Archived water/bad tank of fuel? feels like vp44 dying?

[BHubbard]

I filled up last night about 29 gal. ,on the way home it cut out once and had a slight hesitation while driving. The next day I replaced the fuel filter and drove a few miles and it started acting up again,after turning around and driving back home it died going up the hill.

I returned with some diesel 911 and followed the directions and drove home,

I bypassed my fuel guage and placed a guage at the injection pump,18 psi at idle and around 15 at 1500rpm, just as my guage read while this was happening.

I have been driving around the neighborhood doing tests, once the check engine light came on, after I cleared it, the truck would run a little better but still miss or run on for a sec. not outright stumbling like when my vp-44 did fail.

Anyone have any thoughts,maby my tankfull is really bad?

when I went to get filters this morning,I filled up my gas truck at the same station and I noticed they were out of diesel. maby I got the last tank?

If so what to do? drain the tank or a lot of some kind of additive??

 

[Sticks]

What was the code the Check Engine light came on for? How did you clear it?

When you changed your filter(s) was there any gunk/debris/water in the filter housing?

Is the fuel clear or foggy?

Any performance mods - Chip, tuner, etc... ?

With the engine semi warm (above 140*) and in neutral, depress the throttle all the way to the floor and hold it there for a few seconds (you won't hurt it). Does the RPM ramp up smoothly and quickly, or hesitate? Any white smoke?

Will is hit full RPM and hold smoothly?

 

[Missouri Mule]

Was the 15 psi at 1500 standing still or moving?

 

[BHubbard]

I have been testing it all day now, so far the fuel systems seems ok,

as I was driving it around the block the following things happened;

I got dead pedal for a moment,then revved back up,

without depressing the pedal at all it started revving all by itself,like I were tapping the pedal to revv it up as if I were showing off,the water temp guage went back and forth a few times,

I parked it and shut down,started it and it would do the revving thing again.

So I have been checking all of my sensors map, Iat ,coolant, so far so good,

everything has 5 volts and a ground,

I got to the apps and it has 5 volts,I am not sure how to check the sensor?

If I had a code reader this would be easier maby,my truck will not drive anymore.

anyone near me have one?

I will check some threads on the apps. . ???

 

[Wygate]

Have you checked the fuel visually? What did it look like/ clear yellow (think mountain dewish) is good fuel. My ordeal with fuel was cloudy and full of "crap".

If you dont have a better way I use a fuel/ liquid drain hose that has a check ball in the end, you shake it up and down and will eventually get suction (mouth full not required), I have seen them at parts stores and farm stores for 20 bucks or so.

Good luck

 

[BHubbard]

I just pumped out some fuel,and it looks good.

 

[Sticks]

Your throttle issues are textbook TPPS/APPS.

That however will not cause your truck to die, just go to idle (dead pedal).

Starting with the ignition Key off, turn to on, off, on, off, and back on again then be ready to write down the codes that appear in the odometer LCD. Time delay between key on and off is typically about 1 second. This should give you your codes stored in the PCU and ECU.

 

[BHubbard]

Ok thank you, It pulled up p 0122 and 1693 done. .

 

[MMeier]

IIRC, the first one has to do with low voltage at the APPS... second one is just a companion code. Sounds like you need a APPS. On number 3 on my '03.

 

[Sticks]

P0122 - Accelerator Pedal Position Sensor Signal Voltage Too Low

That falls in line with the erratic throttle.

An intermittent transfer pump causing a complete loss of fuel to the VP and stalling the engine would show at least a 0216 code.

Has the truck died unexpectedly since your original post?

Have you checked all the items I listed in my first post?

 

[Moose Truck]

Aps...

Ok thank you, It pulled up p 0122 and 1693 done. .

From Tool's List; https://www.turbodieselregister.com...ine-transmission-faq/96634-24v-code-list.html







P0122 (M) Throttle Position Sensor Voltage Low Throttle position sensor input below the acceptable

voltage range.



P0122 (M) Accelerator Position Sensor (APPS)

Signal Voltage Too Low

APPS voltage input below the minimum acceptable

voltage.



