HELP, Lift Pump Problem

[Mag]

My truck started missing today so I suspected the lift pump. When I bump the starter I can hear no sign that the pump is running. Is this normal for a lift pump failure or do I have a blown fuse somewhere? If so which fuse?

Thanks Greig

 

[Wally19]

lift pump

Greig,

I would be willing to bet that your lift pump is dead. I just replaced mine last night, and it did the exact same thing yours is doing. After I replaced it, it work just like it did when it was new. But I dont know for how long.



Jason

 

[Mag]

Jason, Thanks for the reply. When your pump went south would it still hum like it was trying to pump or was it silent?

 

[Mag]

I just checked for codes and got a P-1693

 

[Valkyrie99]

I just replaced mine about 2 weeks ago. It sounded fine when I bumped the starter but no pressure. I had just changed the fuel filter and went to prime the canister and heard lots of pump noise but no pressure. Truck ran fine before. Good luck on the repair.

 

[Bigsaint]

There is no fuse

There is no fuse that I know of, believe me I checked quite a bit when the first Mallory died, best I could locate was a relay for the VP44. Please, someone correct me if I'm wrong.



As it is very apparent that the dead lift pumps keep on a coming, I've decided to do something to help the members without a FP gauge. I have a bunch of spare fittings,braided line, etc. and a Jegs liquid filled 0-30 psi fuel pressure gauge (it's one of those small, 1 1/4" gauges with the 1/8NPT post fitting on the back). I'm going to put togther a temporary set up with about 6' of braided line, so that you can observe idle and WOT psi's. I'll include adpaters for the 98. 5 and 99's as well as the 2000 + years. Once I get it built, should be by this time next week if the planes keep flying, I'll put up a post and send the set up to the first needy member, who can then pass it on to the next member, so forth and so on.



Scott W.

 

[Mag]

You're a good man Scott. I just got back in from trying the truck and after cranking for 15 seconds it started. I still don't hear the transfer pump running so is it possible for the injector pump to prime the system?

 

[Bigsaint]

Greig, more than likely that the lift pump is not entirely dead and still providing some fuel to the VP44. The VP44 will draw fuel, but mine wouldn't draw enough to restart the truck after the pump stopped working. I bumped the starter several times, must have gotten the Mallory to spin a bit and provide some fuel, then I tried again and it started, but ran like crap.



Scott W.

 

[Mag]

Well I Guess I'm off to the dealer this morning to get the trasfer pump checked out.

 

[Mopar-muscle]

there isn't enough oomph in the VP44 to suck past the filter . never mind thru the filter , the dead pump and about 10 plus feet of fuel line .



make sure you pull any and all bombs ...

 

[Mag]

Well the lift pump was dead allright. The bad news is they won't be able to have it fixed until Monday or Tuesday. I can't believe they don't stock a spare pump or two with all the trouble there has been with them. MM thanks for the advice. Already done. Does anybody have an idea of what percentage of these pumps are failing?

 

[redneckdr]

pump

i added a pusher pump near the tank(and filter) to feed the oem pump, at about 5k miles. it'll be interesting to see if this prolongs the lift pump life. don't have my gauges on yet, so, can't tell about pressure. i know the truck will run with either pump alone... ... ..... sure made the filter change a breeze.

 

[DEZLPWR]

Mopar,

I disagree with what you said about the VP44 not being able to suck fuel from fuel tank & through a completely dead lift pump. There is enough vacuum (at least in my case there was) to pull fuel all the way w/o a lift pump working, although I am sure that it is hard on the VP44.

I had my lift pump tested at Cummins and they said that it was COMPLETELY dead. Tested fuel pressure at various RPM's was consistently 0. Mechanic said VP44 was doing all the work.

The funny thing was that the truck ran perfectly fine with no power loss etc. The only reason I knew that I had a bad lift pump was that I couldn't get the fuel system to prime after changing the fuel filter.



Go figure.....





Steve

 

[**ICEMAN**]

there is a fuel system relay in the box on the fender well. thought mine was dead the other week,,no sound of cycling when the switch was turned on. the relay was bad.

 

[Mag]

ICEMAN, I sure wish I would've known that when I was talking to the tech this morning. He never bothered to check the relay even tho I explained to him the pump wasn't making any noise at all. I asked him if it could be electrical. He just ignored me, hooked up his FP gauges and told me "Your pumps dead". While looking around under the hood I noticed a missing exhaust manifold bolt also, so you all might want to check them for torque. I had read about this problem on this site before but never bothered checking. I should have known better

 

[BigDaddy]

Exhaust Bolts

Mag,



Took 15K miles before the torque stabilized on my exhaust bolts.

 

[Mag]

My engine's serial number falls into the TSB mentioned on page 94 of the last TDR issue. When I asked the service manager about the manifold bolt retention strap mentioned in the TSB he said there was no strap, just different exhaust manifold bolts. Does anybody know if he's feeding me a line of B. S or are they using different bolts instead of a retention strap?

 

[BigDaddy]

Look’s like Straps to me!

From DodgeRam.org



Discussion:

This bulletin involves the installation of retention straps to cylinders I & 2 and to cylinders 5 & 6 exhaust manifold bolts.



Symptom/Condition:

Vehicles that are used for extended heavy trailer hauling purposes may experience a loss of exhaust manifold bolt torque. This condition may lead to exhaust gas blow-by past the exhaust manifold gasket(s) and even loss of exhaust manifold bolts.

A new exhaust manifold bolt retention strap has been released as a means of locking the outboard exhaust manifold bolts in place. This will prevent bolt rotation and torque loss during the thermal expansion and contraction cycles of the exhaust manifold.



Diagnosis:

1 . Inspect the exhaust manifold bolts and exhaust manifold gaskets.

2. If any exhaust manifold bolts or gaskets are missing or damaged, then replace or repair the necessary parts prior to performing this TSB.

3. If the exhaust manifold bolts are in place for cylinders 1, 2, 5, and 6, and there is no damage to the exhaust manifold gaskets, then perform the Repair Procedure.



Parts Required:

Qty. Part No. Description

1 05072387AAA Straps, Exhaust Manifold Bolt Retention (set of 4)



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[Ron Bissett]

Originally posted by Valkyrie99

I just replaced mine about 2 weeks ago. It sounded fine when I bumped the starter but no pressure. I had just changed the fuel filter and went to prime the canister and heard lots of pump noise but no pressure. Truck ran fine before. Good luck on the repair.

Inside the PDC under hood by Batt . Look at layout and discription of fuse and relay set up found on inside cover. Also by batt 2 fuseable links on black heavy wires. Ron in Louisville KY LOL.