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Starting and power / back firing issue.

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Old 03-19-2012, 05:33 PM
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Default Starting and power / back firing issue.

Now that the weather is beautiul I thought that I would try and get some issues sorted out on my 1998 Jeep Cherokee Classic 4.0 4x4.

The first issue only happens every so often. It happens when I start up my Jeep and got to take off the engine power drops down to almost nothing and if I push on the gas it just kind of sputters until I hear a pop come from the engine and then it picks back up and runs normal. After doing some reading it sounds like I am getting a backfire though the intake. Someone suggested to get a fuel pressure gauge and check out the fuel pressure to make sure its not running to lean. So off to Autozone I went to rent a gauge.

After I hooked it up the Autozone gauge and turned the key to on the pressure jumped up to 50 PSI and then it slowly bled off and stayed at 12 PSI. I did this a few times and got similar results. After that I fired the Jeep up and the needle was reading a consistent 50-51 PSI which from what I understand is normal. Any ideas where to go from here?


Second issue I am having is when I go to start the jeep the starter will be cranking and then it gets to a dead spot and makes a weird sound like. The best way to describe it would be like a flat "WHUMP". You can kind of hear it in this video when the starter breaks its normal sound. Some times it can be much louder and more pronounced. So do you guys think starter or battery? When the Autozone guy tested the battery he said that the volts were their but my battery had a dead cell. He really would not elaborate further so I am not sure if he is trying to up sell me or if it was near shift change.


Last edited by durus5995; 03-19-2012 at 07:20 PM.
Old 03-21-2012, 04:38 AM
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Does anyone have any ideas? Is more info needed?
Old 03-21-2012, 02:03 PM
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Well if u have a dead cell in your battery then u need a new one and it sounds like u should have your starter bench tested
Old 03-21-2012, 03:34 PM
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Update on the starter. Today when I started when I went to start the Jeep the starter just spun for like 20-30 seconds before it started rolling the engine over. So I am going to get a new starter. I am still trying to chase down the intermittent engine power with backfiring issue.

The Jeep has 164,000 miles and has all the original throttle body sensors as well as the original CPS.
Old 03-21-2012, 03:41 PM
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Originally Posted by durus5995
Now that the weather is beautiul I thought that I would try and get some issues sorted out on my 1998 Jeep Cherokee Classic 4.0 4x4.

The first issue only happens every so often. It happens when I start up my Jeep and got to take off the engine power drops down to almost nothing and if I push on the gas it just kind of sputters until I hear a pop come from the engine and then it picks back up and runs normal. After doing some reading it sounds like I am getting a backfire though the intake. Someone suggested to get a fuel pressure gauge and check out the fuel pressure to make sure its not running to lean. So off to Autozone I went to rent a gauge.

After I hooked it up the Autozone gauge and turned the key to on the pressure jumped up to 50 PSI and then it slowly bled off and stayed at 12 PSI. I did this a few times and got similar results. After that I fired the Jeep up and the needle was reading a consistent 50-51 PSI which from what I understand is normal. Any ideas where to go from here?


Second issue I am having is when I go to start the jeep the starter will be cranking and then it gets to a dead spot and makes a weird sound like. The best way to describe it would be like a flat "WHUMP". You can kind of hear it in this video when the starter breaks its normal sound. Some times it can be much louder and more pronounced. So do you guys think starter or battery? When the Autozone guy tested the battery he said that the volts were their but my battery had a dead cell. He really would not elaborate further so I am not sure if he is trying to up sell me or if it was near shift change.

no video
Old 03-21-2012, 04:49 PM
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Originally Posted by durus5995
Update on the starter. Today when I started when I went to start the Jeep the starter just spun for like 20-30 seconds before it started rolling the engine over. So I am going to get a new starter. I am still trying to chase down the intermittent engine power with backfiring issue.

The Jeep has 164,000 miles and has all the original throttle body sensors as well as the original CPS.
Maybe u should take a look at all your sensors then if they have 164k
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