Bad white smoke and popping.

[Towriggity]

I've got a 93 w350 cc dually, under normal circumstances it drives ok, although a little slow and underpowered for my liking. However, if it is in neutral and give it any throttle it begins to white smoke and terribly and pop and backfire. Under load it will throw only black smoke and never miss a beat, what could this be? The truck has a piston lift pump, bhaf, straight exhaust, and pump cranked to collar, auto trans if it matters, thanks in advance for any help,

Jake

 

[peobryant]

Try a 1/8" timing bump and see where that gets you.

 

[powerchoke-eatr]

Could possibly be a broke injector nozzle too. U need to crank it and make sure all 6 exhaust ports are the same temp after running a few mins....

 

[98.5dodge]

sounds like a injector problem may have one sticking open for to long.

 

[oldestof11]

Put a fuel pressure gauge on it. If it has the stock LP, then you need to upgrade a bit to either a new stock LP or a low pressure piston LP.

The low pressure piston LP helps top end and fuels everything. Lack of fuel does the same and can account for less power.

If it reads 3psi at idle after the filter, either you need a filter or a LP....

 

[travisbennett7]

oldestof11 is right put a fuel pressure gauge on it. Sounds like either an injector is sticking or air is coming into the lines somehow.