Intermittent dead pedal.

[Doug Dear]

I have the pedal issue. It will go a mile or two and lose the pedal. I can turn on off the key and it runs great. I checked for continuity of the wires and they were good. Low voltage less than 2 volts at the apps.  It has a new apps sensor and the Ecm was checked out and was good and the  Pcm was rebuilt 50 miles ago. Along with a new vp44. I am checking grounds but I am at a loss. Any ideas?

 

[Mopar1973Man]

Error codes?

Did you get a Timbo's APPS?

 

What does a live data tool show for signal? 

 

As for grounds do the W-T Ground wire mod.

 

[Doug Dear]

Yes, i got a timbo. My scan tool has a the live data on it. But as of right now i have the truck apart. The computer i had tested is out and i have already begun the WT ground and thats all apart. So thursday I should be back at it. I thought about opening the bundle all the way to the ecm. Maybe there's a bare wire i doubt it. But what a mess that will be. The only thing that keeps bugging me is why when i turn the key off then on, while it is rolling, it runs like a top. That means its can carry voltage but its not getting a signal. Trust me I have been watching scanner Dan Videos. Trying to find that 5 volt reference. 

Edited September 17, 2020 by JAG1

[dripley]

FWIW when my oe VP went out I could most times shut it down, restart and it would run fine for while and then wig out again. I could do this while coasting down the road. I am in no way saying your VP is dead.. It sounds like yours maybe too far taken apart for that to be done now. The trouble codes are an important part of finding your issues. The don't necessarily point to the exact issue but the hints they give would be of great benefit.

Edited September 17, 2020 by JAG1

[Doug Dear]

I am going to have it back together friday. And ill see what codes come up. The po122 was what it had. But i have thought what if it is the pump. It has only 100 miles at most on it. It is a thoroughbred diesel 2 year warranty. And the computer on the pump is brand new. I called and asked they told me new computer. But anything is possible. 

[dripley]

I only reason I brought this up because without codes or some common symptom It is hard to diagnose what the problem is. I hate see folks spend money on things that might not be the issue. Some of these parts are quite spendy.

[Doug Dear]

I agree. Let me give you some history. I bought this truck in 2001. Replaced the pump in 2014. Then last year the apps started its stuff. I talked to some guys on a forum they told them what was happening. They told me man its your apps sensor. I go buy a 50 dollar one. I mean its got 300,000 miles i figured it probably was out.  Didn't fix it. Working 12 hrs a day no time so i took it to a shop 2 months they couldn't figure it out took it to another shop. They said it was the pump. I replaced it. I picked the truck up he told me the alternator wasn't charging i sent in the pcm. One shop or the other hooked the battery backwards and shorted it out. So i got it back it was running fine about 50 miles it started again. I had shoulder surgery so i couldn't drive it. That brings us till now. Because I have the time I am trying hunt it down. I wrote down the codes, po 222 apps voltage and po216 fuel injection pump timing failure. I could be a fuel delivery problem like a lift pump I have a fass, but that would not explain the low voltage to the sensor.

Edited September 17, 2020 by JAG1

[Mopar1973Man]

2 minutes ago, Doug Dear said:

po216 fuel injection pump timing failure.

Lack of lubricity... If pressure is good then the lubricity is too low and bound up the timing piston. 

[Doug Dear]

That means what? Lift pump? What about the voltage being low. I read a article by blue chip diesel. Its stated get an analog meter hook it up and run it in side the cab and drive it. If the voltage stays the same then its the pump. I only have a digital meter. Ill have to read it. Make sure i got that right. 

[JAG1]

Just a hint of help from me....by putting 2 stroke oil in the fuel it will help lubricate the timing piston which typically is the first thing to  go on the Bosch VP44. About an ounce per gallon will get the fuel lubricity within Bosch specs by lowering the scoring value.

[Doug Dear]

2 stroke oil. I didnt know that.

[Mopar1973Man]

1 minute ago, Doug Dear said:

2 stroke oil. I didnt know that.

Here you go... My decade long study...

 

 

[JAG1]

DD,  this is just a small part of what it's all about to become a member here. Why don't you join up? 

[Doug Dear]

How do you join up?

[dave110]

At the top of the page there is a 'subscriptions' tab. Click that and choose what you want. It's about the cost of a cheap case of beer, and with the time you save working on your truck you'll have more time to drink beer 

[Doug Dear]

Its done. All joined up. 

[dripley]

Sounds like you need to talk with T'bred about your pump.