Engine/Transmission (1998.5 - 2002) Stinkin rough idle in park (Intermitten)

[AFaustini]

#@$%!:{#@$%!:{1998. 5, 5. 9, 24 Valve, 2500 Dodge P/U with 190,000 miles
Installed fuel pressure gauge, Air dog filter and pump, along with a new VP44 from RPM Diesel in Fort Lauderdale, FL. at about 183,000. Today it cranked up and ran fine until I got to work backed up and put in park. Thats when I noticed the rough idle. When I got off work it started and idled fine, ran with no loss of power all the way home at 12 PSI. At the first light off the interstate it idled fine but when I got home it started to idle rough, and then when I put it in park it became noticeably worse but revved in park and accelerated fine when put in drive. Tonight I changed the filter on the Air Dog and checked for any noticable leaks but found none. After, I cranked it up and cracked each injector to see which one would make it get worse or not change. Unfortunately, all of the seemed to show evidence that its not the injectors. Please Please Please help, I have come to realize that there is not one good cummins diesel mechanic down here and I don't have enough vaseline to go to a dealer. Forgot, it didn't throw any codes either.

 

[Sticks]

Any smoke at idle, or park/neutral when you rev the engine during the rough idle?

Autos do weird things to the trucks, and I have little experience with those.

 

[AFaustini]

No smoke in idle/neutral a little smoke when running down the road but not more than normal. A few friends seem to think that it's a timing issue/electrical. I plan on selling this dodge and purchasing one with a p pump etc. Thanks for the reply.

 

[rkressg]

My truck just started doing the same rough idle. I do not have any codes, no loss of power, no more smoke than normal, it just idles like it is only on 4 cylinders.

I have not changed anything recently on the truck.

 

[BIGNASTY]

Just thinking any air leaks? Just ran new filter/and lines for sons truck from tank to Cp3 and he said it got better MPG and ran smoother. All we did was to add a Baldwin 1212 in front of the AD 100 new filters on the AD and added a Cat 1R 0750 filter before the cp3 and all new half inch fuel line. He never had a fuel leak but the only thing I could think of was an air leak when running

 

[AFaustini]

Appreciate the advice but I have gone over the fuel system and found no air leaks, but I still might change out all lines just to elimiante if nothing else. What is really weird, is that it will crank up cold or warm, no smoke, no codes, when in park it will idle fine when cold, but when up to temp and in park it will idle like it has a cam. When up to temp. and in drive at a red light it will idle fine, its just when in park and at temp it idles rough. I refuse to replace pump, the stubborn side in me will find the issue and then attempt to repair without being a victim of stinkin electronics and the MAN. I have found some interesting vids on you tube of people repairing VP44 electronics. Before I forget I ahve also checked the key on the VP44 and it is fine along with timing marks on injection pump gear. Last but not least does anyone know of a cummins mechanic in south Florida worth refering. Thanks again and I will keep you all informed as the issue progresses.

 

[AFaustini]

Update

Fuel pressure good, injectors good, no codes, replaced RPM and Crankshaft sensor. Checked all electrical connectors and cleaned with dielectric grease if needed. rechecked torque on VP44 nut, good. Rechecked harmonic balancer, good. Any advice at what else to check or it could be? Thanks for any advice suggested.

 

[BrooksElder]

I am fighting the same issue rough idle usually when engine is warm. I've added AD 165, new vp, cam sensor, adjusted valves, which all helped a little but not fixing. Had injectors test done by shutting each one off put haven't pulled to test yet. I'll let u know it i find anything that fixs my problem.

 

[AFaustini]

Refusing to give up!

Thanks for the input, I find it interisting that you replaced the VP and still have the rough idle when warm? The only time it rough idles is when it is up to temp. and in park. If at a light in drive but not moving warm or cold it will not miss idle. It's just when up to temp and in park. Some have suggested the APS but I disagree as there are no codes after several checks. But when in drive or reverse, accelrating it runs like a champ, no smoke, and no loss of power.

 

[Sticks]

Someone in another thread with some of the same issues found out his harmonic dampener went Tango Uniform. Might check that for cracks.

 

[AFaustini]

Thanks for the advice I take it off and check it.

 

[rkressg]

My Damper split in half at the hub where it bolts to the truck.

 

[AFaustini]

But do you think it would cause such a problem as I am experiencing?