First Aftermarket Lift Pump Question

[TowPro]

Its official, my 2nd lift pump is dead. This one only lasted 7000 miles



I install gauge, bump key and it reads 12psi, start truck and it reads 12psi, then drops to 2psi, but bounces back to 12psi a couple times then stays at 2psi.



As soon as I move it goes to 0, then I can suck it to vacuum when I push the go pedal hard. So I put a voltmeter on the pump, it stays at 13V all the time.



Sounds like this pressure relief spring is bad (same thing all the different revision pumps is still trying to fix).



Question:



I am going with a rear pusher install only (no front pump).



How do I bypass the front pump?



My concern is Warrantee. I am at 87K miles (it had 79,999 when the stealer put the last pump on) This time they said "your lift pump is out of warrantee, maybe if I (the dealer) talk to the zone rep we can do something for you, I will call you back" well that was a month ago, no call back so I guess warrantee is really over on this 7000 mile pump Not sure I want another 7K pump anyway.



If I bypass the factory pump and the Injector pump goes bad can the stealer say, "Your aftermarket pump caused this"? I now have a little "miss" at low RPM when I first let the clutch out that is new, maybe the new lift pump will correct this, but what if the Injector$ pump is really going bad?



How about if I install the new pump in the back, and leave the stock pump there, hooked up?



This stock pump bypass spring must be diverting pressure from the outlet to the inlet internally inside the factory pump in order to keep pressure at 12psi, now I feel the spring is just opening up allowing the lift pump to flow in a loop at 2psi. If I install the new pump pushing say 14psi, there isn’t any way the factory pump can divert it with its bad spring and cause a pressure drop. Then I will leave this hooked up this way until I feel safe the big pump is OK. (I drive the truck 6000 miles per year tops now that my daily driver is the VW TDI). This way if the big pump goes bad, the stock pump is still there (I could remove the rear pump if needed) for warrantee conserns.



What do you guys think? This would be no different then somebody running a 2-pump system with a front pump that has a bad pressure spring. I will be installing an 8psi switch to turn a dummy light on when the pressure drops hits around 8. I should have but the light system in last year when they put the new pump on, but after the first one lasted 80K miles I figured "why?"



I think I am going with the Aeromotive Street Rod Fuel Pump

unless somebody can point me to a better one in the "buck50 range" It has an internal regulator just like the factory pump.



I need to buy the pump this week, let the opinions fly quick!

 

[cscott]

I just dropped you a PM you have several options.

 

[abledog]

Shouldn't the second pump be covered under a seperate warrantee?



Terry

 

[LSMITH]

The lift pump is covered under the 100K mile engine warranty. The dealer is snowing you. I would make them put a new one on and spend my money on a pusher to support it.

 

[TowPro]

The lift pump is covered under different parts of the warrantee for different years. IN 1998, it was covered under the "HD Emissions Warrantee" which ends at 80K miles. Its in the owners manual that way, and thats what Several sources at Dodge have said.



But My only chance with Dodge is a dead lift pump will take out the front pump, the front pump is covered for 100,000 miles, I can reason with them "replace this pump now, or the lift pump later"



Maybe I will call 1-800-dodgedealerssuck (not correct number) tomorrow and see how much hell I can raise. :-{}

Originally posted by LSMITH

The lift pump is covered under the 100K mile engine warranty. The dealer is snowing you. I would make them put a new one on and spend my money on a pusher to support it.

 

[Lsfarm]

Mine Too

Tow Pro, my second lift pump died after only 3900 miles, the original pump at 14,500 miles. So with only 18,400 miles total on my truck I decided that a pusher pump was needed.



I installed a 7psi pump back at the tank, the same system and pump that Steve StLaurent did an article about.



I left the factory pump on the engine and fed it with the pusher pump. The factory pump works fine as long as the pusher pump is feeding it fuel under pressure. This seems to reinforce the common belief [and pump manufacturer's spec. ] that the factory pump isn't designed to draw fuel from a tank so far away.



So without the pusher pump, I had a running "0" pressure pump, but feed it with 7psi fuel, and it wakes up and runs the total pressure up to about 17-18psi, and it drops to about 16psi at WOT.



This has been working fine for the last 3000 miles. So I would leave the factory pump in place and running, just feed it with a pusher pump and see what happens. It worked for me.



Greg L

 

[Chipstien]

If you install a pusher pump and the injector pump goes out the dealer will not warrant the pump. If you are really worried about the warrantee on the injector pump then I suggest that you stick with stock till the warrantee runs out.

 

[TowPro]

Just got off the phone with the Dodge HQ, they stick with the story "its out of warrantee, we will not fix it"



I told them "the last one only lasted 7k miles, so you understand I am not going to replace it with a stock pump, what happins of the injecton pump goes bad?" they said "if the new pump fails and causes the injection pump to go out we will not warrantee the injection pump"



Anyway,

What size rubber fuel fuel line fits over the metal line when you cut it back by the tank? I need to know so I can get the correct size fittings for the new lift pump.

I will order it as soon as I have an answer (the truck is not with me at work, I ride a train to work)

 

[Bigsaint]

3/8" i. d. will fit over the hard line.



Scott W.

 

[TowPro]

Thanks Scott

Originally posted by Bigsaint

3/8" i. d. will fit over the hard line.



Scott W.

 

[tmacc]

TowPro,

The Carter 4601 ($80 from Summit) I installed is working just fine. It's only got about 3-4K on it, but it runs 15psi at idle 13-14 psi at cruise and never goes below 10. 5 psi at WOT. You can also get a Weber adapter from Summit and eliminate the steel line completely. I set it up so the pump can be changed in about 30 minutes if need be. PM me if you want the details of my install.

Tom

 

[otis]

Hey Tow Pro,

Isn't nice for DC to be so helpful after you buy an expensive truck from them and these Lift pumps are failing steady!!

 

[C1B1DIESEL]

I know if you buy a lift pump from cummins that it carrys a 6 month unlimited mile warranty.



You would think that DC would have same type warranty.



Go figure

 

[TowPro]

last 2 questions

Last Questions,



on my 98, which steel fuel line (top or bottom) as viewed on the frame rail in front of tank is the supply line?



In order to help from making a mess when I cut the line, has anybody tried to open that blue fitting at the lift pump, remove the fuel tank cap, and put about 5psi of air pressure back through the fuel lines to blow the lines clear (and prevent the siphon when I cut the line)?

 

[Lsfarm]

The lower line

TowPro, the lower of the two lines is the supply line, and it is slightly larger in diameter than the return line.



I did blow the line out like you suggest, and got only a little fuel out of the line when I cut it.



Be carefull when bending the fuel lines, they are not soft steel, and kink easily.



Hope this helps, Greg L