I have had this problem for about 2 months now and Im really pulling my hair out now My 2001 will fall on its face when you try to get in the throttle heavy and go to an idle for a few seconds the back and fourth until you let off of the throttle.If you are easy on the pedal it is ok.It may run fine for 3 or 4 days at a time then act up for a day or two.I replaced the lift pump didnt help.I have took it to 2 different diesel mechanics one says E.C.M. and the other says IP but not with no certainty.I took my comp box off and left it off fot 2 weeks now made no difference.Looked for a crankshaftshaft positioning sensor but it dont have one just a plate where its should be.I have a E.C.M. on the way thought I would try the cheapest first.The only code is P1689 (problem comm. between ecm and IP)truck has 89,000 mi
Any help before I have no hair left

 

Welcome!

Well, it sounds like the symptoms of a VP44 failure. Often it is called the "dead pedal" syndrome. You also state you have a comp box so you may have taxed the IP pretty hard. Many of us have fuel pressure gauges to monitor the pressure from the LP to the IP so that there is a constant supply of fuel to the IP.

I don't think the 2001's have a crankshaft positioning sensor...but someone will correct me if I am wrong.

As you go through the process of fixing things, you should plumb in a pressure gauge so you can monitor fuel supply.

Good Luck!

 

I'll take "VP 44 failure symptoms" for $1200 Alex.

 

I'll second that..

 

VP44 or TPS/PPS (Throttle/Pedal Position Sensor), but that's just my .02.

 

Did your mechanic find any codes? If so what were they?

 

check your codes again with the on off on off on method. it will say pcu then done then ecu (this is where youll get the 0216, which is the death code) then done. Make sure you catch them both!

 

Check the codes on dash, if you can't get any other than 1693, you will have to get scanner to read, but don't rush out to buy/borrow one yet. Disconnect both batteries overnight, then reconnect, and reset apps, then see if codes or problems have disappeared.



If codes or problems come back right away, THEN you have an issue to address depending on what codes may appear.

 

Nothing is probably wrong, your engine is just getting some wear on it and you should look into getting a nitrous system to get the power back up.

 

 

OK I get a 1693 with the switch on-off method but I have had it hooked up on a computer 4 times and the code is allways p1689 (problem comm. between ecm and IP)They reset it and it comes back the first time it stumbles.I have tried the battery cable thing several times with no success.Sometimes you can drive it check engine will go off by its self and run fine for a few days.Then the fall and run bad 2 or 3 days.

 

this may sound off the wall but check all of your grounds and make sure you are getting proper voltage to the pcm and ecm. if this problem comes and goes it sounds like a loose connection. but i have found before loose ground will cause all kinds of problems

 

Is that the only code they pulled, wasn't there any more, what kind of scanner did they use?, as a cheapo one will not be able to access any other codes stored.

 

2= advanced autos
2= $8,000 computer(so he said) at big diesel shop
no other codes

 

Like I said this been going on for 2 months.First time it happend was after I ran it really low on fuel.filled it up few miles later it started.I changed fuel filter first thing. Mabee this will help