APS would be my Diagnosis. Try this 1st,



APPS - Adjustment - Dodge Cummins Diesel Forum

 

[BHubbard]

The fuel looks good, no electronic mods, I was able to clear the engine light by disconnecting the battery,then it died again and the engine light came back on.

I did not do the full throttle test ,when I was warming it up the other symptoms came up.

I am searching around now to see where I can get the new apps, its already on the bench and looks like the original,192000 mi.

 

[Sticks]

I just read a thread here not too long ago about after market APPS sensors and adapters. OEM is way expensive.

I suppose it is possible that the ECU read a weird voltage and shut the engine down as a safety, but I have never heard of that.

Weird.

 

[DFerverda]

Here is a post about timbo's apps I just put one in a couple months ago, works great.
https://www.turbodieselregister.com...5-kudos-timbom-his-apps-replacement-part.html

 

[BHubbard]

I have a new williams apps, and a obd 2, and have read many posts,
the directions that came with the apps, and read issue 66 pg. 30.
this all makes sense to me, and It still won't run right?

I am using a digital high end meter, tests at pin # 3 at the apps, and pin #23 at the pcm,
they link together no problem. The williams has no voltage tag on it like the stock one did 0. 575 . the lowest the new one will go is 0. 614 ,is this why the pcm won't read the new one? no mater how many times that I run the tests/instructions foe the new apps,
it always goes back to to high voltage at apps ,when its ok and I start the truck.
Then I will erase it with my obd 2 and re run, kind of like an insane person except I try to set it a little different each time.
I am going to try again in the morning, anyone have any thoughts? Do the new apps units have a sweet spot voltage that we are looking for?
Am I insane? low dc volts for a throttle body control can be a trip.

 

[JLandry]

I got dead pedal for a moment,then revved back up,

without depressing the pedal at all it started revving all by itself,like I were tapping the pedal to revv it up as if I were showing off,the water temp guage went back and forth a few times,

I parked it and shut down,started it and it would do the revving thing again.

If the engine is revving up on its own (without you touching the accelerator pedal), that's a strong indication of a problem lies not with the TPS (Throttle Position Sensor) but with the VP44 or ECM.



The TPS is designed to be failsafe in that it has TWO separate built-in "idle validation switches" which tell the ECM it's at idle no matter what the rheostat portion of the TPS is saying. In other words, even if the rheostat portion of the TPS tells the ECM to go to full rpm, that's overridden by the two idle validation switches which tell it to stay at idle. Three components in the TPS would have to fail in unison for the engine to rev up uncommanded. The simple way the TPS is constructed, this is *extremely* unlikely. Therefore, applying the principle of the simplest explanation is usually correct, your problem points to a dying VP44 or a malfunctioning ECM. In order of probablility, VP44's fail much more often than ECM's.



BTW, besides a faulty TPS, that P0122 DTC can be caused by a malfunctioning ECM.



So what to do next?



Well since you've eliminated just about everything else, you may want to read the VP44 diagnostic help on the Blue Chip Diesel web site and go from there.



Good luck,



John L.

 

[Sticks]

If the engine is revving up on its own (without you touching the accelerator pedal), that's a strong indication of a problem lies not with the TPS (Throttle Position Sensor) but with the VP44 or ECM.



The TPS is designed to be failsafe in that it has TWO separate built-in "idle validation switches" which tell the ECM it's at idle no matter what the rheostat portion of the TPS is saying. In other words, even if the rheostat portion of the TPS tells the ECM to go to full rpm, that's overridden by the two idle validation switches which tell it to stay at idle. Three components in the TPS would have to fail in unison for the engine to rev up uncommanded. The simple way the TPS is constructed, this is *extremely* unlikely. Therefore, applying the principle of the simplest explanation is usually correct, your problem points to a dying VP44 or a malfunctioning ECM. In order of probablility, VP44's fail much more often than ECM's...

Nothing personal, but I gotta call BS on that statement. Possible it is a VP issue, but very unlikely.



When mine went TU, it took it a year to do it, and would not throw codes, or duplicate the condition when I took it to the dealer.



