I'm desperate for help on this. My Grand Am, as of 6 weeks ago, hesitates at speeds at or above 45 mph. it is sporadic and not constant even when it does happen..somtimes worse than other times and always worse the faster I go. RPM's jump up a few hundred to nearly 1000 at speeds of 60mph or faster during the hesitation. No trouble starting, no trouble accellerating..especially at low speeds..idles perfectly.
So far have had...
ignition coil fixed (it was bad)
spark plugs, etc done/replaced
fuel filter replaced
IAT (Air-Temp) Sensor replaced
Car runs better..but still has annoying problem...then the belief was torque converter.
Brouth it to trans place..highly recommended and they were great guys. Owner actually drove it home with scanner on it. 30 miles on expressway. Came up as brake switches while driving. Put meter on it back at shop..no power. Took them apart, contacts were bad. Yeay..fixed, right??
Nope!!
Still friggin does it.
Does anyone have any clue what this possibly could be??
I'm starting to be afraid it is the computer itself.
Oh..trans has been flushed and serviced through all this as well.
No codes come up at all pointing to trans or fuel pump..so you know.
Thanks in advance for helping this desperate man!