Slight miss or sputter at cold start

[Ski-me]

Truck really has been running very well for several years. Recently, at the initial cold start, I've developed some sort of slight sputter or hesitation. I notice it mainly when it's cold, but have noticed when warm, I may get just a slight miss. The main sign is if I start it cold, and within a short time, put it in reverse, I've had it almost stall (and a few time the motor actually stalled).

I decided it doesn't hurt to install some Tune up parts, because it's been awhile.

New AC Plugs, Cap, Rotor, Fuel Filter, PCV valve, Air Cleaner. Ran some Chevron Techron injector cleaner and premium fuel. Not much of a change.

Put in some new AC Delco plug wires, no change.

About 4 years ago I did replace the internals of the TBI unit, and new injectors.

It does idle pretty good normally, just a very slight sputter on occasion. Just bugs me more than anything.

89' TBI 350.