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...

 

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

 

How many miles on your 2000?
Did u try swapping your plug wire?

 

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.

 

ill try that too!

 

If it has the original non-TUPY 0331 head, start looking for cracks.