Engine surging Part 2
 

Hey guys,

I'm back again scratching my head trying to figure out why my truck wants to surge rpms again. I have replaced the entire APPS mounting bracket and sensor, I found it on rockauto for 210 bucks. I replaced the whole thing as I replaced just the sensor a couple times but could never get it down to the right specs which i think was .595 or something and wide open was 3.6 or 3.8. So I bought the one from rock auto and it came "preset" with the factory setting it said. Well my problem is now its worked fine for about a month and now I'm having issues once I'm up to speed in top gear or just holding the throttle to maintain speed. I have ran 2 tanks of fresh fuel and injector cleaner through it and mixed it on the heavy side (I think it called for 2oz a gallon for real dirty) Is there something I'm missing that could cause the APPS to keep acting up? I had this problem on my wrangler and I just cleaned the throttle body and it cleared it right up but I don't believe diesels have throttle bodies as its controlled by the VP44 and the APPS as you press the pedal depending on how hard you stomp it it dumps fuel as needed. What else can I check? Is there a way to plug in a computer and do a scan even though I'm not getting a check engine light? Is it bad for the truck to run like this for a long period of time? Is it possible I have water in the fuel and it's not enough for the dummy light to go off on my truck? I'm on my 4 sensor in less that 5,000 miles and I don't need to just keep throwing sensors at it I need to find and solve the problem.