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Discussion Starter · #1 ·
My truck is putting out gray smoke, but not always. Sometimes it is good and black, then next time I start it up it is gray. Maybe some less power. Now is were it gets crazy. Just put in laser cut DV's from Scheid. Retourqued the studs, they were good. The valves were good also. Smokes more now, but gray and runs alot slower. I was getting 42#'s of boost now 32 and it doesn't rap up like it used to. I am going to replace the lift pump, reblead the lines, and clean the fuel heater. Any other ideas. It has been gray smokin for a while, but not always and the timing is dead on. What usually causes smoke like this? Air in line, lack of fuel, water in cylinder, or hopefully nothing to expensive. :$:
 

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Bump along..

What you describe sounds like retarded timing or a compression issue on the surface.

Does the smoke smell very strongly of fuel? White/grey is normally caused by not having enough heat to combust. Could be retarded timing; the fuel is injected too late to build enough heat before TDC to combust cleanly. Could be loss of compression preventing enough heat from building during the compression stroke to begin combustion before TDC.

Do you have an infrared temp gun to see if all your cylinders are running at the same temp?

Do you have test strips to see if you are getting combustion gases in the coolant?

Blowby normal?

Valves seating properly?
 

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Discussion Starter · #3 ·
ok, put the new lift pump on seems better but can not get #6 to bleed and when I crack it, it doesn't change engine sound. seems to have air at injector and at pump when cracking. Tomorrow will check dv's and injector. Ran out of time and light today. "true shade tree mechanic"
 
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