Engine/Transmission (1998.5 - 2002) Another Lift Pump thread.......sorry but need advise

[arlan]

Hey group,



Here is my deal. I have a 1998. 5. It has 155,000 mile on it. It has been so long since I thought about my mods I couldn't remember all of them. I have a Diesel Dynamic 5 stage-fueling box. Can't remember what injectors. Can't remember what turbo change. A Bill Kondaly transmission with Smart Box transmission controller and lock-up converter. BD exhaust brake. A Gear Vendor unit. Four inch exhaust and other stuff. I installed and electric Auto Meter fuel pressure gauge in the truck many years ago. The pressure was low, can't remember the numbers back that far so I took it to Dodge. They said it only needed to have 3 to 5 PSI for fuel pressure but I told them it dropped below that at WOT so they changed it. I was better but not great. The truck is on its second lift pump the first was replaced under warranty so that was 6 or 7 years back. I am on my original VP44. It has had the Crank Shaft Position sensor replaced once under warranty. The truck has never been hard to start.



Oh, I just rejoined TDR after a year off. I seen my signature still exists so some of my mods were already listed.



Here are the numbers. On start up I had 3 psi cold at idle and it would drop to zero if I brought the rpm up. Once warm it idled at about 6. 5 psi, went down the freeway a 75 mph at 3 to 3. 5 psi and dropped to zero at WOT. I changed the fuel filter and those numbers remained the same. I added a Carter pump from NAPA. It is a nice $138. 00 pump with a bypass in the fuel line with a one-way valve. I guess it is set up that way so if it were to fail the OEM lift pump could pull fuel without having to pull it though the Carter. I get the new pump installed. I now have 13 psi at idle. The truck goes down the road at about 12 psi and drops to around 10 psi at WOT. I am happy with those numbers. :-laf The test was done on the way to the dump about 8 miles away and when I get to the dump I look down and I am sitting a 3-psi. I think WTF! #@$%!



I get home and put the truck on the lift and pinch off the line to the Carter. I start the truck and have ½ psi. I do all the checks of the line and one-way valve and every this is good. I take my Power Probe the up power to the Carter and I have about 5 psi. I power up the OEM lift pump and have ½ psi. The OEM has now died and the Carter pump is giving me slightly less pressure that I had before I put it on. I guess that is because it is forcing fuel through the dead lift pump.



So my question is. What do I do? Install another POS OEM lift pump? Install an after market lift pump. Install a FASS Fuel System pump or some other system that eliminates the OEM lift pump? If I knew how to do it I would just eliminate (by pass) the OEM pump and see what the Carter is giving me, but I don't know how to take the OEM out of the system.



I also am having the Dead Pedal thing going on but the codes are pointing to the TPS. I am getting a PO121 and PO122 code. I will address the Dead Peddle in another post.



The truck is getting old but I still love it when it is not messing with my head. I'm waiting to see what is in the future for Dodge. Really need a 4500 to be legal. I love the new Fords but I don't really want a V-8 diesel.



What to do, what to do!!!!!!



Thanks

Arlan

 

[Steve St.Laurent]

I can only tell you what I've done on my '98. 5 . I'm running a 7 psi carter back by the tank feeding the oem pump on the engine. I put the 7 psi carter on at 65,000 miles and I now have 220,000 miles on the truck and it's still there. I put on a new OEM pump at that same point and I had to replace it again at 190,000 miles - so the oem pump lasted 125,000 miles with the pusher there and the pusher has so far lasted 155,000 miles. Prior to 65,000 miles I put 4 OEM pumps on between 28,000 miles and 65,000 miles (bought it with 24,000 on it and that was before we knew about the lift pump issue). So for me running the dual pumps has worked great - I'm on my original VP44 btw (knocking on wood).

 

[arlan]

Hi Steve,



I remember you. I see your still here. I had a bit of time off. I wasn't looking for a new truck or any mods so I hadn't been on the forum for a long time. The dual pump thing doesn't sound to bad if the OEM will last awhile. Although I had been running the weak one for about 75,000 miles with those low to zero pressure readings and am on the original VP44 also. It should have died! Question. Will the carter keep pushing fuel throught the dead OEM pump without a problem until I get a new one should I go that route.



Arlan

 

[Steve St.Laurent]

It all depends on where the rotor was when it failed. With your fuel pressure readings as low as they are it's obviously seized right up and is causing a significant restriction. If it were me I'd replace it right away.

 

[arlan]

Crap, didn't want to hear that. I am heading out across the HOT desert right now. It is only an 80 mile round trip. Wish me luck. I called cummins, they can get one. I called dodge, the guy told me they only sell the in tank pump. What a laugh.