Engine/Transmission (1994 - 1998) Bucking and Black smoke

[RWorth]

My friend has a `96 4x4 4:10's 5 speed stock minus cat. While pulling a load and going to higher rpm's, around 2200 rpm's before shifting, the truck starts to surge and buck and belching black smoke. I have seen post talking about the throttle springs but no one said they were seeing black smoke. Could the smoke problem be caused by fuel being added with lower boost and weak throttle springs causing a surge. I would think the black smoke is due to low boost pressure. Other than this the truck runs fine and as far as I know the truck does not do this when it is not pulling a load.



Any help would be appreciated.

 

[redram]

My friend has a `96 4x4 4:10's 5 speed stock minus cat. While pulling a load and going to higher rpm's, around 2200 rpm's before shifting, the truck starts to surge and buck and belching black smoke. I have seen post talking about the throttle springs but no one said they were seeing black smoke. Could the smoke problem be caused by fuel being added with lower boost and weak throttle springs causing a surge. I would think the black smoke is due to low boost pressure. Other than this the truck runs fine and as far as I know the truck does not do this when it is not pulling a load.



Any help would be appreciated.

There is a TSB at the dealer for a 'Bucking Truck' for the 95 - 97 5 speeds that replace the throttle springs. It may be that the injector pump throttle is bouncing causing the irradict fuel volume - black smoke, etc.

If this has not been done, first place to start.

Also, check the ujoints and center carrier bearing on the drive shaft. Under load, you could be having a binding.