fuel pump problems

[Sy301]

Ok i installed my 255lph pump yesterday. Driving the truck it just suddenly died after about 4-5minutes of driving.

Went to start the truck back up and the FP isnt priming. The fuse is blown so i just pulled the radio fuse and put it in its place and the pump still doesnt prime.

So im kinda stumped. Ive searched the forum but there are a ton of pages on fuel pump problems and what not. Could it not be ground enough and the pump just took out the fuse and relay.

If so should I get a Racetronix Wiring Kit to just get away from the crummy GM wiring on the truck?

 

[MRKING]

Re: fuel pump problems

Clean the ground real good and double check the fuse . Still no workie , then check the wires at the fuel pump with a multi-meter . If you do have sufficient power and ground , then the fuel pump is dead . Just because its new doesnt mean it didnt go bad .

 

[Sy301]

Re: fuel pump problems

okie. Thanks Mike. Ill do that in the morning.

 

[QUICK STORM]

Re: fuel pump problems

most people use a larger amperage fuse, but my advice would be get the racetronix kit and not worry any more.

 

[TYRODD]

Re: fuel pump problems

Hook up a FP guage to the fuel rail just to make sure it isnt priming. Scrape off the grounds for the pump and coat 'em with grease .

Whats you oil pressure guage been doing? If its been bouncing around or just acts funny, R&R the oil pressure sensor. A dying sensor will pop the fuse and cut power to the ECM, FP, etc. giving you the same results.

15A fuse should be the max you use, anything bigger and you *could* have worse problems, like under hood fires :tdown: .

 

[SY2932]

Re: fuel pump problems

This will tell you if the fuel pump is dead or not:

"Applying 12 volts to fuel pump test connector to troubleshoot fuel pump or set fuel pressure with vacuum line still connected and motor off (note fuse for safety)."

Hook up a FP guage to the fuel rail just to make sure it isnt priming. Scrape off the grounds for the pump and coat 'em with grease .

Whats you oil pressure guage been doing? If its been bouncing around or just acts funny, R&R the oil pressure sensor. A dying sensor will pop the fuse and cut power to the ECM, FP, etc. giving you the same results.

15A fuse should be the max you use, anything bigger and you *could* have worse problems, like under hood fires :tdown: .

IMHO, grounds never get the attention that they deserve. When I did the fuel pump on my syclone six years ago, the ground wire was in pretty poor shape. It was even worse on my daily driven 1988 S10. The wires were still connected to the ring terminal until I gave the terminal a slight twist to check the condition on the wire stands themselves and they started to break off.

I am still running the same 10 amp ECMB fuse that was in my truck when I bought it over seven years ago. If you are constantly blowing fuses or have to "step up" to a 20 amp, you have electrical issues. My coworker is one of those folks who just keeps putting in a bigger fuse until it doesn't blow anymore :roll:. That is a fire waiting to happen...

 

[MRKING]

Re: fuel pump problems

I searched for that pic mike and couldnt find it . Although that wont tell you if the vehicle wiring has become faulty .Chances are it hasnt , but I figured while he was there checking the ground , the 100% way to rule out possible bad wiring is to check the lead at the fuel pump .

 

[SY2932]

Re: fuel pump problems

I searched for that pic mike and couldnt find it . Although that wont tell you if the vehicle wiring has become faulty .Chances are it hasnt , but I figured while he was there checking the ground , the 100% way to rule out possible bad wiring is to check the lead at the fuel pump .

If the url for a pic in one of my old posts is bad, you can *usually* find in my home page under my profile. When I use the search to find one of my old posts, I update the url for the pics when I come across it. Problem is there are so many...

 

[UR50SLO]

Re: fuel pump problems

You may have pinched the harness when you re-installed the tank... that's easy to do.. .also easy to install the lines under the top strap of the tank.. Definatly take the tank back down and re-check your wires and lines. Warbro's I've had in the past and present have never had a issue. But you just may have a bad one. Check everything else before assuming the pump.
There is a white wire (mentioned above) that will energize the pump with a Hot wire ran to it. About middle of the firewall if I remember right.
Good luck,Scott~

 

[Sy301]

Re: fuel pump problems

Well i put in a 15amp Fuse in the ecmb slot and switched the AC and FP relay which I read here

If you apply 12 volts to the fuel pump test connector (single connector that will be grey in color as mentioned by Wade, by the power distribution block on the firewall) and the pump runs, the fuel pump relay could be the problem. The AC relay and the fuel pump relay are both the same so, you can swap them to check.

Don't rule out a bad ground on the fuel sending unit either. Many folks had to "upgrade" to higher amperage 15 amp fuses after installing the high pressure Walbro pumps but, not me. I took the time to redo my ground wire when I put mine in four years ago. No problems since... HTH's

I took the grounds off and pulled out the handy dandy dremel and started grinding. I think i got it so i could probably see myself if it was actually big enough. Cleaned up the end to the ground and reinstalled it. Then went to go see if the pump would prime when i turned the key on and it did.

 

[SY2932]

Re: fuel pump problems

Well i put in a 15amp Fuse in the ecmb slot and switched the AC and FP relay which I read here



I took the grounds off and pulled out the handy dandy dremel and started grinding. I think i got it so i could probably see myself if it was actually big enough. Cleaned up the end to the ground and reinstalled it. Then went to go see if the pump would prime when i turned the key on and it did.

Glad to hear that you got it figured out . I would be lost without my Dremel 395 :lol:. Remember that the fuel pump test connector is connected DIRECTLY to the fuel pump. You could remove the ECMB fuse and disconnect the fuel pump relay and the pump will still run if it's good. Very easy to eliminate the fuel pump from the equation.

 

[TYRODD]

Re: fuel pump problems

Just some info that I discovered tonight...

I installed the Racetronix wiring kit in my Ty tonight, checked the pump voltage at the weatherpack connection:

(with cleaned up grounds and new walbro 255 pump)

Factory wiring: 13.2v

After racetronix install: 14.5v

Thats a difference of 1.3v!!! The pump even sounds different now.

I also have a voltmeter in the cigarette lighter. Prior to the Racetronics kit I had 14.4v at idle with the headlights off. After I had 14.6v.

Sounds like its doing its job to me!!!! :rock:

 

[Racetronix]

Re: fuel pump problems

Just some info that I discovered tonight...

I installed the Racetronix wiring kit in my Ty tonight, checked the pump voltage at the weatherpack connection:

(with cleaned up grounds and new walbro 255 pump)

Factory wiring: 13.2v

After racetronix install: 14.5v

Thats a difference of 1.3v!!! The pump even sounds different now.

I also have a voltmeter in the cigarette lighter. Prior to the Racetronics kit I had 14.4v at idle with the headlights off. After I had 14.6v.

Sounds like its doing its job to me!!!! :rock:

KeWL