not your typical APPS problem

[24vcole]

hello everyone i have a 2001 24v cummins and am having a lot of problems trying to figure out my dead pedal situation. 

It all started a couple months ago where I would get dead pedal and a surging in the rpms. I changed the APPS  and set the voltage to 0.420v and my surging problem went away but now i have dead pedal A LOT! Iv checked wires and grounds. I cleaned all the grounds and changed some ends but looking at the APPS sensor wiring it looks like the PO spliced in a wire to terminal 3 and ran it straight to the pcm but also keeping the wire going to the ecm. Iv had the truck for 2 years and no trouble up until a couple months ago so I can't see that being the problem. Any help would be great! 

[Me78569]

Is it a stock style apps?  If so you should not set those to voltage as they have a multi part system for knowing when at idle state. 

 

 

 

[Mopar1973Man]

Be easier to just replace it now being the voltage adjust does nothing but make things worse for a old APPS sensor. It based on voltage on when the ECM uses idling software to throttle software. So when you adjusted the APPS you shoved the range to far up now it dead pedal because you've gone out of range and hence to protect you from a stuck WOT the ECM just drops to idle and hold it from a period of time till it see normal signal again. 

 

Timbos APPS no electronics.

 

I've got Timbo's APPS in stock that are fully mechanical and have no electronics. No voltage to set really. 

 

Edited August 4, 2020 by Mopar1973Man

[24vcole]

Yes it is a stock replacement apps. It came with a bellcrank assembly and when I put it on it was worse then before I replaced it. So I checked the voltage the way it came and it was at 0.746 wich from what iv read is way to high. Thats why i brought it down to 0.420 and it helped a lot but still not right. It only screws up when I come to a stop sign or after full throttle. And I could drive for an hour and have no issues park to get fuel and boom screwed up again. It'll never screw up when I'm driving tho, only when I let off.

and the apps that came on the housing didn't have a voltage tag on it either thats why I just set it to 0.420

[Me78569]

You can't blindly set apps voltage, they are calibrated by the manufacturer.

 

My guess is you set the voltage way to low and you are having to increase tps to ~10-20% before the IVS ( Idle validation Switch) is disabled and fueling occurs.

Edited August 4, 2020 by Me78569

[24vcole]

1 minute ago, Me78569 said:

You can't blindly set apps voltage, they are calibrated by the manufacturer.

Well the truck wouldn't even move or do anything the way it was set so I had to try something... I know it wasn't the right thing to do but I had to go to work. So I should try and buy another whole bellcrank assembly or just set it back to what it was when I got it? Or buy a Timbo 

[Me78569]

If the part is bad I would replace it.     Were there codes for the apps?

[Mopar1973Man]

That tag voltage number is the break point between 

                      0.320              0.420

Idling ............................ | Throttling...................... >

 

Now you set it so it rocking back an forth between throttling and idling. It is REQUIRED the idle voltage be BELOW the tag number at least 0.1 volt so you need to set it to 0.320 volts to get back in range again. Idling software disregards the APPS value completely and now runs a internal software of the ECM for idle control. Manual truck have the anti stall feature in the software. The Auto do not have the anti-stall. Adjusting the apps never does any good other that fouling up the idle circuit.

 

Hence there is none of that in Timbo's APPS. You can see the zones in the rheostat.

 

Even on the install of the Timbo they ask to measure the TPS voltage and adjust the stop screw till it rises and then back of to that point it started and the loosen the stop screw 1 more turn to drop the rheostat in the idle zone more so.

Edited August 4, 2020 by Mopar1973Man

[24vcole]

The new APPS didn't come with a tag so should I just try and set it to 0.320 and try it? I know your saying setting it does no good for anything but it was originally set from the store at 0.746. 

[Mopar1973Man]

2 minutes ago, 24vcole said:

The new APPS didn't come with a tag so should I just try and set it to 0.320 and try it?

 

No! Do not set for the old voltage... This why I'm suggesting the Timbo to get you way from this old method of voltages. It was that Dodge APPS has a logic board to control the IVS switch by electronics ot TPS voltage to trigger idle or throttling. This is all based on the current APPS if replace DO NOT ADJUST. Leave it alone! 

[JAG1]

Timbo APPS is the smoothest most reliable APPS available. I wouldn't go anywhere without having one at least under the seat or in the glove box ready to change out.

 

What did the factory APPS cost you these days?

[24vcole]

3 minutes ago, JAG1 said:

Timbo APPS is the smoothest most reliable APPS available. I wouldn't go anywhere without having one at least under the seat or in the glove box ready to change out.

 

What did the factory APPS cost you these days?

Ya i just ordered a Timbo and see if that fixes anything and I bought the sensor and bellcrank together and it was 350 CAD

[JAG1]

You should start reading up on the W-T wire harness mods to lower your A/C ripple. I know you most likely have too much AC volts running thru the system, a slow death to electronics, including the psg board on top of the injection pump. Most all of us have completed this change and all have had excellent results and was well worth the effort.

[jltait]

I just installed the Timbo APPS a week ago, easy peasy!!!. I was getting a code for APPS (don't remember the number, but coincided with what's on Timbo web page). The Timbo APPS got rid of my code, converter lockup hunt, and the occasional dead pedal when I was driving with the cruise set. So far, very happy with the Timbo setup, I hope it works as well for you. I did check for AC leakage at the alternator prior to the investment. 

[JAG1]

A/C ripple can start any time a diode in the alternator goes out. Everything will be working fine so you may never really know when excess ripple begins, but by eliminating the biggest offender to the electronics (the budget minded engineering by the factory). The W-T modifications lower the risk significantly and tests before and after have all shown excellent results.

Edited August 4, 2020 by JAG1