Ok my 91 teg is doing some strange things when I 1st start it up and begin to drive it revs really high at about 2500 rpm or so not only that but it also jerks and some times shuts off then it will drive perfectly fine for a lil bit or some times the rest of the day or it will continue the high reving and shut off pattern whats the problem and how can I fix it I just need it to pass smog and then ill start hookin this bitch up.