Well, my fuel pressure is starting to fade. It was at 13 lbs. at idle, 11 cruising & 10 WOT when I installed the current pump in April of '03. Now it's 11 at idle, 9 cruising & 7 WOT. I've changed the fuel filter with no change afterwards. Is this pump going bad? I called Cummins and they said they have them in stock at $150.

 

Forgot to mention...I'm on my third lift pump now!

 

Sounds to me like it is time to think about a FASS system!!

 

you might want to verify the accuracy of your gauge.

 

MnTom, maybe the Fass will come sooner than I think. I've already spent over $300 for two pumps in the last 2 years so we'll see.

nitrousn, everytime I install a new pump the pressures are fine but seem to fall off within about a year. So, the guage seems to be Ok. Am I off base here?

 

If you really want to fix the problem you can do this:GET A TWELVE VALVE !! Just kidding!!!
Tom

 

MnTom, that's a good one! How would you like a nice '99 24 valve? I'll make you a great deal? All you have to do is change the lift pump every 5,000 miles! I'll even throw in the new lift pump I bought this afternoon.

On a serious note...I'm going to install the new one tomorrow morning. Hope it last this time. Otherwise I will look into something else to keep the pressure up.

 

UPDATE:

New pump is in. Pressure is at 14 idle, 12.5 cruise & 10 WOT. I'm going to get rid of the isolater inline with my fuel pressure gauge next (I have a early model tube-type Dipricol isolater) and go directly to the guage. Just have to figure out what I need to do it. Then I'm thinking about going with the Wildcat Max Flow kit.

 

MARK, the MAX FLOW KIT WILL SOLVE A LOT OF YOUR PROBLEMS WITH THE LP'S. Call ROD & get you one. They are cheaper than the LP's you keep buying.

 

How hard is the Max Flow kit to install?

 

It's not too bad. Just plan a full day, and take your time. I had to rest my back every once in awhile(drink a beer). Would have been a lot easier w/competant helper though. Take the intake horn,filter canister and canister mounting bracket off, then replace the lift pump, and install the maxflow. You will most likely need to crack an injector or 2 to get to fire up.

 

Thanks gamiller31. I'm leaving town for a week and will order the kit next week. Just since I installed the new lift pump my pressures have dropped a little. Now I see 13 lbs. at idle, 11.5 cruise & 9 WOT. It better not go any lower!!

 

Took me and my dad about 3-4 hours to do it. This is on a '99 too.

A couple tips:

While you have the LP off, install the max flow kit connectors that actually screws into the LP, otherwise it's a tight fit for a wrench in there. Might as well install the rubber fuel tube that plugs into the inlet side of the LP as well, just let the excess hang down and cut it to fit later while under the truck.

When you install the 90' connector on the outlet side of the LP pump have it pointed almost directly down , do a loop with the braided hose from the inlet side of the filter that has enough slack to not put to much pressure on the fitting, but keep that braided cord away from the brakelines and the dip stick stalk. If you don't the filter binds up on it making it more of a pain to change the fuel filter.