Backfiring issue and 4x4 issue with my 86'

[jmartinez1228]

So I have 2 issues that just recently started with my jeep. Its a 4cyl 2.5l by the way. The first one is almost everytime I shut the truck off it backfires like a [bleep]. I havent done anything to this truck so I don't know why it would do it.

 

Secondly today was the first time I used the 4x4 (had snow today) and while driving down the road I started to hear a loud rubbing noise coming from the front end which sounded like the differential or the axel. Once I took the truck off 4x4high the noise went away. I'm really hoping its not the differential thats bad because i have no cash to buy another one.

 

Any help would be appreciated. Thanks

 

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[Edited by Eagle to remove language not acceptable on this board]

[jmartinez1228]

anybody?

[Geonovast]

We're you using 4x4 on dry pavement?

 

Your backfiring is probably a bad O2 sensor or spark plugs, or a hole in your exhaust very close to the motor.

[jmartinez1228]

No I was using the 4x4 in the snow, some of the roads were very slushy while others still didnt get plowed.

I actually purchased new spark plugs, cap and rotor so I will try to replace them this weekend. Anybody have any tips on getting the spark plug that closest to the front of the car? The ac unit is right next to it and I realy didnt want to pull it all out. What should the plugs be gapped to?

[jmderyke]

Most usual cause for back fires are air leaks so check everything intake, exhaust, vacuum lines,

egr valve.

Have a work manual for your truck? If so look at trouble shooting guide and it will lead you to some proper tests. If not......mmmmm you can look up a pdf manual on the internet and download it for free. I downloaded one for my comanche it covers xjs and mjs. It is missing quite a few things but it will help you for sure.

I don't have ac on my 2.5 so i don't have that problem. It should be fairly easy to get too, maybe a universal joint on just before the socket or a wobble extension??? Or just put the socket on the plug and put a wrench on the end of the socket? sorry idk

[bmaley79]

use a spark plug socket and then a swival then an extension and should come out. I did mine last week.

[jmartinez1228]

Thanks Ill try that with the plugs. Apparently from looking around the gap should be .035? Can someone verify that?

 

Any ideas about the 4x4?

[Pete M]

hard to say with the front end. Have you tried wiggling the front driveshaft around to check for bad U-joints?

[Eagle]

anybody?

Ya know -- it's Wednesday, which is a work day. You posted at 9 something in the morning, when most people are at work, and you get antsy and bump your own thread when nobody has responded by mid-afternoon?

 

Why don't you give people a chance to at least get home from work and have supper?

 

Have you ever used the 4WD before? The front is driven by a chain, so 4WD is always noisier than 2WD. The noise you hear may be normal. If you've used 4WD before and this is different or louder, please post a better description.

 

As to the front spark plug, I believe you have to pull the a/c compressor. In the '84 4-banger XJ I had, that was the only way.