Excessive Smoke

[Tom S.]

I have a '85 GMC 2500 4X4 that smokes ALOT and smells of strong diesel fuel. I just changed the head gaskets after the truck had sat all winter, installed new glow plugs and injectors. Doesnt smoke to much at idle but gets really bad when I step on the gas. Any ideas???

[TomEichenberger]

Have you had the timing checked? I recently replaced the timing set on the ol' Burb and was amazed at how slack the chain was. Taking Jim's advice in The R&R guide, I backed the timing mark back on the injection pump(Hell, I set to the original factory marks!)Result, lots of white smoke on start up with a strong diesel smell. When I took it in to be dynamically timed , it was 6 degrees off.

[Tom S.]

I adjusted the timing and smoke would not go away, checked for air in the fuel, none. I did notice a
cut in the hose that goes from the CDR valve to the intake, hose had a good amount of oil in it. I started the motor and noticed alot of smoke in the intake, coming from the 2 hoses that are connected to the CDR. If the CDR is bad, would this cause the smoking that I am experiencing??????????

[TimK]

Tom,

Some oil in the CDR, hoses and intake are normal. This vapor from the crankcase that is being fed back into the intake manifold to cut down on the vehicle emissions. There is quite a bit of oil vapor that comes from the crankcase. As the engine gets older and the rings wear, this will get worse as the blowby will push more and more vapor out of the crankcase.

The white smoke you describe that smells like diesel sound like unburnt fuel. How smooth does the engine run? I am assuming you still have a dual exhaust system. Do you get more white smoke out of one side of the exhaust then the other?

TimK