i had this happen a couple weeks ago. when you drive it it shakes really badly when you are accelerating. i got a cylinder 7 misfire at first so i pulled the plug and made sure that it was firing..and it was...and it really wasn't that fouled out. so i changed the fuel injector and it worked for about a day then started doing it again but now it won't throw up a cel. if i turn the overdrive off it doesn't seem to shake that much either. it shakes more around 1000-2000 rpm and not so much when you get to the high rpm's. please help asap as this is my only vehicle. o yea truck is 98 1500 4x4 5.9L.