02 Intermittent dead pedal

[Ironforger]

Hey Fellas,

 

02 cummins 3500 dually 6 speed

 

Intermittent dead pedal. Sometimes while driving it sputters bit or it doesn't accelerate,  does not stall out, it's just kind of runs flat and pedal does not respond as it should. Intermittent. No rhyme or reason. Some days it's fine, other days seems like it only happens for the first 15 minutes after starting when the truck is cold.   It kind of feels like when my APPS failed a few years ago.

 

Could my issue be as simple as resetting the APPS? Have not tried that  yet.

 

More info:

Current mileage:  250,000

Installed new timbo APPS 2018 @ 226,000 miles

 

I checked for codes, got none.  Only shows P - Pcu, P Done, P- ECU, P Done.  Tried a ODBII scan tool,  no codes.

 

I have a fuel boss mechanical fuel pump (installed 2013 / 213,000 miles and fuel gauge so my fuel pressure is definitely good. Always using  TC3w 2 stroke as well. 

 

Thoughts and opinions welcome.

 

Thanks!

[Tractorman]

1 hour ago, Ironforger said:

Intermittent dead pedal.

 

Just want to clarify a "dead pedal" occurrence.  This is a a condition in which the engine falls to and stays at idle speed for 30 seconds or so and then corrects itself on its own.  The transition is smooth and no engine miss is involved.  This condition can occur with a faulty APPS, but not limited to a faulty APPS.

 

Another condition that can occur is a reduced power mode (sometimes call "limp mode").  This condition will last approximately 30 seconds or so and then correct itself.  The transition will also be smooth and no engine miss will be involved.

 

1 hour ago, Ironforger said:

Sometimes while driving it sputters bit or it doesn't accelerate

 

This does not sound like a "dead pedal" condition nor a "limp mode" condition.  

 

Have you done the W-T ground wiring modification recommended on this site?  A bit more history on your truck will be helpful - total mileage, mods, how many owners, other related problems / repairs, etc.

 

- John

 

Edited September 3, 2022 by Tractorman
Because I never get it right the first time.

[Hutch24v]

Yeah more history would help. Could be vp44 related and could be a failing MAP sensor. Codes would tell you though. 

[Ironforger]

10 hours ago, Tractorman said:

 

Have you done the W-T ground wiring modification recommended on this site?  A bit more history on your truck will be helpful - total mileage, mods, how many owners, other related problems / repairs, etc.

 

- John

 

 

Thanks for your reply and questions.

 

I'm not sure if I explained it well. I don't know if it is a dead pedal or limp mode or what. I only know it's happening and it's intermittent. I posted a you tube vid link below. Took this while the issue was happening.    

 

The truck currently has 250,000 miles.

 

 

Yes I did the W-T ground mod and B+ 150amp circuit breaker in 2020 @ 232,000 miles.

 

As far as the known history, I've owned the truck since 2013. It had 213,000 miles on it when I bought it.  I do not know much about the previous history or maintenance. I don't know if the VP44 is original or not.  I have not done anything to the pump.  I've done alot of the basic cummins maintenance and repairs, but have not done any performance mods except for a fuel boss mech fuel pump and Southbend Stage 2 clutch.   I always use Tc3w 2 stroke and have been since I bought it.

 

 Other maintenance and service i've done:

 

2013: @ 213,000 miles:  Fuel boss mech fuel pump and big fuel line kit.  All new fuel hoses.  New front main seal. Killed the puke bottle, re-routed crankcase vent, inspected timing gears, killed the killer dowel pin, 

2015: @ 217,000 miles: New high flow steering pump, rebuilt the vacuum pump, 

2018:  @ 226,000 miles  New timbo APPS, BHAF, all new brake lines & brake hoses

2019:  @ 230,000 miles, southbend stage 2 clutch, bronze pilot bushing, rear main seal, 4" stainless exhaust

2020: @ 232,000 miles:  W/T ground mod and B+ 150amp circuit breaker, Water pump, idler pulley, serp belt & cam position sensor (FWIW: the cam sensor wasn't bad, I just replaced it pro-actively)

2020 @ 237,000 miles, removed 4.10 gears, installed 3.54 gears

 

Not much else beyond brake jobs and oil changes etc. As you can see no real performance mods but In the near future I plan to jazz it up a  bit. Nothing crazy. Keeping the factory turbo but getting the Quadzilla, Slightly bigger injectors (50hp?) and an exhaust brake. 

