I am having a problem with my 92 tracker it do,s not run right i was driving home form work and stoped for a bit to eat and tured the key and strared fine but do,s not move fast at all im lucky if i can to 20kms it chuggs and putts the muffler sounds like it,s popping and then the rpm,s go crazy and then dies i have changed the fuel filter,alternator checked the oil, tranny and thay are fine