Customer with a 1991 12 valve diesel. When idling the exhaust smells like raw diesel. I was told that it could be the turbo but I think it sounds like injectors. Anyone have any ideas on what can cause this?

 

It couldn't be the turbo if your having the issue at idle because it isn't making boost at idle. It sounds more like leaky injectors or a dead cylinder.

 

I agree the turbo does nothing at idle.

 

The fuel is not burning... could bad injectors (dribbling), low compression, stuck ring(s), cold engine, etc.

The donor truck I'm using for my RC project was famous for big white/grey clouds of diesel fuel when started cold. If I plugged in the block heater for 1-2hours beforehand, it barely smoked at all.

BTW, non-intercooled injectors have 4 big spray holes vs. 6 small ones on intercooled models. Greater chance of unburnt fuel.