Greetings,
Ive had my '01 Tacoma 5spd 3.4 201K for nearly a year now and love it. I'm getting 19-20mpg and it idles smooth and runs great at speed. It is not showing any engine codes and it looks ot have bene taken care of by prev owner.
However, it will usually misfire when accelerating right after an up-shift. Above 2400rpm or so...no problem. Just intermittent and split second stutters/hiccups. The wider I have the throttle open the more pronounced.
This combination suggests to me fuel delivery as a bad plug I dont think would be more across the board random. Fuel punk or injectors perhaps ? Or a timing issue where not enough advance affects ignition during these circumstances?
Just fishing for ideas and suggestions.

 

Having a similar issue in my 98 4runner, while driving normal speeds above 50 mph, when truck shifts into O/D at around 1800 rpm I get a minor stutter/stumble usually one to three in combination and then if I accelerate and the truck goes out of O/D the miss disappears during the down shift. It has returned but is not consistently missing. I have tried Sea Foam in gas tank along with a treatment of Techron additive in a subsequent fillup. Not sure what is causing it. Still getting around 19-21 mpg (207,000+)