1993 Jeep Cherokee Wagon Runs Bad When Fuel Tank Full

Reader Question
Engine runs rough when fuel tanks is less than 1/4 full

Hey there

COULD be something funny with the electric fuel pump inside the tank…I would definitely start with checking the fuel pump pressure at the engine with a fuel pressure gauge you can rent from your local auto parts store.

You might try banging on the bottom of the fuel tank with your fist or rubber hammer next time the engine runs bad and see if doing that changes the running condition. If it does, you have a bad fuel pump.

Other things to look at

1. Bad spark plug wires or worn spark plugs (and is just a coincidence about the fuel level)

2. A vacuum leak under the hood somewhere. With the engine running and the hood up, listen for a hissing noise and any visible rubber vacuum hose that is not connected or cut


Austin Davis

Posted in: Running Problems

2 Comments on "1993 Jeep Cherokee Wagon Runs Bad When Fuel Tank Full"

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  1. Deborah Proctor says:

    We own a 2006 Jeep grand cherokee, this question is more generic to all vehicles, but is sore spot betwwen my husband and I. He claims you should never let your fuel tank get below 1/4 full, which I could see if we lived in the boonies. He claims experts advise this, as to save unnessary wear and tear on the vehicle. Is there any truth to this?

    • admin says:

      Its a good idea to keep about half a tank of fuel in the tank. Dirt settles to the bottom of the tank where the electric fuel pump is located, so driving close to empty just sucks up that dirt. Also good to be able to leave in an emergency.

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