My trucks engine is a 1990 5.7 liter serpentine setup TBI motor... A couple of weeks ago I started noticing that while driving at a constant speed on the highway there would be a sudden jerk (like the truck died for a millisecond) but then everything would continue like nothing happened. I kept my eye on the tachometer and noticed minimal disturbance (not even 100rpm difference when the truck "jerked"). Over the last couple of weeks the problem has been getting progressively worse. As of today the engine sputters during acceleration (like if it was carbed I would say it was flooding on acceleration) and then "backfiring" while cruising at a constant speed. -My "check engine" light has not come on -My truck has 153,000 miles on it...could this be the time for new injectors? In a possibly unrelated situation... a couple days ago as I started to drive the 4 minute drive to school I noticed a faint squeaking coming from the front end. By the time I got to school it was a LOUD squeaking...only on acceleration. I replaced the alternator and idler pulley today thinking that the bearings in one of those was probably the cause of the sound -to no avail. it doesn't do it everytime I get on the gas, but never does it while idling or "reving up" the engine while parked or while cruising at a constant speed down the road. Couple random facts: -My air cleaner is extremely dirty -I replaced my fuel filter within the last year -My exhaust has had a serious leak just after the O2 sensor for several months My current guess is: a loose motor mount or some other loose bolt in or around the engine compartment that squeaks now because it loosened up a bit.