Thread: 03 cummins diesel

I've heard that Smarty TNT or something like that is a best for the 24 valve. Keep in mind that your VP44 IP is prone to fuel starvation-led death, so a lift pump upgrade would be advised.

Didnt know they where prone for that, do I just need more pump presure?? As I can find an after market pump to feed sufficient pressure...any suggestions?? Im new to the electronic side of things...If it was mechanical Id be ALL over it (used to play with my aunt 98 cummins last of the mechanical ones) and then i got a cousin the dabbles in diesel and theirs to much electronics for me to play with this truck...

Originally Posted by searstractorfan

Didnt know they where prone for that, do I just need more pump presure?? As I can find an after market pump to feed sufficient pressure...any suggestions?? Im new to the electronic side of things...If it was mechanical Id be ALL over it (used to play with my aunt 98 cummins last of the mechanical ones) and then i got a cousin the dabbles in diesel and theirs to much electronics for me to play with this truck...

It seems like all of the Cummins IP's are prone to failure from fuel starvation. The older ones failed shortly after the LP failed, but I'm not sure if the newer ones were the same deal or just not enough pressure. If I had to guess, I'd say it was from a complete LP failure and not just being a weak pump. Mike

Thats correct... on the early 24Vs I am certain that the lift pump was NOT a Flow-on-fail pump, thus it wrecked the IP almost instantly once the LP died. Whether they fixed that/when/how I do not know. I do know that you just need to maintain the correct pressure and volume with clean dry fuel and the pump should do fine. I think Airdog makes a HO LP and a couple other high-volume pump companies are set up for this. One huge benefit to the 24V Cummins is that they are one of the most popular engines to modify so there are TONS of aftermarket parts available.

I have a '99 24V cummins with the VP44 injection pump. I'm pretty sure they stopped using the VP44 in 2002. I have heard that they changed because of the common problem with them, and that the newer ones aren't as sensitive to low fuel pressure.

My lift pump did get weak and cause gradual destruction of the VP44 until it broke down on me one day. $2000 for a new pump and a lot of anger later I learned that you can install a low fuel pressure light to warn you if the lift pump is weak or if your filter is plugged. I HIGHLY recommend it, even if you have a post 2002 cummins. The original lift pump starts to wear out between 120k and 130k, so searstractorfan I would get a low pressure light and install it ASAP.
An aftermarket lift pump is a fine replacement, because even a performance pump will wear out and get weak eventually. Besides, pressure above stock levels aren't going to help anything unless your pump is tuned to the point of needing higher input pressure.

About $55 for the low fuel pressure light here:
http://www.bluechipdiesel.com/productpricing.html

'03 & newer have the CP3 pump.
Smarty JR is by far the best (popularity & highest HP wise) tuner out for the Cummins. The Smarty (not the JR) has TONS more adjustment. If MAJOR mods are in its future I'd go with the Smarty. If just basic mods, go the Smarty JR. Everyone rants & raves about them.
My '04.5 Cummins 2500 CC 4x4 AUTO with 33's (that I sold 3 days ago) would average mid to high 18MPG. My bro-in-laws 04.5 (had 35's, now 32's) gets almost the same mileage. Overhead makes us all warm & fuzzy as it always reads about 2 MPG higher than the actual. However, my Dmax is almost always nutz on. Go figure.

I like the idea of this light, how does it look mounted and such?? Easy to install?? I dont always believe sellers, but believe the buyers....Yes im only a few miles away from 120xxxmiles so im getting close to problems!!!Im not going for SUPEr mods on the truck, just minor ones that will make cheap HP that will make it last longer..Its already got a straight piped exhaust (stock size), looking for aftermarket intake...I sure do miss the mechanical pumps!!! My aunt 98 had mechanical pump and all my chevys have the mechanical pump..BUT the computer makes so much more power!!Ya my unce's Dmax display are spot on on theirs, but my dodge is 2 to 3 mpg off...makes ya feel GOOOD!!!

The light is extremely easy to install. The sensor replaces a plug on the top of the fuel filter and the light needs a small hole drilled anywhere to mount it. Two wires, one to sensor and other to ignition source(fuse box). I mounted the light on the A-pillar where even my wife would see it.

I'm not sure your CP3 pump had the same problems with low fuel pressure as the VP44. Might do a google search on that.