Rough when Cold
 

Hi All.

1999 Isuzu Rodeo 4cyl, 177k miles.

Recent new water pump, timing belt, radiator, thermostat.

Issue: really rough running on start-up.

It was running just fine before it started overheating. I put in new thermostat, then water pump and t-belt. Same overheating issue so towed it to the shop and they put in a new radiator. No overheating issues since, but it then started to intermittently run rough at start up, and now it seems to be running rough on start up until it is warm, then it runs fine.

Replaced PCV hose during lunch today - car runs just dandy when warm, so won't know if this solved anything till later.

Thinking maybe it is the engine coolant sensor?

No CEL.

Any thoughts?

when was the last time it had new spark plugs/wires put in?