Uplander hesitates and jumps going up hills - 2005 Chevrolet Uplander

run the fault codes
problem indicates a TCM problem or low transmission oil level.
as most chev transmissions are sealed with no dip stick, it may need a service by an accredited service shop or auto transmission specialist shop

A great place to start is the plugs and wires. This is a very common symptom of a tune up being needed.

nice facts, all, but no engine size options stated.
after all it's an ENGINE question.
you dont know whats there, and doing DIY> really?

one fact missing, and is key
does WOT power CATCH up
that is you move right foot fast and it bogs, we get that but what happens after the bog> ? more bog or it catches up.
if it dont catch up;, on hills, maybe fuel pressure low.
see?
at WOT there is no 02 sensors. nor TPS (enrich)
at WOT only you , then engine sucking air like mad the MAF at max voltage and if fuel pressure is low the car has endless bog.
see?

wot, = wide open throttle, use a hill to test, flat is useless .
max fuel is at max HP (max torque + max RPM both same time)

i own an 08 wrangler, 3.8L stick.
i just sold my 02,. with 2.4L I4, it was a bogging engine day one out of factory its a gut less I4. (only tubo can fix it)
2.4 or 4.0 L.
ive own all of them 4 and 6cyl.

have you looked up the codes? sounds like a clogged filter or bad fuel pump. Either way, have the check engine light looked at.

change fuel filter

mass air flow sensor its in the air intake pipe

you might have the problem from the fuel filter... or not enough fuel pressure from the fuel pump.

You may have a blown head gasket, do a compression test.

Have the fuel pressure checked the fuel pressure regulator valve may be acting up, it should be at 30 psi or greater at idle. It may also be a Oxygen sensor causing the car to run lean on acceleration, if it has never been changed have the primary or bank 1 O2 sensor changed out they should be done every 60,000 - 80,000 miles. If all this has been done there may be a vacuum leak somewher in the system and by the way all vacuum hoses should have been checked during the tune up.

shift your gear to the left one tap to go into drive 1 when climbing steep hills and it keeps you from hesitating .it works for me i have a 2009 caliber automatic and i climb alot of kentucky hills ,mine only hesitates on the really steep hills after i slow down and take off again but when i shift to d1 its fine