running terrible at times, then runs great.
thats best decribes what happening to my 1999 ford ranger 4.0 auto 4x4 truck.
it will run great after a tune up fuel filter air filter plugs and wires seemed good.
it has 150000 miles. but all of a sudden it starts losing speed 60mph slowing downto 30 to-0 mph and stalls. it starts right back up fine mostly skipping an flubbering. try and rev it up it won't rev up past 2000 rpm hold at 2000 and it may clean out and purr and rev great or it may keep flubbering.this happens idling,driveing,curising,stopping going it don't matter. cked vacurm found a leak and fixed it. this was all done to try and fix it. it did help when it runs now it runs great.but didn't fix it. thanks