folks - searched here but can't find answer.
1999 ranger, 3.0, 6 cyl. flex fuel, 2wd, extend cab xlt

problem:

rough idle, engine misses/stutters primarily at cruising speed. ok through acceleration but when throttle is feathered to cruise, begins to bang and miss. i can correct by lifting, feathering or pedaling accelerator, which takes it back to smooth for a bit. then back to banging it goes.

from forum threads, i have replaced:
ignition coil pack
plug wires
MAF sensor
IAC valve
ECT sensor
DPFE
B1 O2 sensor
cleaned throttle body

truck has been in shop twice for the issue with wrenchers doing some of the work and me doing some.

i'm am still fighting working the problem and can't seem to find a solution.

most confounding is that issue is intermittent. though present more often than not, i can experience what i just did which is fire it up and drive errands around town on lunch with absolutely no problem. I can also feel it drop off from smooth to stutter or surge from stutter to smooth on the highway.

AND...check engine light has not been thrown; no abnormal noises coming from engine (other than rough). does sometimes smell like running rich.

stymied. any help will be appreciated.


stymied.

thanks