Why does my truck smoke alot when cold?

[BushWakr - RIP]

Normally the smoke on cold starts is due to timing being too retarded. There is a solenoid that is responsible for advancing the timing to help reduce this condition until the engine starts to warm up and burn the fuel more efficiently on it's own.

There are times when even that compensating solenoid is still not sufficient to deal with the excess smoke on cold starts. Normall this can be dealt with by advancing the injection pump timing over the stock settings and that, in conjunction with the timing advance solenoid (KSB solenoid) will cure most of that problem.



Bob.

 

[dpuckett]

Little more detail.....

Dieseld are a compresion engine, which means they run best when fully warmed up. But, for the first few minutes after a coold start, it ISN'T warmed up, and combustion temperatures are very low. This can cause bluish or white'ish smoke, not totally unlike a camp fire when first started- lots of smoke but little heat. When combustion warms the engine up a little, the smoke should dissipate. Advancing the timing a few degrees when cold (via the KSB or some other cold advance) will increase in-cylinder COMBUSTION temps (different from EGT), thus cutting the blue and white smoke until the engine builds enough heat of its own. If you have a little blue smoke when cold, dont panic; you don't necessarily need a rebuild like in a gasser.



A diesel engine will not build much heat at idle. You can let it idle all day and not reach 140 deg. It is best to start it up, let the oil get circulating well, and go easy on the load/ pulling for a few miles until the temp gauge starts to move. Once you get to about 140, or halfway up to normal operating range, you can drive normally.



Daniel