03 H.O. running rough.

[blacksheep4x4]

Well we just got back from a 1600 mile trip with my 03, and when I stopped the truck in front of the house The truck coughed. It started running rough like it has a miss. Finally got it to run smooth again and then I started to hear a rattle coming from engine compartment. It would only rattle after running the RPMs up and letting of the throttle. It is a light rattle (not a rod or anything). I am thinking maybe an injector?? Is what has been happening the sign of a bad injector, or a bad fuel pump? I know it's not a plugged fuel filter. I changed that out thinking that was what it was to begin with.

Thanks in advance.

 

[Pawpaw]

Well we just got back from a 1600 mile trip with my 03, and when I stopped the truck in front of the house The truck coughed. It started running rough like it has a miss. Finally got it to run smooth again and then I started to hear a rattle coming from engine compartment. It would only rattle after running the RPMs up and letting of the throttle. It is a light rattle (not a rod or anything). I am thinking maybe an injector?? Is what has been happening the sign of a bad injector, or a bad fuel pump? I know it's not a plugged fuel filter. I changed that out thinking that was what it was to begin with.

Mine did the same thing 2 weeks ago. I was running on the highway and noticed it when I pulled into a truck stop to change fluids (mine, not the truck's :-laf ).



While I was inside, I bought a quart bottle of Power Service Diesel Kleen and got back on the road. About 100 miles later, when I pulled in to fill up, I dumped the entire quart in and filled the tank.



The next time I stopped, the Cummins purred like a kitten.



I've been using Howe's Meaner Power Cleaner in every tank. As soon as I finish up the two bottles I've got now, I'm going to change over to PS/DK. Might even add a little MMO to see how that works.



Bob

 

[blacksheep4x4]

I hope that is all that is wrong, but I doubt it. The truck gets injector cleaner added to its fuel regularly. I am also wondering if it may be the MAP sensor. The truck has 198,000 miles on it now.

 

[MRosinski]

When was the last time the valves were adjusted?

 

[blacksheep4x4]

It has been quite some time since they were adjusted. I'll check that tonight.

 

[MMeier]

Hmmmm... . mine has a similar condition upon hot start up. IF my boys at the trans shop in Utah ever get done, I'll swing around the corner to II and let them have a look see and see what they think. I know my relief valve dribbles some when I take out the banjo bolt, kinda hoping it is losing pressure through there and not an injector.

 

[CBradford]

I have a 03 HO with 75k..... my truck has had a fluxuating idle for about the last 15k miles..... i've been ignoring it up till recently..... it only happens when the truck is warm and it's hot outside..... finally it cut off one time in heavy traffic..... so i started looking for a fix... . i replaced the relief valve and checked injectors and valve lash... ... injectors had buildup but didn't seem damaged..... relief valve did not net a change in performance..... so i broke down and took the truck to the dealer..... they say fuel control actuator..... they have one on order so we'll see what that does... ... they say it's covered under 100k engine warranty too..... i'll report back once it's on... .

Corey

 

[MMeier]

. . so i broke down and took the truck to the dealer..... they say fuel control actuator..... i'll report back once it's on... .

Corey

Please do ! If you let it idle on its own, will the idle jump up a couple hundred, say to 12-1300 , then back down, as if it's trying to compensate for something?

 

[CBradford]

EXACTLY..... hope to have the truck back sometime this week... ... i know there's a lot of trucks out there with these same symptoms.....

Please do ! If you let it idle on its own, will the idle jump up a couple hundred, say to 12-1300 , then back down, as if it's trying to compensate for something?

 

[MMeier]

Is that FCA thingie a dealer item only, or can you get one at Cummins?

 

[CBradford]

FCA is @$200 from the dealer... ... i'm sure it's available from cummins too but i haven't tried.....

 

[blacksheep4x4]

Do you know if it is easy to change?

 

[CBradford]

not real sure... ... you can see it plain as day on the back of the pump... ... i don't think you have to remove the pump..... i'll have to look in the service manual... ... but i'm lettin the dealership do this one since they said they would under warranty.....

 

[blacksheep4x4]

I don't know what is going on with this truck, but now it is running just fine. I am still going to take it in and have it checked out though.

 

[jjdiesel]

What about the Banks six-gun stuff... could it be getting tempermental for some reason? Try un-plugging it?

 

[BradyWilliams]

Sorry I am posting late here but you are dealing with a classic stuck nozzle or a bad control B&P. The filteration MUST be increased to 2 micron with water stop paper. If you have a DRB3 you could isolate which injector you have bad. But don't be suprised if there are more than one. We have seen low mileage injector failures (less than 10,000 miles) due to poor filteration. As I have posted in the past you will need better filteration or you will see failures. Let us know if we can help. Thanks, Brady

 

[MMeier]

I don't know what is going on with this truck, but now it is running just fine. I am still going to take it in and have it checked out though.

was the weather cooler today? Upon my visit to II this morning when I picked up my truck, with the DRB tool hooked up, we saw that the inlet air temp was higher then they felt it should be. Noticed trhat the fan is blowing nice hot air right onto my torque tube and right onto the IAT sensor. Going to try to wrap some insulation around it and see if it acts differently.

 

[MMeier]

Sorry I am posting late here but you are dealing with a classic stuck nozzle or a bad control B&P.

Control B&P ?

 

[CBradford]

well..... picked the truck up from the dealer today..... the FCA definately seemed to fix the problem... ... drove around for a while..... got the truck up to temperature with the A/C on and never once did it try to stumble stutter or choke out..... it was 93* here too today..... it definately would have ran rough before under these conditions..... plan to tow a trailer for a while on saturday..... that should be the real test..... but all seems well for now

 

[MMeier]

Let us know !!!