i was getting ready to bring the 97 Impreza sport to my mother and it suddenly has a hesitation problem at lo idle. I would ble the throttle position sensor but I replaced it 2 years ago. I checked for vacuum leaks. Are there any other known problems with low idle hesitation. I get nothing until I press the accelerator down halfway and then the power launches in. .... How I love the old days of carbs and distributors. Any tips are appreciated. Thanks

Does it feel shaky like a misfire? How old are the plugs?

 

Knock sensor can cause hesitation and is a common failure. If the housing is cracked replace it.

thanks for the reply...found it....hose under mass airflow had a crack.....now to get her detailed and deliver to mom tomorrow.....I will miss this car a lot   but mom needs a dependable car i will still get to drive it once in a while when i go down to az to maintain it