Lift pump on its way out?

[Slightly Modified]

I bought a mechanical guage on Friday to check my fuel pressure since I have never checked it. It read around seven and half psi post filter at idle, and 3-4psi at WOT. Just cruising it hangs around 5psi. Is it on its way out? I have never checked it until now and the truck has 70,000 on it now so I have no previous numbers to compare these to. What is the minimum DC requires to replace the pump under warranty? Also, how do I update my sig. , I put a BHAF on this weekend also and wanted to add it to my list of goodies. Man that thing is HUGE!

 

[tragicwagon]

Slightly Modified





Im not sure what DC requires before they replace it but those #s seem pretty low,hopefully someone else will chime in with the specs,I think mine is bad too. For your sig click on user cp then click on edit profile then type in what you want then click submitt.

 

[tobaccogrower]

i think mine is on it's way out too... ...

i have a electric guage from genoes. on my way down to flordia it started acting funny: it would read 11psi then swing down to 2psi and bounce around anywhere in between. it did this for about 1000miles and then went back to a solid 8psi @ 80mph. the way it acted i figured the sending unit was going bad(although it's not even 1 year old) it's been almost i month since it has happned untill yesterday. doing it again. when the guage goes batty, there is no stumble or hesitation in the engine. any ideas???? TIA... james

 

[BigDaddy]

Slightly Modified,



3–4 psi at WOT with an EZ seems normal. However, 5 psi at cruising (when I was running with my VA I would see 10 psi cruising @ 75 MPH consistently) and 7 1/2 psi at idle (Post Filter) is low. Should be 10 psi (Pre-Filter) at idle with a maximum differential of 5 psi pre/post filter.



Try to get a test gauge and check your pre and post filter pressures at idle. This will check the accuracy of your fuel pressure installation and provide you with pre-filter pressure. If you cannot get a test gauge, replace the fuel filter and your post filter pressure should be about 10 psi. If it is not, replace that lift pump.



James,



Hey there stranger You to may want to check your pressures with a test gauge. I remember at one time Geno’s gauge did have some bad sending units. Is yours connected remotely? If not, this may also attribute to a failing sender unit.

 

[Lsfarm]

Yes, they are both going bad

Sorry to give you the bad, but inevitable news: those pumps are going bad.



The pressure spec from DC is no less than 8psi at WOT. Also, there is a spec for no less than 10psi at idle.



My original pump was rock steady with 15psi@ idle, 14psi down the road, and 12psi at WOT. Then it started to give jumpy readings, and be slow to build pressure. Pretty soon it would not develope over 6psi. This one was warranteed by the dealer at 14. 5K miles.



The replacement pump just started to do the same at 18,400 miles. Only 3900 miles later!!



I installed a pusher pump [Carter 7psi pusher] and now with the help of the pusher pump, the total pressure is above 16psi, about 15psi @ WOT.



I believe that an additional pump, [or the only pump] must be down by the fuel tank. Pumps like to push, not to suck.



Hope this helps, Greg L

 

[Ramafid]

The lift pump seems weak to me. I'm at 14-14. 5 at idle, 12-12. 5 at 70mph, and 8-9 at WOT. Fuel pressure that jumps around is not a good sign.

 

[WyoJim]

Slightly Modified... . I would change my fuel filter as Big Daddy suggested and see what the readings are then. If they are still that low I would get a replacement from a Cummins dealer and carry it with me at least. They will want your engine number to sell you the correct one, about $140. You will find the engine number down between the injector pump and the engine block as you lean over the radiator from the front.



RAMHEAD3437... I too have a Westach from Geno's that did that same thing you describe. After about a day of that BS it settled down and has acted normal ever since. That was 9 months ago.

 

[chuck3]

I don't know about other places, but here the dealers are willing to replce the pumps at anything below 10 psi at cruse or below 8 psi at WOT, or at least that what a couple told me over the phone. I have 12 psi at idle and drops to 5 at wot and about 9 psi at 65 mph. They told me to bring it in. I'm waiting for Briar's test gauge to double check these numbers and then take it in.

 

[rcaldwel]

Lift Pump pressures

Just got mine replaced two weeks ago. I had installed a Westech FP gauge(TRD expert members strongly advise putting in gauges) and noticed that my pressures were low(idle 8 PSI, WOT 4 PSI). Had dealer check it out and they gave me no hassles saying minimum at idle should not be less than 10 PSI and at WOT not less than 8 PSI. Have 94000 on truck all covered under engine warranty. New pump shows 18 PSI at idle and 14 PSI at WOT. Without the FP gauge I was running blind. The experts here at TDR really stress gauges and now I know why.



Bob Caldwell

 

[BigDaddy]

The pressure spec from DC is no less than 8psi at WOT.

Lsfarm,



Can you tell us where you found this? TSB, FSM, etc.



TIA

 

[Mopar-muscle]

slightly , yours is on the way out ...



james , what pump do you have and where is it mounted ?



its probably getting ready to go .



my HP carter mounted on the engine died a week ago , 1 yr and 32k miles , i carry the factory pump as a spare .



time to move it back to the tank and put the factory pump back on the engine as a just in case backup ...

 

[Steve St.Laurent]

The 8 PSI at WOT spec is from the DC STAR hotline (the place the dealers call) and is a fairly recent change. The only spec previous to this was 10 psi at idle. It was posted on here by a member that works at a dealer and he got it directly from STAR.

 

[BigDaddy]

Steve,



Thanks for the info



Sure would be nice if we could get that in writing. Would save :-{} with the dealer.

 

[rcaldwel]

FP - Factory Manual

I don't have my factory manual in front of me. However, I recall when I installed my FP gauge that in the section on testing the Lift Pump it is stated that the idle PSI should be at least 10 PSI. If someone has access to those, maybe they could look it up and post the section, page etc.



Bob Caldwell

 

[me4osu]

Boy, was I lucky.

I was changing the fuel filter this weekend. When I bumped the starter to top off the filter, nothing. I bumped about ten times before I gave up and concluded that the lift pump was bad.



I am lucky in that the darn thing didn't leave me kicking rocks on the side of the road!!



My local Dodge dealer (DOWELL MOTORS in Sealy, Tx. ) covered the tow, new lift pump and two re-flashes under warranty. Also, I didn't even remove the EZ!!



I am now quite interested in the best fuel pressure gauge set up. I saw a post a while back where someone used the Stewart Warner sender & gauge. Does anyone have them? Do they work OK?

 

[Steve St.Laurent]

I've had a Stewart Warner fuel pressure gauge on my truck for over 2 years and have had no problems with it at all. See this thread for info on where I bought it from and install, etc - https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=6113 .



-Steve

 

[me4osu]

Thanks Steve

I will be doing that VERY soon. I forgot that was your thread I saw about the SW gauges. Thanks again.

 

[Amianthus]

Welp, add me to the list of failed lift pumps. Funny thing, I ordered my pusher pump on Friday. Hmmm. I'll keep you guys posted on my progress. Good news though, is that I found the reason for my stumbling. Now I just have to fix it. I can't wait.

 

[Chipstien]

Hmmmm,what do you think?

I installed my FP guage a week ago and idle was at 12, freeway at 9, and WOT at 3 to 4. Is this bad or can I wait till I can afford a carter pump to put at the tank in conjunction with the factory pump. Why can't DC put these at the tank. #@$%! I don't want to go to the dealer. :{ Probably just do it myself.

 

[Amianthus]

Ummm, hate to break this to ya...

Chipstein,



That's the same thing my pump has been doing for quite a while. It's on it's way out. Sorry.