This is going to be my son's first truck and he bugging the crap out of me to fix it.  Thanks
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Offline VileZambonie

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Re: No power to Fuel pump***
« Reply #1 on: March 09, 2015, 06:20:38 pm »
Did you check the fuse? Check the associated wiring? If it put a jumper wire to the red pigtail on the fuel pump relay to B+ does it run?
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Offline waldosx5

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Re: No power to Fuel pump***
« Reply #2 on: March 09, 2015, 06:26:10 pm »
Thanks for the help. Where is the fuse located?
 and I hate to sound stupid but does B+ mean Positive Battery Terminal?
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #3 on: March 09, 2015, 06:28:22 pm »
Quote from: waldosx5 on March 09, 2015, 06:26:10 pm
and I hate to sound stupid but does B+ mean Positive Battery Terminal?
Yes
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Offline waldosx5

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Re: No power to Fuel pump***
« Reply #4 on: March 09, 2015, 06:41:03 pm »
Thanks again, I will try that and let you know the outcome but where is the fuse located for the fuel pump?
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #5 on: March 09, 2015, 07:46:23 pm »
afaik no "fuel pump fuse" but the ecm controls the fuel pump and if the ecm fuse either one is blown the pump wont work. but the main one that goes to the pump is "ecm B"
« Last Edit: March 09, 2015, 07:50:37 pm by Irish_Alley »
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Offline hatzie

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Re: No power to Fuel pump***
« Reply #6 on: March 09, 2015, 08:03:53 pm »
The fuse is marked ECM B.
A failed fuel pump oil pressure switch will kill fuel pump voltage.
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #7 on: March 09, 2015, 08:15:11 pm »
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Offline waldosx5

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Re: No power to Fuel pump***
« Reply #8 on: March 10, 2015, 01:39:27 pm »
ok here's what happened. I did the jumper test and nothing happened, I checked the fuses and they were all good.  I went to crank it and the battery was dead(the key was left on all night)so I charged it.  after charging I tried cranking it and it ran *great*. Now my question is,  How charged does the battery have to be to run the fuel pump.  It is a refurbished battery and it is about a year old, should I just break down and get a new one or do you think it may be something else?
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Offline flips87c30

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Re: No power to Fuel pump***
« Reply #9 on: March 10, 2015, 02:13:46 pm »
have you checked/cleaned all your ground wires? in my experience if the battery has any juice at all it will power the fuel sending unit.
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #10 on: March 11, 2015, 12:06:04 am »
Quote from: flips87c30 on March 10, 2015, 02:13:46 pm
have you checked/cleaned all your ground wires? in my experience if the battery has any juice at all it will power the fuel sending unit.
x2
i wouldnt think it would take too much energy to at least turn the pump. BUT it might not have been enough pressure to do anything.
do you hear the pump when you first turn the key "on"
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Offline waldosx5

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Re: No power to Fuel pump***
« Reply #11 on: March 11, 2015, 07:19:56 pm »
I do not hear the pump and when I checked the voltage going to the pump i got nothing.  I just bought a new relay and i cleaned all the grounds.  This is killing me!!!
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #12 on: March 11, 2015, 08:35:00 pm »
dual tanks?
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Offline waldosx5

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Re: No power to Fuel pump***
« Reply #13 on: March 11, 2015, 10:11:46 pm »
Yes but only one is hooked up (like that when I got it) the one tank bypasses the switch and is straight line to throttle bottle and the switch inside the cab is hard wired. It has been running for years like that.
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Offline Irish_Alley

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Re: No power to Fuel pump***
« Reply #14 on: March 11, 2015, 10:58:00 pm »
make sure that 12 volts are arriving at the fuel pump relay on the orange wire.
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When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes
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