Exact same problem, foot off the pedal, and the engine would start revving up (or accelerating on those fun times I was in traffic and in gear), or would be an erratic throttle response with my foot on the pedal holding speed.



I started a thread many a year ago called "anatomy of a TPPS" or something like that. There is another thread started with almost the same name, but the same details, pics of a gutted sensor and theories as to why they get flaky and fail.



And of the three sensors that I have replaced on customers vehicles... same symptoms, 2 with codes, 1 without. None had VP problems.



OBDII scanner or DRBIII connected would show erratic TP values while nothing was touching the pedal.

 

[JLandry]

OBDII scanner or DRBIII connected would show erratic TP values while nothing was touching the pedal.

THAT we can definitely agree on.



John L.

 

[BHubbard]

I am still confused about the problem?? I did go to chips web site and call, we are playing phone tag now. I need to t-shoot this correctly now as I can barely afford one part,is it the pump or ecm? or am I missing something with the new apps install? It is not throwing any codes related to the pump, mainly high voltage codes to the coolant sender,the map sender,and the new apps,, the ecm and pcm will throw a generic code and erase easily. ??
A local shop replaced my pump about 75k ago, not sure of the quality, I will do this one myself if it is the pump. hopefully not,
Is removing the ecm and taking it to a shop a option?? and can it be bench tested??

 

[JLandry]

or am I missing something with the new apps install?

Since you've installed a brand new Williams TPS, that should effectively eliminate any concern about the TPS being a culprit in this problem... you can move on to other things. I'll assume you calibrated the new TPS to the ECM after installation as this need to be done anytime you replace the TPS, the ECM, or if you turn the ignition key when either the TPS or ECM is disconnected from the wiring harness. Please note that this TPS "learn" procedure is NOT the cause of your problem... it's just something that needs to be done to improve drivability.



Just in case you need it: To calibrate the TPS to the ECM, turn the ignition key to the RUN position (do not start the engine), then slowly depress the accelerator pedal to the floorboard, slowly release it, then turn the ignition off. That's it.

It is not throwing any codes related to the pump, mainly high voltage codes to the coolant sender,the map sender,and the new apps,, the ecm and pcm will throw a generic code and erase easily. ??

We could be of much more help if you'd post each and every trouble code you've been getting no matter how unimportant you think they are. Sometimes multiple trouble codes taken together can reveal the big picture.

A local shop replaced my pump about 75k ago, not sure of the quality, I will do this one myself if it is the pump.

Based on the symptoms you've posted and the fixes you've done so far, and the mileage on your current VP44, my opinion is you have a failing VP44... sorry for the bad news! VP44's fail much more often than ECM's, so lacking any other solid evidence to the contrary, the law of probabilities points to the VP44. They do fail regularly without ever offering up a trouble code.



Cummins has a VP44 tester (part number 3163834), which is a simple electronic box used to verify whether a VP44 is working properly on the vehicle. It connects directly to the VP44 and the vehicle's battery after disconnecting the wiring harness (thus completely bypassing the ECM). If the VP44 is working properly, the engine can be started and will idle using only the Cummins tester. The Cummins tester will also verify the VP44's high idle feature. If the VP44 is able to operate properly using the Cummins tester, then you can look elsewhere for the problem (at the ECM, wiring harness, etc. )



Any Cummins service center should have this tester.



In the past I've read posts here on the forum where others have said they were able to wire their VP44 directly to the vehicle battery in order to effectively duplicate what the Cummins tester does but using only a few wires and some alligator clips... but I haven't tried it myself. Possibly you can do a search and find this info.

Is removing the ecm and taking it to a shop a option?? and can it be bench tested??

Yes it can be bench tested, but it takes specialized equipment which you're not likely to find locally or at a Chrysler dealer. A place that specializes in rebuilding ECM's like Auto Computer Exchange in Florida can do it. However, some Cummins service centers or any Chrysler dealer (or someone with a Miller SPX DRBIII scan tool) can run basic tests on the ECM with it still installed on the truck to check for certain malfunctions.



Best regards,



John L.