I Bought my truck in January and the only thing Ive done to it was chop out the resinator and muffler cause it rotted at the muffler and I put full 3inch straight pipe out the back cause it was free. Also I put 35s and a 3in lift on it. Now i want to start making alittle more power, I was told you can just adjust the pump and get double the power for almost no cost but I dont know what to adjust it to. I work on cranes and all of them have 5.9 12v in them so im somewhat familiar with them but i have not done to much with the engines there other then head gasket jobs or replacing turbos just simple replacment work never mods. Mine is stamped on the tag 185 HP and the trucks got 285,000 Miles on it but im 90 percent sure its not the orignal motor. My trucks also Auto and Im averaging about 15mpg. Ive heard that these trucks should get around 20mpg What can I do to get better mileage and get maybe double the power at the same time to it?

 

Mpg has alot to do with where you drive and how you drive it, the 35's arn't bad but also don't help. I am unfamiliar with the 12v motors but getting better with them. I'm not sure where the adjustment screw is but there are plenty of guy here that do. Try to post this ? in the 12v cummins section and you will get a better response. Welcome to Diesel Bombers and enjoy your stay.

 

Welcome to the bombers! The first thing you should do is gauges. Cheap insurance against melted pistons. Look into boost, pyro, and trans temp. Then a good start is to mess with your fuel plate, whether you buy one or make your own as well as modifying/adjusting the AFC. There's plenty more you can do. Look around on the forums for a while and you'll get tons of ideas.

 

first gauges.. (egt, boost, and tranny) then fuel plate to #100, star wheel full foward, afc housing full foward, straight pipe (which you did)
heres what he different fuel plates look like...
https://www.dieselbombers.com/12-val...-profiles.html
heres a cutaway of the p7100 pump
https://www.dieselbombers.com/12-val...ay-photos.html
heres a write up from DM... read it an i bet you will have no questions
https://www.dieselbombers.com/5-9l-1...2-valve-2.html
oh and you HAVE to do the KDP (killer dowel pin)
heres how
https://www.dieselbombers.com/dodge-...l-pin-fix.html
but if you do all of this your gonna get a little smoke... which isnt bad...imo... and all of these mods are free (if you grind your own plate.. its REALLY easy and execpt the kdp kit) but your gonna wann get a cold air intake or a BHAF to increase the amount of air... if you get an aftermarket intake, it will help with the mpg deal.. ...
that will keep you busy for a few weeks... but after that,
5in exhaust
bigger turbo or twins
bigger injectors
heres wut to do to get to 500 ponnies hahah
remove your fuel plate
add 181dv's
add 2095 mack rack plug
4k gov springs
64/71/14 turbo
good set of injectors like a 5x12 should be fine
head studs
17-18* of timing
and make sure your trans will hold the power
hope this helps man!!

 

Nice post

 

 

Why do you not thinks it’s the original engine? 98s came with a lot of odd ball things. However a 185 pump is not a standard pump. What color is the engine/pump? The best way to tell what pump you have is from the plate behind the throttle linkage on the drivers side of the pump. Theres a bunch of #s on it post them up and we can learn a little more about your truck.

You must also know what pump you have to set your timing.

A fuel plate, Injectors, Bumped timing to 15.5* - 16* turbo in the 62/71 area and a properly setup/tuned AFC should help with your MPG... If you can keep your foot out of it.

Good post Wisconson R

As for 500hp you should have 181s unless its not the original pump. I would also go with 5X14s if I were shooting for 500+ myself. Its also a good idea to add 60lb valve springs when adding a 4K kit.

 

Wow, I didnt think I'd get so many respones. Thanks for all the info you left its very helpful. I think ill invest in some gauges this week if I got the extra money. To answer a few of all your questions, I dotn think it was the original motor cause the whole engine and turbo are a dark grey color but the front timming cover is a beige color and some one looked at it and said it had one of them tags on it that if it over heats they fall off like most reman motors do?? but I didnt question it when they said it and darned if i can find it cause I just looked and didnt see one. But I took pics of the engine ID tag on the side of the timming cover and i never noticed all the way at the bottom or left side of it it has a build date of 11-07-98 so im thinking it might be original now so i decided to look for a build date for the truck to compare but someone before me ripped the build sticker off the drivers door, and the HP rating on the tag is 180hp not 185 i made a mistake there. IS there any other info anyone would need off this tag? The engine pump is dark grey like the rest of the motor and its a bosch p7100 Im going to have to get a mirror to see if i can read the numbers off the id tag behind the throttle linkage. Also i really dont drive the truck to hard so I dont think the mpg is related to that. Well im going to changed the fuel filter and polish it today so ill check into the pumps number and repost later tonight! thanks guys

 

What most likely happend is a KDP failer and someone replaced the case. I would still pull the cover off and make sure the KDP was tabbed. I would also still check your pump so that you know what pump you for sure have. Dark gray is the color they were when put into the dodges. Cummins cream would be the color of a reman or an Industrial engine/pump unless someone took the time to paint it. If you ever pull the timing case cover off on any cummins you will see that cream.

 

sweet let us know how it goes!!!! oh and the 60lb valve springs are a good idea.... forgot about them!!