hey guys-just bought a 03 cummins quad cab longbed 5 speed. Im coming from a 12 valve and don't know anything about these trucks.

My first question: Why does it high idle? When its warm it idles at about 1200 after I rev it or touch the gas. Just wondering if this is what its supposed to do? Im at 300' above sea level and its been about 85degrees.

My other question is how to get any hp out of these trucks? If some guys with modded trucks could tell me a good set up that would be sweet. Nothing huge...4-500hp??

Thanks in advance!!

 

How long does the idle stay at 1200? Mine use to do that. Hang at 1200 for a second or two when warm. The harder I worked it, the longer it would hang there, up to 5 or 6 seconds. Not to be the bearer of bad news but it turned out to be at least one injector on it's way out and CR sticks are NOT CHEAP. BTW, normal idle is 750 rpm's.

As far as power goes, a good programmer (Smarty) or module (Edge), the cold air intake or your choice and a 4-5" exhaust will make 400 hp at the wheels pretty easy. Much more than that and you'll have to upgrade your clutch as it will likely slip.

 

it stays there once it starts idling high unless i shut it off or drive it and stop again. You seem to be on to something with the injectors cuz i noticed when its idling there the "injector knock" seems to be out of chime if you know what i mean?? Truck also needs to be serviced (oil, fuel filters etc)

 

A good lift pump (FASS or AIRDOG), gauges, smarty or EDGE as stated will get you to your goal. Also as stated, its a good idea to upgrade your clutch. I all but blew up my dual mass flywheel when I had an Edge J W/ A on HOT. Not sure if the 03's had the DMF or not maybe dieseldude03 can shed some light. Good luck

 

Nope. The 03's had a standard flywheel. I'm still on my stocker.

 

thanks a lot guys. Ive been doing some research and a chip seems to get them moving for the money. Any ideas on a clutch? I put a sbc dd3600 in my 12v and loved it. Just didn't like the price and I got it cheap. This truck is a nv4500 similiar to my 12v right? Its the heavy duty with the 5 speed.

The idling is really bothering me. It runs exc and all. Its almost like tps or something?? Its weird because it just likes to idle anywhere between 750 and 1200.

If a guy with a standard happens to read this could you please answer this: When im driving and I hit the clutch and let off the gas to shift it stays at the rpm i was at for a good second after I let off. I understand that this thing is a lot more elctronic than my old classy 12v was. Its it just me or is this not how its supposed to be?

Thanks!!

 

Yeah. A common rail won't drop rpm's instantly when you lift your foot like a 12-valve will but it shouldn't hang at a certain rpm for any length of time either.

The TPS may very well be the problem. There's also a pressure relief valve on the rail that can cause idle problems. Does it show any codes? With the engine off, turn the key from "off" to "run" 3 times without starting the engine, stopping at "run" the 3rd time. Any trouble codes will be displayed in the odometer. Write 'em down and post 'em here or you can Google 'em and find out what they are.

 

P0480 and P0483

Which has to do with the fan (as im sure you know). Will check tonight and see if its a fuse like I noticed in some posts i found with google. The engine light isn't on either.

Took it for a ride and think I was exaggerating a bit with the throttle hang. I just need to get used to it

 

You will probably have better luck with a PPE programmer on 03-04 truck.

 

Smarty POD

Luke