3406c cat motor running weird.

Injector

 

This^^^^^

 

Could be a few things. Have you drove it under load? Could be air in system ie- bad o-ring, cracked fuel lines from tank. Or weak check valve or transfer pump. Water or gelling if cold temps plugging up filter. Or a bad headgasket that isnt toltaly failed yet and your burning off coolant at startup. Last thing, bad o-ring on an injector or bad injector.

 

Is this a peec engine or mechanical?

 

On the left side of engine do you see a rod going from the pump to your foot pedal in cab?

A peec engine will have a ecm on the left side with a bunch of wires.

Can you give us the engine serial number? It will start with 3zj or 4 ck.

 

I would have thought any peec engines left would have been converted over to mechanical by now.

peec was a pos in most peoples opinion. Converted it was a great running mechanical.

If its cold outside, sounds like a normal start up for an old mechanical engine. Otherwise what @superhauler says