Mystery Problem Changed Symptons.....

'91 Wrangler with a 4.0

Had some trouble about two weeks ago with cutting out as I was driving down the road. Changed the Crank Position Sensor, and it worked fine for a couple days, then cut out once more, waited 10 seconds then it started up again and ran excellent for another week, no more cutting out...Then, some other problems started. The engine now has drastically reduced power. It won't go over 60 on the higway, and at highway speeds it sounds kind of like one of those import cars with an aftermarket exhaust pipe. The mechainic can't figure out whats wrong. Please help!!! Could it be some of the connections? electric? Not once has the check engine light come on, the only code the mechanic can get from the computer is one that has something to do with the air conditioning.

Please help me! Phil

Reply to
Mariner15
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On a 91 I would immediately suspect and remove and clean the wire mesh body ground cable from the engine head to the firewall for all your symptoms.

A bad connection between the battery and the block can cause it too.

You can look for it with a multimeter.

With the engine running and the headlights and even the heater fan on, put the volt meter on the battery posts and take a base reading. Then leave one on the positive post and go with the other to the negative cable clamp, then to the engine block, then to the alternator case, then to the body of the Jeep. When you find the/a voltage change, that section will have the bad connection.

You can do the same starting with the negative on it's post and walk the positive cable connections to the power distribution box and starter relay. You go to the clamps, then the bolt or post it is bolted onto to see if that connection changes the voltage. Event the slightest voltage drop is bad news and that connection will need a clean.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

If the substrate in the catalytic converter breaks up and obstructs the exhaust, it can at first be intermittent and cause your exact symptoms. Be sure to rule that out.

Spdloader

Reply to
Spdloader

Reply to
L.W.(Bill) Hughes III

Change the ignition module. I had similar problems with my 89 YJ.

Reply to
Dano

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