Swapped out the FCA to fix a hesitation and light throttle surging issue over the weekend. Truck is running like her old self and idles smoother, and also noticed a 50 degree drop in EGTs at idle.

Also changed out the OEM APPS with a Timbo unit. All I can say is Wow! Much smoother going into the throttle and rowing through the gears. No more jerking. Should have done this a long time ago.

Anyone still running the OEM engine mounted APPS I highly recommend replacing it with the Timbo version. He uses a high quality Williams Controls unit. http://www.dodgecumminsapps.com/index.html

MikeyB

 

Did you follow the Timbos APPS calibration instructions or did you just bolt it on and go? I've noticed on my 6sp (more so since my SouthBend clutch install) that on/off throttle has a BAD jerk....almost like gear backlash. Is that what you were experiencing? Did the new APPS completely solve that?

 

I followed the instructions for calibration. Turn the screw until the voltage starts to rise and then back off 1/2 turn.

I was experiencing the same jerk during off/on throttle application. Made a noticeable improvement in smoothness. Can't say it will have the same effect for every truck but it's a good 90% improvement for me.

MikeyB

 

That's what I hoping to hear. That jerk with the on/off throttle really feels as though it could tear something up.....it's very harsh. May have to give the Timbo unit a try and see what happens. Thanks for posting this info as I'm sure there are many more of us who are experiencing this same problem!!