1997 3.2 with low acceleration

The truck seems a little sluggish in the 15-35 mph range unless I put my foot into it. In the old days I would bump the timing up a degree or two but those book smart engineers took that option away.

Any ideas about fuel injector cleaners?

or is it possible that the transmission is slipping it has 170,000 miles and no record of it ever being serviced. I bought it at 140,000 miles from a mechanic moving out of state so I have just figured he maintained it himself.

How's the idle?

Could be any number of things, as you probably know, I have had to go through my truck and replace numerous things earlier this year due to initially sluggishness, decrease in gas mileage, complete decrease in power, followed by the truck stalling a few times, acting like it had water in the gas, then the waterpump gave out, etc.

Anyhow, I had all sparks, filters, O2's changed out, including new timing belt, truck runs/drives like a dream - feel I have a brand-new engine, when not too long ago, I thought the transmission was slipping coinciding with major engine issues coming on. Turns out, these little spark plugs and O2 sensors, especially, make a BIG BIG difference in how this engine runs.