BUCKING Rodeo

My 91 Rodeo (Manual 4WD) is bucking like a bronco as slow speeds. At idle it mostly lopes almost to teh point of stalling and then reves up adn later drops. At highways speeds it does okay, but always seems to want more gas. then when shifting at lower speeds, but at crising rpms it begins to buck or feels like it loses power unless I go above or below that rpm range. I've had most every sensor replaced or checked out ($1600 worth). My mechanic has checked out the Throttle Position Sensor and says it's within spec. . Any ideas?

Well.. I'm glad it starts with a "B". What engine? if it's the GM 3.1L, I'd check the MAP sensor (manifold absolute pressure). It's mounted on the air cleaner housing with a vac line & wire or two going into it.

G/luck
Joel

Thanks for the quidk reply. It is the 3.1LGM engine. The mechanic has changed out the MAP sensor, O2 sensor, typical tune up stuff like wires, plugs, also computer,. Like I said, about $1600 worth.

FWIW - try changing gas stations if you use the same one all of the time; also, have you had your Cat Convertor checked out?

Also check for any kind of intake air leak; fuel filter, fuel pump.

This is a tough one being that we don't know if this is fuel or spark related. Has the ignition module/coils been looked into?

Joel