weird fueling issue, with codes
 

99 CTD with 279,000 miles. Unknown if VP44 has been replaced previously (I am 4th owner). Has had Ottomind box on it for a while when I had bought it 30k ago.

Recently it started running up to 1700 RPM all in its own. No matter what I do with the throttle, it sticks there then goes back to idle/pedal position all on its own. If it is doing it and I turn off the truck, it starts up fine, but immediately goes back to the 1700 RPM regardless of pedal position. If it happens on the highway, it can happen around 1800-2000 RPM. So far, RPMs have settled after 20-60 seconds.

Once the RPMs run up, it throws P0252 and P0253. Its also thrown P0251 once as well. No other codes.

I checked APPS voltage and it is fine across the pedal range, I reset the APPS, adjusted the voltage to label specs. Alternator and batteries replaced 18 months ago. Starts fine and no obvious electrical issues.

Fuel pressure is 12-14 psi in all cases. Filter is dirty, but not clogged.

When the RPMs go up on their own, the throttle and cruise cables are loose, so nothing weird there. Also, my scan tool TPS readings do NOT change when the RPMs run up on their own.

I am not sure if the Ottomind is going bad (will check by unplugging the box) or if it is the VP44 or the ECM.

I have not found any reports of this behavior before so I am lost. I can't afford to buy a VP44 if that is not the problem.

sounds like the VP to me:humm:

So have you seen/heard of this behavior before? Its just strange that I can't find any info on it. Thanks for the feedback

Re: weird fueling issue, with codes
 

It's hard to know without running pump in standalone. It will eliminate the trucks electronics. If the problem continues its a pump issue.

So I spent some time today diagnosing the Ottomind module that is part of the Banks Power Pack. It looks like the module is going bad as disconnecting the pump wire calms it down.

I have unplugged the power pack harness from the main harness and while I don't ahve any gauge any longer, the truck appears to be running fine. I won't have the same drive-ability as with the module, but it works!

Will be sending the unit back to Banks to see if it can be repaired.

Re: weird fueling issue, with codes
 

I would reground the Ottomind 90% of the time it will solve your issues.