smokey exhaust problem

[paxton91]

I have a smoke issue that came up suddenly. I'll do my best to describe the symptoms.

The truck is cold and the right mirror is positioned down so I can see the exhaust. With the transmission in L1 (so it doesn't shift) I'll depress the throttle about a quarter to a third and hold it there. (How much throttle doesn't seem to matter. ) A light haze is evident from the exhaust, which has been normal when it is cold. BUT,... when the engine reaches the RPM's equal to the amount of throttle, a heavy, solid, dense stream of blue/gray smoke pour's out from the exhaust. Now if I do either of one of two things it will quit. Either one being more fuel or let up on the throttle. This will continue but will be less and less until the engine is warmed up. What would the first thing come to mind if this was your vehicle? The vehicle is stock with about 204,000 miles on it.

 

[paccool]

How cold is it outside? I would check the air inlet heaters for proper operation if the ambient temp is low. I believe the smoke is lighter in color than "normal" exhaust smoke when the heaters don't work right.

 

[BushWakr - RIP]

Yup, the heaters should be cycling if it's cold enough. Also the KSB should be engaging to help with the smoke, idle quality, again if cold enough. Generally you may want to check injection pump timing.



The fact that the conditions decreases and goes away when the engine is warm really leads in that direction. .



bob.

 

[phillips5]

I am lead to think that the timing needs to be bumped ahaid. At 200k. miles the gears are warn and the pump drive bushing is warn. I seen this a bunch It can get bad enough that the engine will caugh,kich,buck whenever you give it any fuel. Just a couple degrees timing advance cleans it up.

 

[paxton91]

Thankyou for your responces everyone. Really appreciate them. Gives me some directions to look into.

It will be later this week on into the weekend before I can get into it.

 

[Nordby]

If it was sudden, and if you have any loss of power or stumbling associated with it, a plugged injector can behave like this with the smoke you mention.

If something gets into the injector seat and won't let the injector reseat properly it will put out a pile of this color of smoke. One way to detect this is to see if you can high pressure bleed all injectors. An unseated injector will blow foam right back up when the piston is on its way up and the valves closed (compression stroke?)

jon