1994 2.3 Ford Ranger hesitation 2000 rpms 3,4,5th gears
Dealing with hesitation, not normally in 1st or 2nd gear, 99% of time in 3rd, 4th and 5th. Began in 4th & 5th after transmission replaced and plugs. Got worse, even after another set of plugs, wires, fuel filter and pump, converter, muffler, two coils, three complete diagnostics eventually averaging 140-180 compression #3 & 4 strongest. Scoping valves for valve bend burn or broken springs or others problems, leak down under 2-10%, fuel flow & pressure tests fine, amf sensor cleaned, but giving computer a high elevation read, fuel mix rich at 2000 rpm's with slight load. Strong in first and second gear. Starts sputtering into 3rd & 4th. Acts like it is flooding out, by creating similar load as slower speed in 1st & 2nd by riding brakes till sputtering begins, and a strong smell of unburned fuel.
Everything else checks out mechanically sound including transmission which is standard 5 speed. 145,000 miles on chassis, no leaks, no blue smoke or oil loss. Well taken care of.
One of three diagnostics showed Timing belt off or stretched by 6% and crank shaft pulley hub maybe 1% or 1/16" play.
Just did a new pulley hub and timing belt, Also put a new egr valve in.
Big question... what next?
...Computer next? Another sensor? Knock sensor? Fuel injectors even with normal fuel flow tests? What else? O2 sensor?