new FCA still rough idle

[KWG]

i installed a new fuel control actuator from cummins, that didnt do the trick so i installed a new fleetguard fuel filter and like the FCA still running rough. i have noticed a little white smoke when i start it cold. the motor sputters a little when i accelerate when cold. i took it to all-star dodge here in amarillo, they told me there is nothing wrong with the fuel or the motor, but the stock clutch is bad, huh thats funny because i installed a new valair clutch at

45000. i still dont understand how my clutch would effect the the way the motor runs. i took the truck back from all-star and going to take it to a different dodge dealer this week unless anybody has any ideas. current miles on truck is 66000.

 

[HBarlow]

I would take the truck to a competent Dodge dealer service department and ask them to run a "cylinder performance test" at your expense. It will cost you an hour or hour and a half of labor (approximately $150). If they don't know what it is or see the merit of running the test run immediately from that service department. If they find a marginal injector or, worse, a failing injector, it should be covered under warranty. If everything tests out good you'll be out $150 or so but know that nothing is wrong. An injector that sticks open will melt a piston and destroy an engine.

The problem we often run into at a Dodge dealer is few techs own and drive a Cummins powered Ram so they are not as familiar as most TDR members are with the trucks. They know how to diagnose and repair them but are not as likely to notice minor little performance issues as the owner is.

Also, if the truck is in warranty and you are expecting diagnosis and repair at no charge they have to consider how they're going to be paid for their time. If they don't recognize a problem and you have no evidence they are often forced to conclude no problem exists. It may sound unfair but it is a simple reality. The service department has to earn money to stay in business. A mechanic has to earn money for his time to stay there also.

Try PMing Mike Mullenax here on TDR and ask him what he recommends. He is the lead diesel tech at Elder Chrysler/Dodge/Jeep in Athens, TX, a friendly small town dealership in East Texas. I visited Mike at his store last week to have him do a reflash on my ECM. Mike is a good guy and is as knowledgeable and helpful as any dealership tech you'll ever meet.

Having said all the above, some white smoke at startup may be normal and occasional rougher than normal idle seems to occur at random. My '06 did it sometimes. I don't know why. I wouldn't jump up and spend a lot of money just based on an occasional perceived rough idle or light white smoke on startup. As a matter of fact, I wouldn't do anything more than run a bottle of Fleetguard injector cleaner and have a cylinder performance test done until a real problem is identified.

How many miles are on your truck and how is it used? If you don't tow regularly or run it hard on the interstate occasionally you could just have some carbon build-up on injector tips. Cummins sells and recommends an approved Fleetguard brand injector cleaner you might want to try. You can buy it from the Cummins store in Amarillo.

Come back and post again if you solve your problem, or, if you don't. Maybe someone with real mechanic knowledge and skill can help. I can only share my limited experiences.

 

[JJPage]

Sounds more like an injector. Might just be debris/carbon, you could try and run some Valvoline injector cleaner or Seafoam through the system and see if that will clear it up.

 

[HBarlow]

Oops, I just noticed you have a magic black box in your signature. That changes my recommendations. I simply have no idea what may be wrong with an engine that has run a magic box. I don't use them and have zero experience with them. Use of the Smarty box may have caused damage to one or more injectors or other components.

Several TDR members become angry everytime I express my opinion about magic black boxes but here it is anyway: Adding a box to enhance performance alters injector timing and rail pressure. Either one of those alterations creates an operating environment beyond that the engine was designed, built, and tested for. It is, in my opinion, a risky thing to do.

I believe the injectors in our engines were designed and manufactured to perform reliably for several hundred thousand miles under factory stock conditions. When you alter injector timing you alter compression pressures, sometimes significantly. IMO opinion, the factory injectors are fragile if subjected to magic black boxes.

As far as I can learn from TDR member comments, all magic boxes increase rail pressure. The factory injectors will not withstand higher rail pressures with the same reliability and durability as they will factory design pressures. In plain language, magic black boxes cause injector failure. Higher rail pressures cause the tips to crack, split, or break.

You have a problem with taking your truck to some dealers because of the black box. If they suspect the truck has been modified or "hotrodded" and you're in complaining of an engine issue under warranty they will be less cooperative about any and all warranty diagnosis requests or repairs. If they run any diagnostic tests on the engine they can detect presence of a magic black box, even one that has been removed. A sharp dealer tech knows how to find the trace evidence. Your warranty is void now anyway.

So, you have a problem! The way to solve your problem is to repeat after me, "I modified my truck, I am my own warranty company. " Once you accept that fact, your problem is reduced and the solution becomes clear.

Take your truck to a good, honest dealer service department with at least one Level IV trained and certified Cummins tech and acknowledge the former use of a black box and ask him to run the cylinder performance test at your expense. The test will measure and compare the power output of each cylinder. A weak injector or other component will show up under this test. If he finds a problem, get out your credit card or check book. If he finds nothing, maybe you are lucky.

