'03 Surge, lope, pulse, buck, bounce, oscillate... uphill with load

[WesJohnston]

I have an '03 3500 5. 9L automatic that is bone stock (except BD steering stabilizer ). No chips, programmer or guages installed either. I've been on vacation for more than a week pulling a 31' 5th wheel camper all over the southwestern states. (Left Wyoming in a snow storm - thawed out in CA, AZ, NV - back up to UT getting colder :{.



When pulling hills, the truck surges like I'm tapping on the throttle about once every second. I've been stopping at campgrounds with wi-fi so I can dig through TDR posts on the subject but am not finding an exact match to my problem... . not loping while going down hill with cruise on... not loping while sitting idling. My problem happens when I'm holding a steady throttle while going uphill pulling a load. I have replaced the fuel filter and lift pump (stock mounted on rear of filter housing). Glad I brought along tools :-laf - sorry I had to use them . The computer is not showing any problem codes. Any help or direction would be appreciated. Still on the road and hoping I make it back home...

 

[steved]

Almost sounds like what a 2nd gen does when the TPS (throttle position sensor) acted up, and causes the torque converter to cyclic lock and unlock. Could you have a bad APPS (accelerator pedal position sensor)?

 

[TCDiesel]

FCA or relief Valve. . It could Be the TPS on 03. . to recalibrate. dis-connect batteries for 5 Minutes... Then re-connect turn Key to on (DO NOT START) push peddle all the way to the floor 3 times turn key off. . start and drive to see if ANY change occurred.

 

[cerberusiam]

Change the fuel filter, biggest problem with something like that can be fuel contamination. Check your fuel pressure to the CP-3 also, possible its a dying LP.

 

[WesJohnston]

Update - Okay, I recalibrated per TCDiesel,s instructions then drove as far as Salt Lake. No change in what it is doing. I still have plenty of power and it still pulls the camper fine, the surge is just enough to be annoying. TC- when I did the recalibration sequence, should I get some kind of indication from the dash that it did something? (like when I check for trouble codes it says "done")?



Something else I noticed - at lower speeds (35mph) when the engine is lugging a little bit uphill and before it downshifts, the truck "shudders" like it's on a washboard dirt road. Not sure if it's something to do with the transmission or something else. Thought this may help with diagnosis if it is related.



cerberusiam - filter was the first thing I changed. (Then I changed out the transfer pump - not a simple task at a KOA in the dark so they don't catch you mechanicing in the campground). No change but now I will be carying a spare pump .



Okay guys, I'm not very good with acronyms - I need help like steved did - thanks!

FCA?,

CP-3?,

dying LP?

I will be home in a couple of days and will have my guages and more tools. I really don't want to take it in to a dealership to put it on a computer but if that is what it takes I might have to. Thanks again!

 

[JJPage]

FCA = fuel control actuator, it is the solenoid type unit mounted on the back of your CP3, it has the wire harness connected to it.

CP3 = injection pump, front driver's side of the motor, follow the fuel lines.

LP = lift pump, you already changed that.

FCA could be causing the surge, it's not a bad idea to have a spare none the less, do not buy at Dodge, go to Cummins, part #4932457, just over $100.

There could also be two other items making it surge under load, your rail pressure relief valve could be leaking, it is a valve in the fuel rail that your injection lines connect to. If you look at the fuel rail, it has one fuel line coming off the top of it, just off center towards the front, the valve is under that fuel line, built into the rail. You can test it by removing the line at the rail, gently bend it back out of the way about an inch and place a zip lock bag around the end of the banjo fitting on the line. This is a return fuel line, so it will stop the mess... . clean out the well in the fuel rail where you removed the bolt and fuel line, the valve is down in this well, once it is dry, start your truck and bring it up to 2000rpm for a few seconds(10), maybe a couple of times. If there is fuel now present in the well, you relief valve is leaking.

It could also be your rail pressure sensor, it is the sensor on top of the fuel rail with the wire harness connected to it. NOTE: A faulty sensor will usually... set a code.

You can purchase the whole fuel rail, complete with relief valve and sensor, for less money that buying separate.

Here is a link:2003-2007 Common Rail 5. 9L

As mentioned earlier your APPS could also be getting funky, it shows it in the link I gave you, but I would not buy it from them. We have a member who makes a replacement APPS, which is cheaper and much better:Timbo APPS

Jess

 

[TCDiesel]

1st guess Pressure relief Valve, 2nd guess FCA. Running the RPMs up when checking the PRV would not be my recommend practice. just unplug the FCA and see if the trucks RPMs rise and it rattles and knocks... If does NOT rattle or Knock PRV Bad,FCA May be could, report back.

