Cyl 1 Misfire/Compression Test 2000 XJ
03-15-2016, 08:54 PM
#1
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Year: 1988
Model: Comanche (MJ)
Engine: I6 4.0L
Cyl 1 Misfire/Compression Test 2000 XJ
Been chasing a misfire since i had a massive intake leak, new manifold gasket fixed that. but now i cant figure out this misfire on cyl 1... new injector plugs coil pack, swapped plugs, injector wires, everything....tried a different tps, still nothing cant even go over 3k rpm without it bucking out and limiting me....so did a compression test tonight and cyl 2 3 4 5 6 were all 150 but cyl 1 was 110 then 60 the second time after i did 2 thru 6. Think i burnt a valve? Thanks...
03-15-2016, 09:27 PM
#2
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Year: 1999
Engine: 4.0
Put a shot glass worth of ATF in cylinder 1 and repeat the test. See if the compression goes back up. If it does. U got crappy rings. If it doesn't. Then it's probably the valves
03-17-2016, 09:48 AM
#4
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If you have access to compressed air a leak down test will give you a diffinitive answer of what has gone wrong. A cheap kit from harbor freight will do. A leak down tester is a valuable piece of equipment that will most likely be used more than once. Google how to do a leak down test, mobiles website is pretty thorough in its explanation.
03-18-2016, 01:42 PM
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Year: 1988
Model: Comanche (MJ)
Engine: I6 4.0L
If you have access to compressed air a leak down test will give you a diffinitive answer of what has gone wrong. A cheap kit from harbor freight will do. A leak down tester is a valuable piece of equipment that will most likely be used more than once. Google how to do a leak down test, mobiles website is pretty thorough in its explanation.
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