Help please

How long since you had the fuel filter changed?

 

I would say that ,before you throw any more money at the problem, take to a dealer and have it hooked up. There's just too many sensors on an engine now that you can't diagnose yourself

 

With the engine at idle, press and hold the engine shut down override switch. This will cause the yellow check engine, and red stop engine lights to flash. These are the engine fault codes. I'll try to explain how to read them. They are all two digit codes. A series of flashes followed by a pause, then another set of flashes. For example three quick flashes, pause, four quick flashes is faultcode 34. There will be a longer pause then the next faultcode will flash. It will cycle every code in memory so write them down. The yellow check engine light displays the inactive, stored in memory codes. The red stop engine light displays the active codes. On a ddecIII and Ddec IV flash code 34 is turbo boost sensor voltage input low. So if my truck was flashing an active 34 I would know I either have a bad turbo boost sensor, or a bad wire going to our from the sensor. Flash codes are an invaluable for diagnosing an engine problem. I hope this helps.

if you bought the truck new you should have the reference pamphlet, if you don't you can probably Google it, I suggest getting one from Detroit. Makes sure you get the right one for your engine

 

If you hook up to reader for your ECM it will be able to see if signal is being received from throttle postion sensor. You may have bad wire from sensor to ECM. That would be the first thing I would do. When you press the accelerator is there any change in RPM?

 

sounds like you have an ecm problem or a vehicle harness issue

 

Alfa, did you get the flash codes? Both the inactive, and the active?