My fuel mileage has been declining in last few months. I filled up yesterday & I am getting 11.5 MPG in town. I installed a fuel pressure guage last night & getting 7 psi @ idle, 5 psi cruising & drops to 4 psi when I get on it. Sounds like my lift pump is dying. What do you all think?

 

Just recently i did a fuel filter change on my new to me 01 ram, it would not start after, the lift pump was not working at all yet the truck was running fine up to that time. I was getting good fuel mileage (21 mpg cdn highway) truck was starting good even in very cold weather and running perfectly. These lift pumps seem to cause many different kinds of problems when they are on their way out, or in my case, none at all. I guess what i am saying is that poor fuel mileage does not automatically mean bad lift pump .<br> Maby the ait sensor? from what i have read here the dirtier it gets the more fuel that gets delivered to the engine because it thinks the engine is colder than it really is, which would explain a gradual decrease in mpg.<br><br> rob<br><br>

 

cummins specs say that the fuel pressure should neverm drop below 10. your lift pump is going

 

I just had mine checked and replaced at the dealership in Suffolk VA. The diesel tech said you shouldn't see under 10 @ idle. Mine was 9@ idle and I had dropped it to 5 - 3.5 @ WOT under a load. the truck had started to kind of whimp out towing the 5er up the mountains @ 5psi. I didn't notice any fuel mileage loss, but I knew it wasn't getting any better.
*NOTE*These lift pumps are covered under the 5year / 100,000mile warranty.

 

Marky Mark,<br>When was the last time you changed your fuel filter? I don't know where you are tapping into the fuel system to get your pressure, but I tapped mine after the fuel filter and thought I had a bad lift pump. I changed the fuel filter as a last resort before the dealer trip and my fuel pressure went up 6 psi all around .<br><br>Chris<br>

 

I think mine is going out too, possibly. Same bad mileage and sotp power is not as good. I dont have gauges, so I dont know. Wife's rig, she wouldn't look at it anyway. By the way her mvr looks, she doesnt look at the speedometer either : I'm taking to the dealer this week.

 

Here is the deal. Mileage is at 11.5 MPG. Installed fuel pressure guage. Tapped it post filter. Read 7 psi at idle. I decided to change the fuel filter to make sure that wasn't the problem. After installing a new fuel filter, the pressure is still 7 psi. I will call the dealer on Monday.

 

I called the dealer today. They said the lift pump is not covered under my powertrain warranty since I bought it used last November. I called Cummins West here in Eureka &amp; they have one in stock. Guess I will be putting it in this week since I need the truck this weekend. Anybody have instructions on how to install it?

 

Just look at it, Easy job, total of 5 bolts and 1 plug.<br>Crack the lines loose before taking mount nuts off.<br> Danny

 

Should I get the higher flow banjo bolts? Which are the best?

 

MM-<br>Check HERE for some info I reported on some bolts

 

Spark Chaser. I was in on that post also but didn't get around to getting them. I figured I had better get a fuel pressure guage hooked up to see if the lift pump was going bad before I installed the banjo bolts. I am glad I waited. Now I will get them. Thanks.

 

Mark,<br>You have over 100K? If not, the dealer is lying. The lift pump is covered under the CUMMINS 5 year/100K warranty. Don't let the dealer tell you otherwise. If they won't budge, find another dealer.<br>I understand the Cummins dealers will also replace it, and if I had a choice I'd rather have the Cummins dealer do it.<br><br>Chris

 

Got my sensors wrong, should have said iat not ait. lift pump is covered under the engine warranty, mine was replaced by the dealer and even covered the tow to the dealership ;D<br>Don't let them snow you, this item is covered.<br><br> rob

 

Thanks guys. I am thinking of calling the dealer back but I am leaning toward just doing it myself since I just ordered the high flow banjo bolts. Also, this is the only Dodge dealer within 150 miles.