I'd still PM Mike Mullenax and tell him the truth and ask for his advice.

 

[KWG]

The pickup is a daily driver and i only tow my rv accouple times a year for work. the trip over to amarillo was the longest haul i have done and the most work out for the cummins. I never hotrodded it, always knowing this pickup makes me money,so it has been babied. i ran my smarty at a low level and took it easy following a half ton pulling an rv. At this point I am prepared to pay for repares knowing i voided my warrenty but with a little hope. Its at the shop now and tomorrow morning i will call them and have them run a cylinder injector test on me. we will see tomorrow. yah know the strange part is once it warms up it runs smoother than the day i bought the truck.

 

[Alaskaskiff]

Regretably injectors go bad even with 2 micron fuel filters and no performance mods.

 

[HBarlow]

... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... . yah know the strange part is once it warms up it runs smoother than the day i bought the truck.

You may be needlessly worrying about nothing if it smoothes out after it's warmed up. Hopefully you'll get a good report from the cylinder performance test and can be confident you have no problem.

Let us know what you find out.

 

[KWG]

Turns out i found a diesel tech at texas dodge who knew what to look for. a cylinder performance test was completed and they identified injector 5 wasnt running properly. the labor and parts are still under warranty, and ill get the pickup back tomorrow.

 

[Regcabguy]

Neighborhood Cummins guy.

Turns out i found a diesel tech at texas dodge who knew what to look for. a cylinder performance test was completed and they identified injector 5 wasnt running properly. the labor and parts are still under warranty, and ill get the pickup back tomorrow.

Congratulations! For future reference,you've got a first class Cummins diesel guy in your neighborhood. His name is Fred Swanson. He owns Desert Diesel Parts in Waddell. # 623-910-9575.

 

[sag2]

You have to be careful using the cylinder performance test. It is not reliable for diagnosing a bad injector, and Dodge warns not to use it. It really is not as good as capping off an injector one at a time.

 

[HBarlow]

You have to be careful using the cylinder performance test. It is not reliable for diagnosing a bad injector, and Dodge warns not to use it. It really is not as good as capping off an injector one at a time.

I guess I'll have to add that caveat if I give similar advice in the future. I didn't know Dodge didn't consider the test a reliable tool for diagnosing bad injectors.

How do you cap off an injector? Does that mean simply disconnecting the wire that triggers it or ... ... ?

 

[HBarlow]

Turns out i found a diesel tech at texas dodge who knew what to look for. a cylinder performance test was completed and they identified injector 5 wasnt running properly. the labor and parts are still under warranty, and ill get the pickup back tomorrow.

Good news. I guess you were lucky.

 

[KWG]

thanks for everybodies help. everything worked out

 

[Alaskaskiff]

Capping an injector is not on the electrical side, but rather done by disconnecting the line and capping the rail where that injector is supplied. You then run the engine and measure flow return over a specified time. The hard parts are getting enough stuff out of the way on top of the engine to do this and also to ensure that you isolate on the common injector return, as the high pressure pump and the rail both have returns that skew results. Takes about 1-2 hours depending on skill and requires a couple special tools (cap) and banjo bolt to barb fitting for a separate return hose. The process is described well in the Cummins Service Manual for our engines, which is available online through Cummins Quickserve (account required) or at a Cummins dealership.

 

[AH64ID]

As far as I can learn from TDR member comments, all magic boxes increase rail pressure.

Not true. The Smarty Jr doesn't add pressure, The Sr only does when options are adjusted, the Edge Juice doesn't, and I am sure there are others that don't as well...

 

[HBarlow]

Not true. The Smarty Jr doesn't add pressure, The Sr only does when options are adjusted, the Edge Juice doesn't, and I am sure there are others that don't as well...

How can they increase power without increasing fueling?

 

[AH64ID]

How can they increase power without increasing fueling?

There is a difference between pressure and duration. They achieve power thru duration and timing. Like SW1 on both the Jr and Sr smarties is timing only, no additional fueling. They make up to 55hp/100ftlbs more at 2K rpms without any extra fuel. . timing is where the mpg gain comes from. Duration is holding the injector open longer, so more fuel gets thru. Pressure is increasing the pressure so there is more flow when the injector opens.

 

[HBarlow]

Okay, thanks for the explanation. I know nothing about the black boxes but have read on more than one occasion about fuel pressure increase resulting from some of the boxes.

 

[AH64ID]

Okay, thanks for the explanation. I know nothing about the black boxes but have read on more than one occasion about fuel pressure increase resulting from some of the boxes.

Yes some do, in fact its all some do(MP-8, Edge EZ). . I personally don't want to mess with pressure.