Engine/Transmission (1998.5 - 2002) APPS from Cummins

[Batphreak]

Ok, so I swear I got a price from Cummins on this before, but I must have had something wrong. Not sure what's going south on my truck but if I replace the VP before trying the APPS then find out it's the APPS I'm going to be really mad at myself. So, I called a Cummins dealer (Peterbilt in Pewaukee), gave them this part number:



4002066



got that from this site:



dodgeram.org



The guy tells me $39. 56. I gasped, "I thought that was supposed to be a $300 part??!" He told me, nope, I know some for Cat's have been that expensive, not this one. So, I had him order one. I'll give it a try without thinking for that price. Did I order the wrong freakin part, or has the whole world gone crazy??

 

[Bob Wagner]

you ordered the crank sensor. why throw parts at it? have it scanned for codes

 

[PC12Driver]

What symptoms does your truck have?



And make it easy on yourself, get your engine number off the data plate (front driver's side, on the gear case next to the injection pump) and use that when you order parts. That's the number that the Cummins parts lookup software uses to get the exact fiche for your engine. Much more effective than scraping part numbers off the internet.

 

[Batphreak]

Here's a rundown of symptoms and diagnosis so far:



https://www.turbodieselregister.com/forums/showthread.php?t=165202



Still no CEL, dead pedal is getting a little more frequent now. I get it after I've driven the truck a good distance, then let it sit less than overnight, it'll go dead for a while heading out of a parking lot. Sometimes I get it cruising at about 35mph in 3rd. Still very predictable if I hit 57. 5 in O/D it'll fuel up and take off, never get dead pedal above 57. 5. I don't have an APPS code yet, or P0216. That's why I'm about to the point of throwing parts at it. That and just wait 'til it leaves me sitting, then I'll know what's gone bad.

 

[Bob Cochran]

The last time I was at Cummins I gave them the engine number, etc of the nameplate. The parts guy was nice enough to print out I guess you would call its build information. Things like where and when built but the best thing was it had Cummins part numbers for a lot of the major items on the engine. Nice to have around.

 

[PC12Driver]

The code for the APPS gets set when the voltage is out of range. If it remains between the known high and low voltage, it could still be noisy or have dead spots and not set a code and trip the CEL.



Try fanning the accelerator pedal to the floor and back a bunch of times before you start up again. This may clean some of the dust/corrosion off the APPS brushes and give you a semi-clean signal for a little bit. If you get some throttle response back then this points to your APPS. This is what helped me diagnose mine (at 80-85k miles iirc). I had a surge that would go away for 20-40 miles after I worked the pedal, then it would creep back.



Or, with the truck in neutral, slowly and smoothly depress the accelerator pedal to the floor and watch for hesitation in rpm (most likely right about the same rpm that you sit at when your doing either 35mph in third or 57. 5mph in OD - which is probably about the same rpm, right?). The APPS will wear at the point where it spends the most time (and since the APPS directly controls RPM on our diesels, that point should be about the same pedal position either unloaded or lightly loaded/cruising).



Two other things that make me think its the APPS; you don't get any symptoms as you depress the pedal past cruise (since the brushes are hardly worn up there) and the problem is getting progessively worse (more wear and brush dust build up).



But I could be completely wrong, too.

 

[sootgrinder]

Mine had dead pedal, no CEL, ect. Warranty replaced lift pump (made it worse), turbo and wastegate (made it even worse), and finally the IP (all better now).



Sorry, but sounds like another IP is dying.

 

[Batphreak]

All right. Called 'em up with my ESN, yup, had the wrong part number. The correct one is: 3970084, I e-mailed the website just to let 'em know, doubt it'll do much good, that's the first bit of wrong info I've gotten from that site though. Anyway, PC12, thanks for those suggestions I'm definitely going to see what I can scare up, I really hope I can get away from this problem without it being the VP (even though I know that'll come one of these days). It just seems to me that this problem would be far more random if the VP was going. I'll let ya'll know what happens.

 

[Batphreak]

Well, tried working the throttle up and down before starting a couple times, didn't seem to help anything. I revved the engine in neutral to see if there is a dead spot, I believe there should be one (if APPS is bad) at about 1500 or so RPM, there really didn't seem to be a dead spot. So, I don't know. Should I try replacing the APPS just to be sure, and because it's a lot cheaper than the VP, or is it time to give up and throw a new VP at it? What would you other 24-valvers do out there?

 

[gregdoerfler]

i have never had the dead pedal but for the last few years when it would get colder out about 40 when i accerate the throttle would be a little jumpy not smooth till i got on the throttle more, i was blaming the vp but i had to change the vp because a wire shorted and burned up the pump, now that it is getting colder here it is doing it again so i think it is my apps. the apps is alot cheaper then the vp if you are going to throw parts at it.

 

[pro99]

Get a VP44 on the way!

 

[CSnyder]

I will bet money its your APPS and not the VP. Get a mechanic to hook up a scanner and ride shotgun and watch the voltage to the APPS while you drive with your foot steady... guaranteed it will jump around between 11 and 19 when you are cruising at your dead spots with your foot steady on the skinny pedal. I just picked one up this week from the dealer for 300. 13 with tax included.



Chris

 

[pro99]

Do you have a auto or manual trans? If you have a APPS dropping out your lock up will more likely go in and out! Does the truck fall on it's face when the dead pedal happens or keep speed? If it keeps speed more or less then your looking at a VP44! But hell if you want to try out a APPS or buy one I have a new one for sale 250. 00 plus shipping?

 

[Batphreak]

When I get dead pedal it does more or less keep speed, it adds just a tiny increment of fuel, it will very slowly gain speed on a level surface. It falls right on its face if I hit a hill. If I'm on a level surface and gain speed to that 57. 5 mark it will add all the fuel my foot was tyring to give before and act like nothing was wrong. I'll have to see about getting a Chrysler reader hooked up to it.