Troubleshooting

Tiny
ANNABELLE
  • MEMBER
  • 1997 FORD F-250
  • V8
  • 2WD
  • AUTOMATIC
  • 135,000 MILES
My truck (Ford F250 heavy duty) starts shaking and loosing power after driving it for about an hour on the highway. The transmission has trouble shifting gears when this starts happening. This is new and started over the last 300 miles on a long drive. There is a small oil leak most people thing is a seal. I had the transmission fluid changed 500 miles ago. The check engine light is on--it was read as a couple of random misfires on cylinders 1 and 2. When this happens the gas mpg drops by about 50%.
Thursday, November 25th, 2010 AT 6:47 PM

1 Reply

Tiny
ERNEST CLARK
  • MECHANIC
  • 1,730 POSTS
Your tranny is probably fine. There's two kinds of misfires: Ignition and lean (fuel).

Always start at ignition by looking at plugs, wires, coils, ignition module, sensors, in that order.

If ignition checks out, move to fuel: pump pressure, fuel filter, pressure regulator, vacuum lines and fittings, injectors, sensors in that order.
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Thursday, November 25th, 2010 AT 7:19 PM

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