Hello, I'd like to thank you all for already teaching me so much. This time I'm in quite the bind it seems.My problem started about 6 months ago with what came to be a small surging while maintaining moderate speed ~ 40 mph. I thought it was my foot shaking a bit and thought little of it. 2 weeks ago the surging was terrible and started in the morning while leaving for work. I limped home idling in granny gear up hill the whole way.Original code was 0122, so I replaced the APPS with one of Timbo's. Problem not solved. I also replaced MAP sensor from Cummins and ordered the adapter from Geno's. Checked the wires and grounds and things appear good. Finished installing the gauges just today and they appear to work ( big thanks to mopar1973man for the boost location). I went with the Vulcan line and it went in smooth on the fuel gauge. But I digress...Current codes are 1693, 0236, 1475, and 0122. The truck starts and idles fine but acceleration is SLOW, like 2 seconds to get to 2000 rpm, parked in neutral. I can wind it up as far as I want but can never hear the turbo spool while revving parked in front of the house. The gas pedal seems like it is either "on" or "off" and I cannot maintain a rpm level. When I try to maintain, I fall back to idle with the customary, at least for me, hiccup at return to idle. Fuel pressure is 9 psi at idle. Power is gone - can't get out of second without stalling. Both fuel pumps were replaced in 2007 and have about 40k on them.I failed 2 tests while running through the code diagnostics (thanks a lot for those - very helpful) in that for 0236 #9, my resistance is 36k ohm, much more than the 1000 ohms max, and for 1475 #3 my voltage is 5.04, less than the 5.2 threshold.It looks like I need a new ECM unless anyone out there can think of something else to check or if there is a bit of wiggle room on the DVOM. I appreciate your time in this long post. Please let me know.Phil

Mine acted very similar when the ECM crapped out. It would idle but surge like it had a mind of its own,rev very slowly no matter how far you pushed the throttle, and a lot more codes than you have. Pretty much undriveable.I would think it is the ECM, but lets see what some of the other folks have to say. I like all the confirmation I can get when a part is that pricey.

Is the Timbo APPS the one that you supposedly do not have to calibrate? I guess my question is, if it required calibration, did you follow the steps properly? How about battery voltage? Your not over/under charging your batteries while the truck is running?Anytime I see improper voltage like you are seeing I try to eliminate the possiblility of a battery/altenator malfunction or poor ground connections before condemning any components.

I tend to want to follow diesel4life for the first part in double checking everything before even thinking of buying a ECM. Make sure you not fighting a wiring issue, alternator or something else.

I believe I calibrated the APPS correctly - disconnected the batteries and left the ignition "on" for 30 minutes plus, then reconnected the batteries and slowly pushed depressed and released the pedal. I have tried this three times, hoping that I was making a mistake in the APPS calibration. :banghead:I believe I forgot to mention that I did replace the alternator when I thought I was getting 30v AC feedback from the alternator!! I later learned from this forum that my brand of DVOM is a cheaper model and they mis-read this. I charge at about 14.1 volts and have about 12.1 volts when the truck is off. Interstate batteries are about 2 years old.I cut a bit of insulation from the ECM ground under the driver's side battery tray and found the wires were in pretty good shape - still copper in color. I sanded the copper contact surfaces and re-attached. I also cleaned ground contacts on the body near the radiator and firewall. I checked a few of the fusible links(?) that come from the passenger's side battery, which I addressed two years ago when my dash gauge cluster went dead. I also cleaned the ground that attaches to the lower front driver's side of the block. The battery posts have been brushed.Should someone in my position go ahead and cur a few inches off the ground leads and rebuild the ground contact? Is there a diagram of all the grounds to look at? Should I go ahead and pull off all the tape and bundling from the wire harnesses and perform a FULL inspection? Should I pull the ECM and clean the contact between it and the block?Thanks a lot for your time - it would be nice to not have to buy a new ECM.Phil

If you put a Timbo Apps on you need to physically check and set the voltage on it, in your last post you recited the calibtation for the factory apps this could be your issue, the Timbo should have came with detailed instructions on how to calibrate it as the factory apps calibration is different from the Timbo, the Timbo is a set it and forget it nothing to relearn like the factory one.

I did find my original APPS voltage at first install, tighten the screw until voltage increased, then back it off half a turn if I remember right. I kept doing the pedal thing with all of the hooking and unhooking of the battery with the gauge install hoping something would change. I will check it again.Thanks for the feedback. Phil

It appears as though I need a new lift pump which will be done asap. Idle pressure is 9 and jamming on the pedal drops the pressure to 4 psi. The air in the line as recommended by ISSPRO wouldn't cause low readings by this much would it? This may be a dumb question, but could the lack of fuel be throwing my codes for the APPS and MAP sensor?Please let me know what you think.Thanks.Phil

Your VP will be much happier with good fuel pressure and last longer. As far as MAP and APPs codes, I would not think the fuel pressure would have anything to do with it.

I had the old girl taken to the shop and the diagnosis was a intermittently failing lift pump (stock replacement) that in turn fried the VP$$. To test their theory, they threw in a Carter lift pump they had laying around and the dead pedal, very slow acceleration while in neutral, greatly improved. They said the fried VP44 computer was causing the codes mentioned above to be thrown.I have a BD VP44 on the way and am going Airdog 100. The word on the web is that the new BD VP44 can add up to 100 hp (!). With this possible power addition, I have a few questions:- Do I need to add larger turbo and injectors to accomodate the new pump? I drive like an old man but do occasionally tow heavy loads over mountainous terrain.- I'm not a hot rodder, so is the pump for me? If I don't blow it out from time to time, will the pump be affected by not being exercised all the time?- Can i expect higher exhaust temperatures?- Is the Airdog 100 sufficient for this higher possible flow?- Is there anything else I should have my eye on?Any opinions are greatly appreciated.Thanks a lot.Phhil