91 toyota pick up..stumbles on acceleration

[skerfer22]

i have i 91 toyota pickup 22R 4wd 250,000 miles with regular mainteince. When cold runs fine but when it warms up it wants to stumble during acceleration through the gears... Checked fuel pump pressure good. changed fuel filter. Done tune up and adjusted valves. Idles fine. After it stumbles a little bit it seems to clear up until the next gear then the same thing happens.

 

[CJF]

Why for you post this in Chat?

That said, sounds like spark plug wires to me; did you change them as part of the tune up?

Curtis

 

[sisukid1975]

O2 sensor?

Fred

 

[cruzizzle]

Second the O2, mainly because its a hot/cold issue and the difference between open and closed loop modes.