94 jeep wrangler

1994 JEEP WRANGLER
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SCOTTY000
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i recently bought this 94 wrangler it has an automatic trans.and i think a 2.4 ltr. 4 cyl. eng. with over 100,000 mi. on second eng. is what i was told, it runs great at an idle but when i get up around 40-50mph. it starts cutting out backfiring etc. i can shut it off and turn it back on and it quits for a little while but then does the same thing , it has good fuel press. i checked it , any ideas ?
Feb 7, 2007 at 5:28 PM
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2CARPRO JACK
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Try an ignition coil
Feb 7, 2007 at 7:00 PM
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SCOTTY000
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thanks i will try that this weekend
Feb 8, 2007 at 6:38 AM
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SCOTTY000
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tried a new coil this weekend , that didnt do the trick, put new plug wires on that seemed to take the backfire away, but now when i rev the motor up a little and hold it steady it surges up and down, could this be the fuel pressure regulator or maybe a vacuum leak ? help please. thanks, scotty
Feb 12, 2007 at 12:06 PM
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2CARPRO JACK
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could be either one. Also test fuel pressure to be sure it is within spec
Feb 12, 2007 at 4:10 PM
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SCOTTY000
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what should the fuel pressure be,pressure regulator seems to be working fine, but i still get an up and down surge while holding the throttle at steady speed ?
Feb 22, 2007 at 12:44 PM
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2CARPRO JACK
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I think your Jeep is gonna have to go on a scanner to watch the sensor outputs. What you are describing could be many different things
Feb 22, 2007 at 1:52 PM
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SCOTTY000
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my fuel pressue is 24-25 psi book says its supposed to be 31, could the 6 psi difference make it act like this ? i also did the test it called for in the manual and the pressure never changed. it does not surge up and down any more with steady pressure on the throttle, i dont know why it quit all i did was put a new exhaust system on. the engine idles great but when i get it on the road right before it shifts it stalls and backfires through the throttle body. anymore suggestions before i put it on the computer ?
Feb 28, 2007 at 1:20 PM
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SCOTTY000
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TURNS OUT IT WAS A WEAK FUEL PUMP CAUSING MY PROBLEM,SO I FIXED IT,DROVE IT TO GALVESTON AND IT WORKED FINE GOING BUT ON THE WAY BACK IT STARTED A NEW PROBLEM. IT WOULD DIE ON ME WHILE GOING DOWN THE ROAD,I COULD TURN IT OFF,CRANK IT UP AGAIN GO A FEW THOUSAND FEET AND IT WOULD DO IT AGAIN AS SOON AS I HIT THE GAS PEDAL,WHEN ITS COLD IT WILL CRANK UP AND RUN FINE UNTIL I HIT THE GAS PEDAL THEN IT DIES AGAIN. ANY SUGGESTIONS ?
Mar 22, 2007 at 11:40 AM