Engine/Transmission (1998.5 - 2002) lift pump hot wire

[lonewolf1]

i have lift pump that when i cycle the key it runs for 2 seconds then stops... truck wont start. . tryed a new pump and new cps. same thing it will start if i cycle the key for 5 to 10 min and have 15 psi... what i would like to know is can i put 12 volts from the swicth to the pump where it works all the time any info would be great and lots of help. . i need this truck for work everyday and now has me so ****** i want to burn it

 

[Cummins724]

i have lift pump that when i cycle the key it runs for 2 seconds then stops... truck wont start. . tryed a new pump and new cps. same thing it will start if i cycle the key for 5 to 10 min and have 15 psi... what i would like to know is can i put 12 volts from the swicth to the pump where it works all the time any info would be great and lots of help. . i need this truck for work everyday and now has me so ****** i want to burn it

You can hook it to 12v, but make sure that you disconnect the stock harness from the pump first or you will "backfeed" 12v to your computer.

 

[AKAMAC]

Are you bumping the starter or just turning the key on?

The LP should run for 20~30 seconds after you bump the starter and leave the key in the on position.

It sounds like you have an air leak in your HP fuel system.

 

[mhenon]

i have lift pump that when i cycle the key it runs for 2 seconds then stops... truck wont start. . tryed a new pump and new cps. same thing it will start if i cycle the key for 5 to 10 min and have 15 psi... what i would like to know is can i put 12 volts from the swicth to the pump where it works all the time any info would be great and lots of help. . i need this truck for work everyday and now has me so ****** i want to burn it

Cycle the key on and off three times. . leaving it on the last time. You can read the codes off the odometer. Let us know what codes are showing and maybe someone can help out.

Mike

 

[pgleavitt]

With mine if I bump the engine with the starter and then leave the key in the run position the pump will run for 30 seconds. I do this 4-5 times when I change my fuel filter. It then starts right up.

 

[WBodine]

You might need to have a look at the thread I recently posted. .

( START AND DIEING PLOBLEM ) My truck was doing a similar problem

with the fuel pump acting a fool thought it might be my CPS ended up being pluged fuel screen... Oo.

 

[ABritt]

lift pump

replace lift pump,replace with 1/2 big line kit. code1693/216. truck lose power

going small hill.

 

[timbo]

sounds like air getting in the system. this happens on the suction side of the pump. maybe the screen is clogged in the tank causing high vacuum on the suction side. sometimes it hard to find leaks on the suction side. on hydraulic systems i usaully coat the fittings (one at a time) with a nice heavy grease. this keeps the air from entering if its a bad connection. Hope you find the problem!

 

[Makensmoke]

lonewolf keep in mind my truck and many others have ran for many miles with a bad LP alltogether. The HP pump will draft on its own if need be, as long as all is in good shape.

I'd lean twards a leak or faulty HP side, it doesn't cost anything to confirm that fuel can get to the LP freely first though. Maybe purge some air down the line twards the tank. Could temp clean up the line to help you diagnose.



Good luck, I can understand your frustration right now, i've been there.

 

[lonewolf1]

the pump will run for 2 to 3 clicks and stops after bumping the motor over... . will do this from 10 to 30 times then it will come on and have 15psi. . also no codes or engine lights p done ecu p done and i do have the big line and frame rail mounted at the tank lift pump help????????

 

[Cummins724]

the pump will run for 2 to 3 clicks and stops after bumping the motor over... . will do this from 10 to 30 times then it will come on and have 15psi. . also no codes or engine lights p done ecu p done and i do have the big line and frame rail mounted at the tank lift pump help????????

I'd try another pump... . maybe get a holley blue & mount it where the stocker is on the frame. Maybe you have a bad fuel pump relay... . locate it in the fuse box & switch it with the fog lamp relay to test it. It may be clicking on/off & not letting the pump build pressure.

 

[Makensmoke]

So you do have an aftermarket lift pump setup installed? If so is it different from stock as to not let the injection pump suck thru it if it (aftermarket lift pump) was to quit?

I agree with you Cummins as to easily swap relays, you should also attempt to confirm voltage at the lift pump when its not supplying pressure but should be.



Besides you not having consistant pressure your injection pump is still not sucking. Do you have the air out of the lines etc. so if you did have fuel available to the injection pump it would fire?