Ecm and Dead Pedal issues

[mowmaster06]

I am desperate for any help. I have a 1999 Ram 2500 5.9 Cummins, and when I first bought it, it had delayed wait to start. I didn’t know what this meant at the time, but it wouldn’t start at all after a week or two. I put in a loaner ecm and it started up great, and runs okay. 
 

Three months later, I’ve rebuilt the original ecm twice, and still nothing. Loaner ecm is still in and working, but seems to have developed some dead pedal. Hot or cold, after 40-50 mph, it only accelerates through the gears slowly after that, even if I mash the pedal. 
 

Could it be excessive AC noise killing them? Or two bad ECMS? Awesome truck, but I don’t want to dump thousands of dollars down the drain. 
 

any help would be appreciated. 

[Tractorman]

A "dead pedal" symptom is the engine dropping to an idle and staying there. What you are describing is likely to be the ECM commanding the engine to operate in a "de-rate" condition.  This can be caused by many things, but not likely to be the ECM.

 

Need to know if you have any trouble codes displayed.   This would greatly help with what direction to go with diagnosing.

 

If there are no trouble codes set, then I would start looking for mechanical issues.  Take your time - don't focus on just the ECM.

 

- John

[mowmaster06]

Soon after I bought it, I had the P 0216 code, and didn’t think anything of it because I was unaware of how serious that was. I will check again in the next few days, but could the gradual limited peddle be caused by the vp44 failing? 

[Tractorman]

41 minutes ago, mowmaster06 said:

but could the gradual limited peddle be caused by the vp44 failing?

 

The P0216 code is related to injection pump timing - usually a fault inside the VP44 fuel injection pump.  When that code sets, the ECM will likely de-rate the engine output.  So, yes, that code will most likely be a VP44 pump failure.

 

Before condemning the VP44, verify that you have at least 5 psi lift pump fuel pressure, especially at higher engine loads.

 

- John

[mowmaster06]

“Before condemning the VP44, verify that you have at least 5 psi lift pump fuel pressure, especially at higher engine loads.” 
 

The previous owner claimed he replaced it, and it also has a Fass fuel system on it. How would I test that? I know my way around a gas engine, but new to diesels. 

[Tractorman]

2 hours ago, mowmaster06 said:

The previous owner claimed he replaced it, and it also has a Fass fuel system on it. How would I test that?

 

There should be a test port located on either the fuel filter housing or the VP44 inlet port.   A 0-30 psi gauge would be suitable for the test.  If there isn't a test port available, there is an aftermarket banjo fitting with a 1/8" female pipe port that will replace the fuel inlet fitting on the VP44.

 

A lot of VP44 truck owners either have a dash-mounted fuel pressure gauge or a low pressure warning light for the lift pump.

 

- John