Misfire

[GRAT]

My # 3 cylinder is fouled and missing (misfire). All others are good and the wires are new. I get a puff of smoke on start up but only after drivinf for a while. Any suggestions on how best to repair ?


Thanks in Advance

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79 Chero WT/ TH400 /QT /360 /3" Dynomax / K&N

[bignblue]

How many miles on your rig? Do a compression test of all cylinders (the specs section of your TSM or on the IFSJA site should have proper pressure--I think it's around 120 psi) to determine if your rings are in good shape.

[GRAT]

Thanks again BIGNBLUE

If the pressure is low on one cylinder, does that mean rebuild ? I don't know how many miles. The odometer shows 00650 (approx) I have owned it since about 85000 ( 185000 ?).

Thanks,


GRAT

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79 Chero WT/ TH400 /QT /360 /3" Dynomax / K&N

[joe]

Might just be a valve guide seal leaking oil down the valve. You should do a wet and dry compression test though to see if your rings and valves are ok. For the later 360's pressure should be 120-140 lbs with a max variation of 30 lbs. keep in mind that's new engine specs. If all your cyls are pulling 115 don't worry about it but if one is only getting 85 or so and some 120 then you need to find whats wrong but the wet/dry test will tell you that.
-joe

[GRAT]

Many Thanks,

I guess I will have something to do other than eat this Thanksgiving.


GRAT

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79 Chero WT/ TH400 /QT /360 /3" Dynomax / K&N

[bignblue]

Hey GRAT--I think all you have to do is identify the offending cylinder, squirt some oil into it through the spark plug hole, turn the motor over and recheck compression--right, Joe? Once you do that, and if the compression on that cylinder comes up to match the others it indicates bad rings on that piston--right, Joe?

[joe]

<BLOCKQUOTE>quote:</font><HR>Originally posted by GRAT:
Many Thanks,

I guess I will have something to do other than eat this Thanksgiving.


GRAT

<HR></BLOCKQUOTE>

Order is important here on Thanksgiving though.
Eat/nap/eat/work on Jeep/eat/nap...
-joe http://www.ifsja.org/ubb/smile.gif

[joe]

<BLOCKQUOTE>quote:</font><HR>Originally posted by bignblue:
Hey GRAT--I think all you have to do is identify the offending cylinder, squirt some oil into it through the spark plug hole, turn the motor over and recheck compression--right, Joe? Once you do that, and if the compression on that cylinder comes up to match the others it indicates bad rings on that piston--right, Joe?<HR></BLOCKQUOTE>

Yup, if compression doesn't come up ya got a burnt/leaking/not closing valve.
-joe