I have a 98 expy and i notice a miss around 1500rpm's it seems to run fine if you give it more gas. But when your driving like around 35 it feels like it has an intermenant jerk. I changed fuel filter, spark plugs and tranny filter and fluid. Cleaned maf and throttle body. No check engine light coming on. Ford said the coil packs where fine and couldn't find anything. Must not of looked too hard. Anyone else have the same problem with theres and what was it. Could a 02 sensor be going out? Any ideas at what to check would be helpful!!

 

I would see if it done it with the OD shutoff. Sounds like maybe it is having problems with that.

tom

 

Have you checked for trouble codes to find out what cylinder or cylinders are misfiring. My truck was misfiring after I did a plug and injector change, however I was able to scan for codes myself and found the exact plug that was causing the problem. It just needed to be tightened more. Took a whole 1 minute to fix and the misfire disappeared. If you have a misfire a trouble code should be present and it should tell you exactly where the problem is.

 

Does it do it while in Park, or just when driving.

I've gota set of bad tires that causes my truck to 'bounce' down the road between 40 and 45 MPH. It feels like the whole truck is shaking.