 

[sag2]

Not sure if it works on an 03, but when it starts to do it, press lightly on the brake pedal just enough to turn on the brake lights. That should unlock the torque converter. See if that makes a difference.

 

[WesJohnston]

Update - made it home to Wyoming... snowed while unloading the 5th wheel... figures!

I'll start making a run at the recommendations you guys have given me and I'll let you know what I find out. You guys rock! Thanks!!!

 

[WesJohnston]

Finally got a day without snow/rain...

I re-calibrated the TPS again per TCDiesel's instructions...

Checked for leaky PRV per JJPage (sorry TCD!) - no leak...

Unplugged the FCA per TCD and got a rise in RPM and it knocked and rattled like crazy...

Still no trouble codes showing...

Took it for a drive and I can still feel the surge (not as prominent without the camper - may have been doing it for a long time but I never noticed it 'till we took the trip).



Are there more tests or do I start replacing parts? I still don't want to take it to a dealer but we have some good guys at the Cummins shop about 100 miles south of here

 

[Wingate]

Is the tach making any movement when this happens????? MY 2nd gen Dodge gasser did this when I was having TC issues...

Also, do u have a boost guage to see if load is increasing/decreasing???,,, Could this be a wastegate issue???

 

[WesJohnston]

Tach moves just a little with the changes in RPMs when it pulses (with the camper on for a good load - didn't see it when I drove it empty) but it doesn't bounce or spaz out. No guages have been added (YET) - starting to seem like a good idea! I haven't ever heard my Dodge do a wastegate "dump" like I have on powerstrokes.

 

[WesJohnston]

Looks like a cure!!!!

Alright folks, I'm resurrecting this post from last year to update and thank y'all for the replies... Due to other things happening with the family I hadn't had a chance to really attack the above problem until recently.



Just to clarify one thing about my tach reading, I hooked onto my camper and pulled it up a grade to see just what it was doing. The pulse showed as a bounce on the tach of right at 100rpm which occurred approximately once every one to one & a half seconds. This is just for anyone reviewing posts trying to diagnose a similar problem. It didn't feel like the TC locking and unlocking (and touching the brake as suggested did nothing) but I can't positively rule that out.



Since then, after searching and reading TDR for the past year, I made the decision to make the big splurge! I ordered and installed a BD Diesel APPS noise isolator for '94-'04 Dodge Turbo Diesel trucks (Geno's part #BD-1300030) for $23. 75.



This week I hauled a 36. 5 ft Keystone Montana 5th wheel over South Pass for a friend. The camper is considerably heavier than mine. It was Beautiful... no more pulse. The '03 pulled the camper up those grades just as smooth as could be expected (considering the road surface). It could be just a coincidence but it looks like the simple and inexpensive fix worked :-laf Oo. . My biggest problem now is I ended up with a bad case of "camper envy" It was 19 years newer than mine:{.



Again, my thanks to all of you who posted to this thread and gave answers to others with similar problems. This site is outstanding and I tell anyone I run into that is running a CTD about it. Keep up the good work.



Wes

 

[sag2]

Thanks so much for reporting back your fix. That's what really makes it nice when you close the loop and confirm peoples suggestions. Glad you got it repaired.

 

[JJPage]

Yes, Thanks for sharing!

 

[WesJohnston]

Okay guys, I've got one more question about this. The reason I got it in my mind that it wasn't TC lock/unlock is because I was picturing the lock/unlock as a shift, something substantial that you would hear and feel, you know - like when the transmission shifts gears. I just got to wondering, is the TC lock/unlock more subtle, like the 100 rpm surge I was getting. If so, that's what it was.

 

[cerberusiam]

It was only partially unlocking the TC then. Under a load and any thing more than just light throttle 300-500 rpms is the normal difference between lockup and fluid coupling on a stock TC.



There are any number of causes for the symptoms you describe. The only thing that is a good bet is the original problem is not fixed, just masked by the noise filter.



Its an expensive fix but have gone as far as replacing the TC with a triple disk to cure an intermittent lockup problem like you describe. The triple does not unlock under the surge conditions because it takes longer to perform the lock\unlock.



Since it is obviously in the lockup circuit, I wonder if replacing the VB harness and\or TC would net the same results.