Archived replaced lift pump - now doesn't run well

[JRS]

My primer button started leaking, so I replaced the fuel transfer pump. I got the truck started, but it ran rough and then finally smoothed out after driving it. I went out this morning to start the truck and it had lost it's prime and wouldn't start. After work today I checked the tightness of all my connections, but didn't find anything loose. I bled the air again and got the truck started. I drove down the street. maybe a 1/8th of a mile and the truck ran out of power and died. Now it won't start. any help would be greatly appreciated.

 

[MCharlebois]

you need to fill out your profile so people know what year truck is ect-2k and up check your codes-flip switch 3 times-watch odometer

 

[bmoeller]

It is in his profile, just not his sig. He has a '97 2500.



I haven't had mine off yet, so this a guess. Do the fittings use a small rubber seal on them? If they do, there could be one that got pinched or cut. I know John Deere uses that type of seal on their later model tractors. I normally use the new seals that come with the pre-filter on some of the tractors, instead of re-using them.



Have you replaced the rubber fuel return lines yet? Sometimes they let in air, but don't leak fuel. Maybe bumped it when changing the pump and it cracked if it is dried out.

 

[JRS]

yes, the hoses have been replaced. There was one rubber seal in the fitting that threaded into the top of the pre-filter. I replaced it when I replaced the pump. It was not included with the pump from Cummins. (Niether were the two gaskets required to seal the pump body against the engine block) I can't find a leak anywhere.

 

[Joe G.]

If you still have the old pump try replacing the O-ring on the push button. Then install that pump in place of the new one and see if the problem changes. The only thing that can leak on the push button is the O-ring unless the plastic is cracked or something like that.



It sounds like there is a suction air leak somewhere.

 

[JRS]

The truck will now run for about 2 minutes, then dies and won't start again.

 

[JRS]

I noticed that with the new transfer pump I kept getting bubbles out of the vent when I pressed the button. so I spent an hour and put the old transfer pump back on the truck. wow, clean fuel now comes out of the vent when I press the button. BUT, the truck still only runs about two minutes, enough to drain the filter housing.

 

[Parks]

I just had the same exact problem with my 97. I changed the lift pump and checked all the hoses but I still could not get the truck to run. I started checking further down and I noticed that the quick connects had fuel leaking around the connectors and also I had several pinholes in my fuel line from were the lines had rubbed against the transmission.

I went to Dodge to try and get a new fuel line but they were discontinued.

So, I went to my local auto supply and bought some really good 3/8 fuel line and some hose clamps and cut off the old fuel line and replaced it with the new one. I also put 3/4" split loom over the new line to help protect it from rubbing. Now my truck runs better than it ever has.



If you do not have any fuel leaks you may have a clogged fuel pick up in the tank.

 

[JRS]

The hose seemed to be ok, but I did replace the quick disconnect clamps. The truck was running fine before I changed out the pump. Just drove it across country and back hauling a 9,000 lb. race car trailer. The only reason I replaced it was because it was weeping at the button and the parts counter guy at Cummins convinced me to replace the whole pump. I figured it was preventative maintenance, since I have 130,000 miles on the truck and it was time for the transfer to pump to go anyway. Seems like I opened Pandora's box! I think I am going to try bleeding at the injectors tonight. For some reason it uses up all the fuel in the filter housing and then quits.

 

[B.G. Smith]

If you are emptying the fuel filter, then the fuel must not be making the trip through the new pump?? Maybe justy the primer part is working?? Is it possible to get the actuating lever of the pump on the wrong side of the cam lobe? Maybe just a bad pump out of the box? bg

 

[JRS]

yeah, I thought about BOB and thought he might had visited me. But then I put the old pump back on. it was working fine before, just weeping past the plunger. Now the old pump is acting the same as the new one. (pumping out the filter housing)

 

[akline]

Once the truck is running there should not be any need to bleed the injectors. Any air will work out as long as the truck keeps running. Take a gallon jug full of diesel and run a hose from the supply side of the lift pump to the jug and see if it will keep running until the jug is empty. If it does, the problem might be in the tank. It takes a fair amount of air being pulled in somewhere from a suction leak to cause the truck to die completely.

 

[JRS]

truck won't start at all now, plus I have worn down my batteries for the night. I called Cummins, but they are backed up for four days. Looks like the Dodge dealer for me.

 

[AKAMAC]

I know this sounds simple, but it might save you the trip.

Connect a fuel line about 8' long to fuel inlet of pump and the other end in 5 gallon can, prime and start. Will tell you if the supply line from tank is leaking. Be sure to put a piece of cheese cloth on the can side of hose and secure it with a zip-tie.

 

[JRS]

thanks, but I tried this tonight. no luck. The truck won't even start now, hooked up to the can or the gas tank. Then again my batteries were about gone and it gets dark quickly. I've been messing with this for four nights now and it all started under the guise of preventative maintanence on a Sunday afternoon. I have a pregnant wife who would like to visit with me and show me sonograms of our first baby. some things are more important than me working on my truck. Will take it to the Dodge dealer on Friday. I'm sure it's something simple. Thanks to everyone and all their ideas. I'm going to spend some time with my wife and look at some pictures... .

 

[britannic]

Did you try removing the pump and checking if it actually works operated by hand? Did it suck fuel from the gas can?

 

[JRS]

Yes. the check valves worked on both pumps.

 

[mikel]

Isn't there some kind of push rod in there to operate the pump off a lobe on the camshaft? Is that back how it is supposed to go?



If not then that would explain why the old one (that worked fine, just leaked) is now "acting exactly like the new one"



This would also explain why it only runs until the fuel canister gets empty.



Good Luck,

Mike

 

[JRS]

Good point on the pump. I followed the Dodge service manual and rolled the engine over by hand so that the lobe on the cam shaft was at it's low point.

 

[JRS]

Will change out the molded rubber hose between the pre-filter housing and the pump itself tonight. I have already replaced the squeeze type factory clamps with some screw type clamps.