You may have a weak cam, or your tranny is getting tired or not kicking down. How steep a hill? lol...
If a 1994 Trooper loses power going up hill and has a spark knock in the engine, the compression of the engine should be checked. It is possible that the vehicle is not running on all of its cylinders.
I have an 88 EFI truck and it loses speed (not necessarily power) going up hills because it is a manual transmission and it is geared low... and also if you are in higher altitude. Mountains ect..the electronic fuel injection may need to be redone.
Check fuel pressure.
A power loss can be from a dead or almost-dead battery. If the car loses power on a hill, it might be a fuel injector or fuel pump, if I'm not mistaken.
It loses power because going uphill is harder then going downhill therefore causing it to use more gas and then making it lose power bit by bit.
Plugged air or fuel filter? Plugged catalytic converter?
Over the Hill - 1994 is rated/received certificates of: Australia:G
Federal Hill - 1994 is rated/received certificates of: USA:R
Donald Hill died in 1994.
Tree on a Hill was created in 1994.
The Hill - newspaper - was created in 1994.
commercial truck