Apps Only reads to 64% Throttle

[mz832002]

I am have a problem where my APPS never reads 100% throttle.  I am going to try and keep this short.  The truck is basically stock except for a Quadzilla Adrenaline.  The stock APPS sensor started acting up in Jan.  It was causing the truck to die will driving and lurk forward while stopped. I replaced it.  I thought everything was good.  2 weeks ago the truck started doing some hesitating.  Maybe once every 4 days or so. Then started doing it more will throwing the CEL, P0121. The truck would die and then once the idle was low would act like nothing happened.  I took the APPS back and got a new one.  Then notice while it was hooked to a computer that the throttle at full would only register 64% to 68%.  The Quadzilla would only see under data logging would only see the same.  I tried a third APPS sensor i borrowed from a 2003.  Still it would only see up to 68%.  I was told to put in a Timbo sensor.  I did and now i have not have any CELs but still the truck never sees full throttle.  Has anyone seen this happen before?  Am I missing something i should have looked at?

 

Thanks

Matt

[Me78569]

have you done an apps reset / relearn?

 

 

[Mopar1973Man]

I would do a new Timbo and the do the APPS relearn then you should be set. Ditch the electronic sensor like Stock APPS or the Wells APPS. Timbo's APPS it completely mechanical and no electronic.

 

 

[mz832002]

I did the reset on the factory sensors when i installed them.  I just did the reset on  the Timbo sensor.  Same thing.  When the throttle is pressed at 100% the ecm is only seeing 64%.  I did take notice on the computer it will jump above 64% while being pressed but come right back down and stop at 64%. 

 

Thanks

Matt

[jlbayes]

So you need to verify with a dmm and an actual scan tool the ecm is only seeing that percentage.

[mz832002]

The Auto Enginuity software also verify that the ecm is not seeing 100%.  When graphed it will go above 64% but come right back down and stop and hold 64% throttle.

[Me78569]

I would check the 5v source to the apps wire. I don't know if the apps draws more amps when you go higher on the pedal, but it almost sounds like the power feed is not getting good connection or something.  I would prob the ecm to apps wiring with a multimeter.

[mz832002]

Ill double check that i did it all right.  The other week i check the volts and got 4.8.  I then checked the continuity to the ecm. Ill let you know if i find anything. 

[mz832002]

The trans finally quit so it is solved for now.  lol

 

[Dieselfuture]

Sorry to hear that, time for upgrades