Engine/Transmission (1998.5 - 2002) stumble revisited

[Agades]

condition:

rythmic stumble from 50 to 60 mph, 6-20 psi boost

(just like the low rpm lope we all have)

and doesnt seam to stumble with cruise on

definitely an electrically induced fueling spike



setting codes 0500 (no vehicle speed sensor signal)

0253 (fuel pump fuel valve open signal)



codes only show when below 0 degrees and clear themselves after driving but stumble persists



problems all showed up at same time when i had the dealer install a con ofe clutch and do an unneccesary reflash to enable high idle

Looking back , this is also about the time it started to get really cold here in Minnesota. so problems may or may not be related to clutch or reflash.



after problems showed:



- checked voltage on IAT

- replaced fuel filter

- checked fuel pressure (have fuel press guage but senders dont last more than a week so dont trust)

- checked voltage on map

- checked connection on speed sensor

- dealer replaced PCM

- sent ufm to dd came back ok

(doubt it was comparable temperature to minnesota)

- drove stock for about three weeks

( only 0500 code set , stumble still there but not as noticeable, also not as cold out either)

(should probably try again but dont like stock)



- dealer told me 0253 code is normal in cold conditions

(i dont believe that)

- voltage on APPS is somewhat erratic so I am replacing when it shows but this probably wont fix codes



My theories:

- reflash caused a problem in ecm and only shows in cold

- reflash caused a problem in ufm and only shows in cold

- bad connection on a connector that contains pump controls and speed sensor input

- tech wrecked speed sensor when installed clutch (dont know if this is possible or not)

- circuit in pump bad (but why would the check engine light shut off again)

- ufm harness bad connection

- cracked circuit board in pump from bc pump cover

- cracked circuit board in ufm just enough to act up in cold

CAN i RULE ANY OF THESE OUT??



these problems all seem to be relative to temperature



the tech at my dealer is very incompetent but he ist jerking my warranty

and I can get him to go for a ride with a scan tool if this would help anyone properly diagnose this problem



help!help!help!

 

[EShaw]

- bad connection on a connector that contains pump controls and speed sensor input





Replace your brake switch... ... ...

Drive it and tap the brake without letting off of the go pedal... ... same thing. Hope this helps.



Eric

 

[Agades]

my brother was driving it and held the brakes a bit while holding speed (to add load)

stumbled in the same spot but stopped stumbling as soon as he gave more pedal (over 20psi boost)



I dont know if this is what u are referring to or not

 

[Agades]

took off the ufm and harness



codes did not appear yesterday at 1 degree obove



codes both appeared today at -12 degrees after driving for an hour



stumbling barely noticeable but is there



still have pump cover on



HAS ANYONE EVER CRACKED A CIRCUIT BOARD FROM THE BC PUMP COVER???????



WHAT ARE THE SYMPTOMS????????

 

[Agades]

star center shut down the dealer on the APPS

they will not OK



star center also wont ok a new ecm after the bum reflash



star center also told the dealer that 0253 is normal in cold weather



dealer cant find any problems relating to codes



Me Think Star Center Dumb



so I airmailed ecm to cummins today for a re calibration



we shall see what happen next

 

[CstlEng]

best guess at this point is your vehicle speed sensor was not 100%. $39 part and easy to do on my 99 4x4 (one bolt and plug on top of rear diff), I am not sure about your truck. Cleared my VSS code though. For you it would be a low $$ thing to eliminate, and might even get rid of the one code. My stealer is by no means a good one, and I was shocked when they had the part on hand: they said it was fairly common to replace.

Its location makes it fairly difficult but possible to be hit by debris, but I have noticed lots of ice buildup on it, and it can be splashed easily. Mine was cracked and filled with water and worked worse (eventually) when colder (frozen). It first showed as speedo reading normal over about 5 mph, but 0 below 5 mph. I never really noticed it. It stayed like that for about a year, then after the first freeze it jumped to 20 mph and got worse.



Another post similar to yours found their solution in the replacing of a faulty APPS (accelerator pedal position sensor). either they or my haynes book explained an in depth way to test this more expensive part (I think $400 or so from the stealer).

 

[Agades]

Originally posted by CstlEng

best guess at this point is your vehicle speed sensor was not 100%. $39 part and easy to do on my 99 4x4 (one bolt and plug on top of rear diff), I am not sure about your truck. Cleared my VSS code though. For you it would be a low $$ thing to eliminate, and might even get rid of the one code. My stealer is by no means a good one, and I was shocked when they had the part on hand: they said it was fairly common to replace.

Its location makes it fairly difficult but possible to be hit by debris, but I have noticed lots of ice buildup on it, and it can be splashed easily. Mine was cracked and filled with water and worked worse (eventually) when colder (frozen). It first showed as speedo reading normal over about 5 mph, but 0 below 5 mph. I never really noticed it. It stayed like that for about a year, then after the first freeze it jumped to 20 mph and got worse.



Another post similar to yours found their solution in the replacing of a faulty APPS (accelerator pedal position sensor). either they or my haynes book explained an in depth way to test this more expensive part (I think $400 or so from the stealer).

thank u

very good info

I will try this after my ecm returns from its trip (if code returns)

the tech at my dealer told me the only way star center will warantee my APPS is if I rob one off a new truck and try it and it cures the problem :-{}

did you get 0500 code or 0501????

 

[CstlEng]

APPS is easy to swap, as long as you have one.



I looked in my log and I didn't write down the code number. I usually write down everything. Sorry I can't remember... it was 500 or 501 though... and 500 seems to stick in my head.

 

[Agades]

problem fixed!!!!!!!!



cummins (not dodge) reflashed ecm

-no codes

-no stumble

-make me very happy



hooked up new edge comp and works great, smooooooth

(DD neglected to tell me that I had an outdated ufm when I sent it in 2 months ago and that I should replace it)



I replaced the pump cover for a pm grabber (very nice tool)



I KNOW THE PROBLEMS CAME FROM THE DODGE REFLASH AND I THINK ITS BECAUSE I HAD THE UFM HOOKED UP WHEN THEY DID THE REFLASH



BIG OOOPS





A VERY BIG THANK U TO:

ROD @WILDCAT

AARON @EDGE

MIKE AND RUSS @ ROCKY MTN CUMMINS



THESE PEOPLE SHOWED VERY EXCELLENT CUSTOMER SERVICE WHEN OTHERS GAVE THE RUN AROUND



THANK U THANK U THANK U