Engine/Transmission (1998.5 - 2002) On Vacation; 24v surge and mild stumble while pulling 10k 5'r

[npieske]

I have had this issue with my truck "bucking" fore and aft during mild acceleration, especially with o/d engaged. The problem is non-existent during heavy throttle application or WOT, regardless of load.



The immediate problem is now I am on a trip with my wife, daughter, and dogs, pulling my 10k fifth wheel trailer, 4-5 hours from home. The truck is doing the surge/bucking thing with o/d locked out now. Tach jumps approximately 25-50 rpm during stumbling episodes. I am not driving it like I stole it and not 'pouring the coals to it' on steep grades. EGT's have not been more than 1150-1200 degrees. Transmission is no more than 150 degrees. I have been blowing off my coller lines if I am too aggressive on throttle, so trying to be gentle.



Truck has superchips tuner, AFE Magnum force, 300hp bosch injectors, recent injection pump from Midwest Fuel Injection, built automatic transmission, and a new FASS complete pump replacement system. Driveline has been balanced recently also.



I am wondering if anyone has any ideas. Should I take immediate action, or wait until I get home? I don't want to be dead in the water with my family on vacation...

 

[bromano676]

Accelerator Pedal Position Sensor I had the same thing happen to me over july 4 vacation

 

[bromano676]

mine was replaced about a year ago, I used a Dodge part, it lasted less then a year. $525 from the dealer. Timbo a member on this site sells a better replacement for about $160. try reading this thread, it explains why the Apps fails, and why Timbo's is better.



https://www.turbodieselregister.com...n-1998-5-2002/198522-anatomy-apps-sequel.html

 

[BDaugherty]

Do you have a fuel pressure gauge? Low fuel psi can cause your symptoms. Aslo, what happens when you program back to stock?

 

[SKuyper]

What year is your truck? I used to have these same issues under light throttle with or without OD enabled. With OD locked out the Torque Converter still locks up in 3rd gear at about 38 mph give or take a few. The problem with mine was bad grounds between the APPS and TCM... there is a simple fix. Clean all ground cables and wires between battery/body, transmission control module and body and Engine to Frame/Body grounds. The TCM controls the ground circuit that activates the TC Lockup . . electrical noise from the alternator in conjuntion with corroded or weak grounds will cause the TC to jump in and out of lockup causing the jump and buck you are experiencing. Suncoast Converters has another fix that has you cut and splice into the APPS ground wire and run it to the dash ground wire. Here is the link to the page and the link to the .pdf instructions.

I hope this helps... I've been there... it sucks and its hard on transmissions...

Sun Coast Converters Diesel Transmissions, Fort Walton Beach FL



http://www.suncoastconverters.com/images/APPS ground rewire.pdf

 

[hcole]

My truck has been surging for about 3 weeks. No codes were set, and I researched TDR about the problem. I concluded it had to be the APPS because it ran fine on cruise and it seemed OK as long as it was running in open loop, in other words not warmed up. I researched Timbo's product and then ordered one. I put it in yesterday and have put app. 300 miles on it and works like a charm now. Thanks to all you members that did the legwork tearing the APPS apart, figuring out how it worked any then scouring the various manufacturers for a replacement. The product you found works PERFECTLY and it was easily installed. Thank you, Timbo and all others.