I have an bad vibration at freeway speeds

1994 JEEP GRAND CHEROKEE
195,000 MILES
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MUMAH
  • MEMBER
  • 1 POST
My 94 Grand Cherokee is shaking at 55 mph, horrible gas mileage, and seems to be getting inconsistent fuel flow at low speeds. What is causing this?My engine is getting anywhere between 3-12 mpg. Strangely, it seems to only run well and drive smoothly when the "CHECK ENGINE" light comes on, but that only happens sporadically, and not often. When driving slowly at a consistent 25-35 mph the engine seems to ebb and surge with inconsistent gas flow. Then when driving between 50 and 60 mph the whole vehicle will begin to shake and shudder. Only by speeding up or slowing down does this seem to go away. Also, there doesn't seem to be any issues with acceleration. The vehicle is also putting out a lot of exhaust.
Nov 30, 2011 at 5:25 AM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
If the check engine light has been on, have the computer scanned for trouble codes. Most parts stores will do it for free.
Nov 30, 2011 at 5:27 AM
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