Hello, i am a newbie to both my cummins and to the site. I got a lot of questions about everything. But my main concern is around 1700 rps the truck kinda coughs, and shudders. Also happens if i am really stepping on it at 2300 to 2500 rpm. I have the smarty at catcher #5, 60%. the smarty isn't reading any codes. I have just replaced the fuel filter a couple hundred miles ago. I just bought the truck and am worried i may have a serious problem even though it dosn't do it all the time. Any help would be greatly appriciated.thanks

 

How many miles on it? Unplug your FCA it's on the back of the CP3 it should ratlle real bad. Plug it back in and it should recover in about 30 seconds.

 

What's the CP3 fuel inlet pressure under load?

 

hey, thanks for the replies, the truck has 116,000 miles. I don't have a fuel pressure gauge. If its a pressure problem would the check engine light come on?

 

Yes It would. Did you do what I asked yet?

 

no lights come on, it stumples a couple times and then works fine. its happens pretty quik and then its over. I just filled it up and dumped 16OZ of diesel kleen in it thought maybe it would help. didn't seem to do much.

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dangerous1965, havn't messed with it.
got home late from work (was dark) and its like 20 degrees in here north central pa. And my truck won't fit in my garage. Probally have to wait untill the weekend. thanks for the advice. I will post the resaults as soon as i can. I posted this same question on another form 2 weeks ago and got no help, so again thanks

 

Only takes a second to unplug it! Hot under the hood! it's the only wire on the back of the CP3! Let me know!

 

okay, i do it when i get home, i need to do this with the truck running,correct?

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ok, so i unplugged the plug in the back of the cp3. it ran rough,then recovered. i then drove it,still coughed and sputtered. it seems i really notice it in 5th and 6th gear. No lights came on, i was at 13 lbs of boost, egt was around 600. it got worse over 2000 rpm,then stopped. no weird noises or white smoke.

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i did notice that this happens when the engine temp is down below 190. I don't drive it every day, [as i work about 5 minuets away from home]. So when i do drive it i let it warm up for a while, then go. Sometimes it misses but i havn't seen it when its hot. Today i did some runnin around it acted up a couple times, then it stopped. worked great through the entire rpm range up to 2,600 i had to lay off of it wet roads+smarty= stained seat cover

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i did notice that this happens when the engine temp is down below 190. I don't drive it every day, [as i work about 5 minuets away from home]. So when i do drive it i let it warm up for a while, then go. Sometimes it misses but i havn't seen it when its hot. Today i did some runnin around it acted up a couple times, then it stopped. worked great through the entire rpm range up to 2,600 i had to lay off of it wet roads+smarty= stained seat cover

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oops, i know less about computers than i do diesels

 

LOL I know the feeling! Not getting it up to operating temp is not good for it! Hook up a 10k trailer and find a big hill! Clean your grounds and MAP sensor.

 

how long should i let it warm up before i drive it, i don't beat it much. I have operated deisels before ( v -12 frac pumps, cdl class a) but i wasn't paying for them .So like i said i got lots of questions. Were's the map sensor ? I hope it's nothing serious.All i seemed to hear about is bad injectors, melted pistons and other problems i can't afford. Thanks for your help