After recent trans install i now have intermittent hesitant shifts and what feels like shudder on the highway. I took to shop and they found nothing wrong with tranny. I then thought about MAF sensor so i unplugged it and now it has a bit of hard shift due to maf being unplugged but hesitation and shudder are gone. i cleaned it and still old problems when i put back together. I had an extra one here from olds bravada of same year so i cleaned it and installed and same thing. When unplugged again problem gone. Is it possible for IAT to be bad and cause this?

 

Is the SES light on? If so, what DTC's are in the memory file and pending file?

After the engine sits for 8 to 10 hours without being run, (first thing in the am), before starting the engine, connect a scan tool. Turn the ignition to the RUN position, (do not start) and check IAT & ECT data, and ambient temperature. All three should be within 2 or 3 degrees of each other. Post your results.

EDIT:
Also check fuel pressure and leakdown. How many miles since the last tune up using AC Delco spark plugs, wires, cap & rotor?

 

Unfortunately scanner dead but all new tune up last week to eliminate that possibility and i tried running without IAT today and it sure didn't like that and upon unplugging maf ran fine again. plugged back in maf after 20 miles and some slight shudder but normal shift. Is there a way to test maf with voltage meter for a certain voltage?since all problems go away by simply unplugging maf but yet replacement didn't fix it I am curious if both r bad.

Believe tune up was all autolite

No ses light either

 

Disconnecting the IAT tells the PCM that the engine is injesting -40F air. That's not usually the case in the lower 48 States! (Thank God.) The MAF sensor is commonly measured in hertz, not voltage. Autolite wires are great, they spec out better than AC Delco at half the price! These things are really fussy when it comes to plugs, cap & rotor though. Might be worth checking with the auto parts store to upgrade to AC Delco. There are several threads here on the forum regarding problems with brand new parts other than AC Delco. Nothing about fuel pressure and leakdown... have you checked it? Low fuel pressure could cause what you're experiencing and not set a DTC in memory, (or turn the SES light on).