Knocking cyl on cold start

[crecks]

On cold morning starts (-5C or colder) my truck will put out large quantities of white smoke. The smoke seems to lessen after each glow cycle the ECM gives after starting, during this same period the truck runs fairly rough. Once the smoke clears the engine smooths out, but approx 20 sec later I start hearing a very pronounced banging for about 15 sec then tappers off. I seems to me like a cyl that was not firing starts to come in. Could this be a bad injector? low comression? I've checked each glow plug (ohm and current draw) and all are good. On warmer days the banging is not there but I still get large quantities of smoke. My truck when compared to a friends 6.5 does not start anywhere near as well, some times it takes me two or three tries even in warm weather.

Thanks for any help.

Christian

[96turboSuburban]

I'm having a similar problem, poor starts in warm weather, poorer in colder weather (30 Deg. F) and more white smoke than I've ever seen before.
JUst replaced fuel filter and installed JK
remote FSD. The engine doesn't knock at all but it runs rough and doesn't have as much power.
I'm thinking of hooking back up the old FSD to see if it runs better.
Todd

[tom.mcinerney]

>>Could this be a bad injector? low comression...?

Yes.
Try 'cracking' open each injector union nut in turn [a quarter to 1/2 turn should release fuel coupling, maybe cover injector pipe/union with a cloth to prevent fuel spraying in eyes, etc]. If you loosen the connector to the noisy injector the noise will silence; you've found the bad injector...can swap with known good to confirm.
Could also compare compression here with neighboring cyls for perspective, if a diesel-rated compression gage handy. Loosen clamps on injector lines to gain flexibility.

Compulsive attention to cleanliness is helpful when dealing with fuel injection pieces; brush/spray/blow clean before opening/removal.

Injectors sometimes last indefinitely; consider renewal if more than 100K Mi.