Customer called me yesterday asked if I could tow their truck in and see if I could figure out what's wrong with it! It's a 99 2500 2wd auto with stock 24v new lift pump and reman vp44. The truck starts and lopes hard with no throttle pedal. No engine codes. Anyone have any ideas? The vp44 was put on about 4 months ago and it's been sitting at another diesel shop for 3.5 months. I don't know where to start!

Check the apps voltage and zero it in?

I've checked the apps. Zeroed it in. Getting good readings on it. Any suggestions????

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The truck is running a little longer now. Still won't build any throttle! I did get the code for low voltage to apps now. So I replaced the apps with a spare one that I have for another truck and it still doesn't help.

Loping is a fuels system issue typically. I would back track all the injectors, cross over tubes, injector lines, etc. Even might have to change the VP44 and see if it changes.

That's the crazy thing....another mechanic just put this vp44 on Sent from my DROID RAZR using Tapatalk 2

That's the crazy thing....another mechanic just put this vp44 on Sent from my DROID RAZR using Tapatalk 2

But is it the right pump? Is the pump used maybe? The only way to rule it out is to swap and see...

The first mechanic to work on it was a Ford mechanic. He put the pump on but supposedly left the key out! They had it towed to another mechanic who supposedly put the right key in and it developed this problem. He told the owner to get the truck away bc he doesn't know what's wrong with it! The pump is supposed to be remanned.... I will take it off and send it back and see if they will give me another one. I doubt it though since I will be the 3rd one to work on it! Sent from my DROID RAZR using Tapatalk 2

The first mechanic to work on it was a Ford mechanic. He put the pump on but supposedly left the key out! They had it towed to another mechanic who supposedly put the right key in and it developed this problem. He told the owner to get the truck away bc he doesn't know what's wrong with it! The pump is supposed to be remanned.... I will take it off and send it back and see if they will give me another one. I doubt it though since I will be the 3rd one to work on it! Sent from my DROID RAZR using Tapatalk 2

Sounds to me like you might want to check the timing marks on the gears. If you don't bother the gear when you remove the VP it is fine but it is possible if the other guys working on it didn't get any information and just tore into it they may have tried to take the gear out with the pump and in that process got the gear timing off. I have heard this cause a lope in a diesel before with really poor or no acceleration. It was not a Cummins but I'm sure it is possible. Sent from my DROID BIONIC using Tapatalk 2