Here's a problem that I have with my 94 GM 6.5 TB diesel and I hope someone can help.
When I push on the accerator petal from rest position aprox. 1/4 - 3/8 of an inch and hold it there. I noticed a slight jump in rpm. This increase in rmp is more noticable when I'm going down a hill at 80k/h. or when the engine is under low loads. This increase in rpm is also noticed when the cruise control is on. What happens here, when I'm cruising let say at 80k/h and I start to go down a hill. The truck will speed up and slow in a jerking fashion as the cruise control is trying to control the speed. This jerking motion can be simulated with the accerator petal and always at the same petal position.
I can give an example here from 0-10, 0 being the accerator petal at rest and 10 is accerator petal at full throttle. The throttle will seem to go from 0 to 2 and skip 1. This is where the jerking motion is. As I go pass 2 everything is fine.
I have no 'accelerator petal' fault light and have no faults on the 'check engine light' The bulbs in these socket check out OK during start up.
I changed the accerator petal and the pmd anyway and still have the same proble. I'm starting to suspect the fuel solenoid valve might be the problem as it is allowing too much fuel in when the throttle position is at 1.
The truck starts up fine and idles great. once I'm past that throttle position the truck runs perfectly.
Any suggestions
Thanks
When I push on the accerator petal from rest position aprox. 1/4 - 3/8 of an inch and hold it there. I noticed a slight jump in rpm. This increase in rmp is more noticable when I'm going down a hill at 80k/h. or when the engine is under low loads. This increase in rpm is also noticed when the cruise control is on. What happens here, when I'm cruising let say at 80k/h and I start to go down a hill. The truck will speed up and slow in a jerking fashion as the cruise control is trying to control the speed. This jerking motion can be simulated with the accerator petal and always at the same petal position.
I can give an example here from 0-10, 0 being the accerator petal at rest and 10 is accerator petal at full throttle. The throttle will seem to go from 0 to 2 and skip 1. This is where the jerking motion is. As I go pass 2 everything is fine.
I have no 'accelerator petal' fault light and have no faults on the 'check engine light' The bulbs in these socket check out OK during start up.
I changed the accerator petal and the pmd anyway and still have the same proble. I'm starting to suspect the fuel solenoid valve might be the problem as it is allowing too much fuel in when the throttle position is at 1.
The truck starts up fine and idles great. once I'm past that throttle position the truck runs perfectly.
Any suggestions
Thanks