Hey all! I just picked up a 1990 cummins for cheap. Its an ex logging/work truck but now its all mine! I was thinking about doing a few mods for some more power, i will mostly use this truck to pull a 20 ft flatbed loaded with hay or firewood, and also will be pulling our horse trailers, max no of horses is 5. Anyways i was thinking of like 75 hp injectors? Brand? Fuel pin? Brand? Cold air intake? How does cold air intake work anyways? isnt it cold now? coming in from under the turnsignal? What else can i do for reasonable cost? 200 or so dollars per mod... Also what does W250/D250 mean? what is the difference? Sorry bout all the dumb questions, but only one way to learn... gutted all the carpet out of the ol girl and rhino lined it, planning on putting in 2nd gen seats. I also put in a new stereo and painted dash, put in grile and light panels. ill put pics up someday so you can see the damage. Thanks for all the input!

O, its got an exhaust break on it too, its a pacbreak, thinking it probably came with this year, however, the solenoid was taken out and its missing the return air line, but it does work! manually... I would like to get it working, does anybody know where i could get the line? I have the old solenoid, and was going to wire in a switch to replace the old rusted out push petal floor switch....Thanks again!
Henry.

 

The exhaust brake is proably aftermarket, they did not come with them from OEM. Cold air intake is when you take out side air and push it thru a intercooler or air ram, some of the ealy 1st gens do not have a intercooled engine and you can tell by if the intake goes to the radiator thru an intercooler, and then back thru to the intake horn. 75 horse injectors are good there are couple of different brands out there but their is proably no one better than another. Id make sure you have a nice and tight front end, before you make any mods. But I dont know the differrnce between a W250 and a D250 maybe diesel and gas engines.. You can proably call pac brake for the parts or find a auto shop that can make the line. You can wire in a switch in and that will work to the guy before proably thought the foot switch was a good place for him.

 

D250 stands for 2 wheel drive. W250 stands for 4 wheel drive. First things to do is go on YouTube and look up how to turn up the fuel on it and turn the pin to its steepest angle. Then you have several options for aftermarket fuel pins. Denny t and m&h inc have the most variety of different grinds. As for injectors look for 5x.011's or 5x.012's (don't buy cheap ones they have characteristics that get old). Also getting a 60mm turbo upgrade wheel from high tech turbo or gds is a very good budget upgrade that'll provide more power. The other thing is to get rid of the crossover pipe that comes on the non intercooled trucks in favour of a 2.5" piece of pipe. The thing about non intercooled trucks is they came from factory with 9mm injector bodies which are bigger than the 7mm injectors that are stock on the intercooled trucks and all aftermarket injectors so you'll need adapters to fit aftermarket injectors

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The thing to do for your intake is drill a bunch of 2 inch holes in the stock air box. That'll be all you'll need for intake

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And the exhaust brake is aftermarket. No light diesel truck came with an exhaust brake until the 6.7l cummins equipped dodges that came out in 2007.5 and that is really only a variable geometry turbine that closes the veins down to provide engine retarding power. Since then Chevy and ford have adopted this technology.

 

First Upgrade you need to do before doing any fuel upgrades is GAUGES if you don't already have them. Really wish people would let Newbies know this before telling them bigger injectors and turning the fuel up. Good way to melt a piston.

Welcome to DB

 

Yeah gauges are a must, then learning what they are supposed to be at normaly vs hot ect is a whole other ball game. I was actually looking at gauges last night! haha Thanks for the help guys, still some questions unanswered if someone else wants to chime in. My cummins is non-inter cooled, i see that many folks have pulled an inter-cooler from later year trucks and moded them in to their first gen. doesn't look like it maters if it came from a ford or a dodge, besides running cooler, what other benefits do you gain from doing this? and is it a tough process? Thanks again fellas! looking forward to hearing back from ya!
H

 

Normal highway egts is somewhere in the 700 degree area but that's with intercooler (not positive what non I/c run). Intercoolers provide cooler denser air charge allowing the engine to take advantage of more boost.

 

Do water inj. its better than a intercooler!!!!

 

A water to air intercooler run over the valve covers would be a great way to intercool the truck. Water to air I/c's have a lower pressure drop from end to end, better cooling power and less fab work to install them. You do need to run water lines to it but other than that they're much better than air/air or water meth