95 FLD 120 Unusual Detroit 12.7L throttle issue..?

I picked up a 95 FLD 120 yesterday. Driving it home I noticed that the throttle seemed to have a dead spot somewhere in I’d say about the 10% throttle range. I thought no big deal, just change the pedal sensor and be good to go. Well got on the highway and set the cruise (bobtailing) and when I would start up a slight incline it would stutter (around that %10 load range it seemed) exactly the same as it would when I manually pushed the throttle. What’s odd is doesn’t the ECU control the throttle internally on cruise? If so the pedal sensor shouldn’t affect it at all on cruise as it’s not like some older vehicle that use an actuator to move the actual pedal for you. Anyone have any ideas? I’m stumped, I’m going to clean the sensor assembly and check it good and may pull the ecu connectors and clean them also. Doubt I’ll have any luck. I’ve read here and several other places about the ECU parameters being off but none of them stated this kind of symptom exactly. What could cause the ECU to cut out at a certain throttle position internally if it is the ECU itself?

 

I will add that it has a used DDEC IV ECU on it as well.

 

Well, that's what I thought as well. I was told that almost any of them will crank the engine and run it but to e optimized to that engine it needs to be programmed for that engine. I spoke with a lady in Dallas today at truckecm (Cant remember the exact name) and she said if I could bring it to them they would straighten it out by basically customizing all of the parameters to fit my engine vs taking it to the dealer. She would be able to customize it to fit my wants and needs vs a factory setup from the dealer. Which would include customizing the rev limiter, top speed, torque curve, hp, etc, etc. And her cost would be the same or less than a dealer charge.

 

This one is a 95 model, no ATV on it. If you are referring to the air throttle valve anyway.

 

I'll try it but this is an older 12.7L DDEC4 ECU on a DDEC3 motor.

 

According to the guy I bought it from it was plug and play. I did however notice that the fan will not engage with the switch, which should be a parameter that needs to be changed in the ecm. Fuel pressure gauge also does not work so that may be why as well.