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Truck wont start...some advice..need to get her running!

dsmd58

dsmd58

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Ok, so I go out to the burb this morning and she cranks but doesnt turn over...

I pulled a plug and I am getting spark (got zapped doing so cause my stupid neighbor cranked it before I told him so!)

Went to the fuel filter on the engine side, disconnected it...cranked again but fuel only came from the engine side down my arms. Nothing came out from the tank side...

Could this be the pump or just the filter? Whats the quickest way to tell if its the pump? Or any other ideas?
 
I actually tried that but heard nothing....im also not sure what to listen for, though.

I do hear the pump relay in the engine compartment click when it goes to run....hmm pump maybe?
 
will check...looks like there is two wires running to the pump via a connector on the frame, and a separate ground wire that runs and bolts to the fram

what is the best way to actually check the fuel filter? I just want to make sure before I drop a tank in the middle of my driveway...lol
 
Remove the input and output lines from the filter and turn the key to RUN. That will let you know without a doubt if the pump is working.
If it is then re-install the input side of the fuel filter but not the output side.
Move the key to RUN again and see if any fuel goes through the filter.
 
duh....gonna do that now. check back in a few! Thanks for the help brotha!
 
ok so disconnected the fuel filter completely, set the key to RUN and nothing out of the hard line on the pump side. checked ground...looks ok.

the pump relay clicks on the firewall...is there anything else that would keep the pump from running then?
 
yes, but there are a total of three wires...

one to ground (bolted to frame)

one pink

one grey

what should each of them read? (they are on the tank side of the connector - when it hits the connector and runs up the frame they are different colors)
 
One will go to the sender the other is for the pump. I would disconnect the connector and check both if them.
You could also follow the wire from the bottom of the relay to verify which color is for what.

I think the pink is for the sender.
 
ok will check for 12v....if im right isnt there something that tells the pump to turn on? is it the ign module?
 
I'll let someone else answer that.

I don't have my schematics handy, and every time I try to explain it all from memory I screw it up......Then Dorian corrects me.:haha: He seems to know more about the fuel pump system than anyone.
 
Well, thanks for the kind words. :)

On initial prime, once the pump primes the system, there won't be 12V on the line, so it's harder to test based on priming. I'd start by leaving your filter disconnected like you did, and use the red pigtail at the fuel pump relay. That is to bypass the relay and should force the pump to run. I believe you provide it 12V, but I've never done this, so do a quick search, it's been covered by others.
 
ok cool, so i bypassed the relay and only one wire did not read 12V PINK.

I did it like this

1 - bypassed the relay by jumping 12v to the connector at firewall
2 - Turn truck to run position
3 - Pink did not read 12v...shouldnt they both read 12v?

solutions? i just went out and bought a new pump. i dont want to start to tear this bitch apart just to find out it was something else...
 
No, one of the connector wires is your fuel gauge sending wire.

If you put power to the relay "externally" it probably doesn't matter whether the truck is off or in run, since the run is only switching power.

The connector you are talking about, that IS the spare pigtail for testing, right?
 
Yes its the pigtailed connector at the relay under the hood. So only one of those wires at the pump should read 12V then if I am understanding correctly....

So after jumping the connector I still dont hear a fuel pump running....so I guess that means switch it out right?
 
Check for the voltage down near the pump after you jump the relay. It would suck to swap out the pump if the problem was only a bad ground connection or a bad hot wire.
 
As long as your 12V wire to the fuel pump itself is good, (as far as you can test, which is the tank connector) and the pump is grounded, yes. Check your tank wiring before you drop it. :)
 
thanks dorian....gonna see what i come up with.
 
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