 

Need to get this current issue sorted out before any mods happen.

 

Here is a You tube video I took while driving. If you listen closely you can hear the engine and the issue I'm describing:   

 

 

[Tractorman]

Good information from you.

 

It is not a dead pedal or limp mode symptom.  It sounds like a direct engine miss, as if the signal to the fuel solenoid valve (inside the VP44) is being interrupted.  I recommend that you recheck the work you performed when you did the W-T wiring modification - especially the ground circuit for the ECM and the VP44.  You could also swap out the fuel pump relay in the PDC (power distribution panel) with another relay in the PDC.  The fuel pump relay supplies power to the the fuel solenoid in the VP44.

 

- John

[Ironforger]

On 9/4/2022 at 2:54 AM, Tractorman said:

It is not a dead pedal or limp mode symptom.  It sounds like a direct engine miss, as if the signal to the fuel solenoid valve (inside the VP44) is being interrupted.  I recommend that you recheck the work you performed when you did the W-T wiring modification - especially the ground circuit for the ECM and the VP44.  You could also swap out the fuel pump relay in the PDC (power distribution panel) with another relay in the PDC.  The fuel pump relay supplies power to the the fuel solenoid in the VP44.

 

 

UPDATE:   Issue was due to a bad MAP sensor. Issue is fixed. Truck runs great now as it should.  I replaced the MAP sensor with a genuine cummins part from Genos. (Had to also buy the harness adaptor from Genos for the 02 cummins).

 

Looks like I got the last one Geno's had in stock. Now it's backordered 6 weeks.

 

 

Again, I don't know if I described the issue very well.  It was not a direct engine miss.   Truck started up fine. Idled fine. Intermittently while driving down the road, it would loose power, but not stall. While this was happening, If I stepped on the accelerator pedal, it just kind of did nothing. Wasn't fueling, wasn't boosting, just kind of felt flat like limp mode or dead pedal.   Then,  intermittently I would get bursts of fuel and boost, other times after a minute or 2 it would run fine.  It was doing this crazy ongoing intermittently.  

 

I ruled out the APPS by turning on the cruise control while the issue was happening. Issue still occurred while in cruise control. I read on the cumminsforum that the cruise control does NOT use the APPS, therefore if issue still happening while on crusie control, then the APPS is ok.

 

My W-T ground mod is solid. I was very thorough and detailed when I did it.  \

 

I hope this thread helps others who experience this mystery intermittent issue.

 

I smashed the faulty old MAP sensor with a sledgehammer, then I melted it down into a paperweight in my coal forge.

 

 

Edited September 24, 2022 by Ironforger

[Ironforger]

On 9/3/2022 at 3:31 PM, Hutch24v said:

Yeah more history would help. Could be vp44 related and could be a failing MAP sensor. Codes would tell you though. 

 

Thanks Hutch24v.  Although issue was definitely a failing MAP sensor, truck did not have any codes.

 

Thanks for putting me in the right direction regarding that MAP sensor.

[Tractorman]

On 9/22/2022 at 11:18 PM, Ironforger said:

Again, I don't know if I described the issue very well.  It was not a direct engine miss. 

 

After listening to your video, I think you described the issue very well as an engine miss.   In fact, I would have called it a direct engine miss - just like a gasoline engine with a misfiring sparkplug / plugs.

 

I am glad to hear you solved the problem and it wasn't expensive.  Also, thank you for reporting the final outcome back to us.

 

- John

[Hutch24v]

12 hours ago, Ironforger said:

Thanks for putting me in the right direction regarding that MAP sensor.

Yeah man. I had the same symptoms not too long ago. Glad you’re back on the road again.