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mid to high RPM studdering and backfire

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Old 08-22-2012, 11:44 PM
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Angry mid to high RPM studdering and backfire

I recently just bought a 1987 jeep Cherokee with the 4.0 l inline 6 with a manual transmission and 158000. When I drive around town and highway I shift just when it starts to studder and spatter I shift up into higher gear and it stops. If I don't shift the studdering gets worse and turns into bucking then backfires. As the problem starts it feels like it just needs to clean itself out but then it just gets worse and then backfires and acts like its starving for fuel. When I go downhill it does not start the problem until I apply any type of throttle and its over a certain RPM which I cant tell exactly because I have no TAC. The idle seems fine but sometimes it fluxuates when sitting.

I am going start with plugs, wires, cap, and air filter. Does anyone have any other suggestions like maybe the cat converter or any other solutions.

Need Help.

Thanks
Old 08-22-2012, 11:49 PM
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Whats the fuel pressure? If the spark goes away distributor bushings could be toast.
Old 08-22-2012, 11:52 PM
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just recently I had a similar problem with my XJ. and a CPS code was diagnosed. I finally pulled the dist cap and could shake the dist. rotor almost 1/8 of a in
I replaced the whole dist and no more problem
Good luck
Old 08-23-2012, 07:00 AM
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Vacuum.
Old 08-23-2012, 07:02 AM
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Okay, so you just got this Jeep.

Put new plugs, wires, cap and rotor on it. Clean the throttle body.

Have you checked your trans, transfer case, and diff lube levels and condition?

Basic maintenance needs to be performed/confirmed first.
Old 08-23-2012, 08:45 AM
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Thanks for the advice. Ya im going to do all the basic maintenance to it and a full tune up when I get a day off. I just was seeing people with similar problems and getting complicated and expensive solution. I'll start cheap and easy and work my way through it.
Old 08-23-2012, 08:47 AM
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Originally Posted by bseats
Thanks for the advice. Ya im going to do all the basic maintenance to it and a full tune up when I get a day off. I just was seeing people with similar problems and getting complicated and expensive solution. I'll start cheap and easy and work my way through it.
That's the way to do it.
Want some cheap and easy things to do to prevent future problems?
They address known issues and fill the bill as preventative maintenance just as much as what you're gonna do anyway.
Old 08-28-2012, 10:15 AM
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Well an update, I got the jeep fixed. Found out the previous owner had already done a full a tune up under the hood. So I replaced the fuel filter and no change so I replaced my fuel pump since I knew it was a fuel issue. Got a replacement from autozone and the jeep runs great. The new fuel pump is definitely pushing some pressure.
$800 jeep and $125 for fuel pump and filter equals a great deal especially since it has brand new tires.

Thanks for the help.

Bseats
Old 08-28-2012, 12:10 PM
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Now what about the other maintenance stuff that requires some attention?
Old 08-29-2012, 07:12 AM
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Ya I have gotten there yet. I was planning on doing it on one of my nights off this week, but got called to a fire so it will have to sit till I get back.
Old 08-29-2012, 07:16 AM
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Brake is not the same as break......
But Broke is
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