bogging out on 1990 Ford Ranger

starts out fine until i reach about 2500 rpms then boggs out for a second or two then catches itself and is fine until i shift and hit about the same rpms?

3 answers
Do you have a Check Engine Light on? It may be an over active EGR valve. The code will help in determining what the problem is.
Same problem here mechanic said fuel pressure was'nt enough so I changed fuel pump, did'nt make a difference,maybe Map sensor is dirty.This has been ongoing for about 2 yrs now really could use suggestions?
Yes sad to say sme saga here.1988 ranger 2.9l v6-has low vacuum at idle speeds,runs rough,very low power while climbing hills and tach jumps around like mad.I have replaced fuel pump,filter,distributor,full tune-up w/fuel injector service,tested back presure in exhast by dropping the catalyidic converters-----still runs the same help!!!