Stumbles climbing hills

[doogie]

I have a 1982 Silverado 2wd 6.2 (Stock) with overdrive automatic with 95K miles. When I climb hills it stumbles then clears itself then stumbles and so on. It feels like its loading up then it cleans itself out. It feels like a miss but I don't know alot about diesels. Smoke output is black and heavy while climbing hills. Any ideas?

[DmaxMaverick]

Does the power fall off, or cut out (like a miss)?

If it just falls off, probably a fuel supply problem. Change filters and check lift pump status. If there is any fuel dripping from, or leaking around, the pump, it's due for replacement. Does it continue to blow black smoke, even when the power is down?

If it is cutting out, it should be an electrical problem. Worn out motor/tranny mounts can cause grounds or connectors to break. The torque and/or incline (G force) could be causing it.

Does the engine have EGR? The 8th digit of the VIN will be a "C" if it does, else a "J" if not. A failing EGR vacuum valve can cause power loss at high demands if it tries to pull open the EGR under load, and will blow lots of smoke.

Does the fuel tank level seem to effect it at all?

[doogie]

Thanks, I will check the things you mentioned. It does smoke badly when the power is dropping off. It does have EGR.