I have a 1992 GMC Sierra 5.7 TBI, in the summer or warm weather truck runs great.Winter or cooler temp runs like a freight train, very hard to shift.engine races when push clutch in at stop signs.I let it warm for few minutes but doesnt really help,seems to calm down within 5 miles or 15 min.I replaced the heat risor from manifold to TBi didnt really help.also tried cleaner on throttle body.any help would be great.Thanks Tom

Sounds like your Engine Coolant Temp sensor is bad or possiblely a vacuum leak that happens only in the colder weather.

Use a scan tool or volt/ohm meter to see if the temp sensor is working properly. ECT sensor is located in the intake manifold near the tstat.

//2000CAYukon

Thanks for the help. Tom