Issue with engine missing at 1500-1700 RPM?!?! Need help!

[coreyyoung]

So I have a 2001 dodge cummins with the 6 speed manual, it has 50 horse injectors (50k on them) new vp44 (20k on that) the batteries are fairly new. It also has a pacbrake, air dog 150 which was installed before the new VP44 and a holset turbo that pushes a little more boost than stock and it also has a 4 in straight pipe. The issue with this truck is I have a miss and I called the kid tonight and he bought the APPS sensor from dieselsource.com and HE DID NOT CALIBRATE it. He told me he was getting his dead pedal in the same area I said it was missing at. I have cleaned the IAT sensor, probed the ECT and it all checked out good the only codes are a P0500 ( speed sensor signal ) and P0118 ( self created high voltage in ECT sensor while testing it). So tonight I pulled the battery cables followed the steps exactly and after I turned the KEY back off after calibrating it, I started it and idled it up and the miss started at 1200 RPM and went through 1700 and then in a few mins it only isolated to around 1500-1700.So my main question is what can happen if you DO NOT calibrate the APPS, and any advice on this situation would be very helpful. I am about to sell this truck and I NEED TO FIX THIS!Thanks, Corey

[diesel4life]

The apps sensor will need to be calibrated once its installed. I think Ive heard of a few instances where people can bolt them on and be fine but thats just hearsay. Most likely it will be out of spec and you will still have issues such as the dead pedal feel until its calibrated. There should be instructions with the sensor when it comes in the mail. Im sure theres threads in this forum you can look up to familiarize yourself with it, its not difficult by any means to do.

[Mopar1973Man]

Here is how to install and calibrate the stock APPS sensor. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/35-apps-sensor-replacement-procedure Here is how to install and calibrate the Timbo APPS sensor. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/39-timbos-apps-installing Thing is typically APPS sensor won't create a misfire. But VP44, injectors, or low fuel pressure most likely would.

[coreyyoung]

Here is how to install and calibrate the stock APPS sensor. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/35-apps-sensor-replacement-procedure Here is how to install and calibrate the Timbo APPS sensor. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/39-timbos-apps-installing Thing is typically APPS sensor won't create a misfire. But VP44, injectors, or low fuel pressure most likely would.

That was the exact answer I was looking for if it could cause a misfire, and VP44 only has 20k on it, injectors only have 50k an EXTREMELY STIFF spring in place of the other one. Could that cause a issue, having a spring thats is extremely stiff and thicker than normal in the Airdog? Also forgot to mention my truck doesnt smoke white which is usually a tell tale sign of either your injectors or burning coolant, well I checked for combustion gases in the radiator and there was none, and I dont have a power loss or anything else really just a miss.

[Mopar1973Man]

You might consider pulling the injectors and pop testing them.