Cylinder misfire

[Novafred]

Went to start my 97 Tahoe 2dr 350 vortex with 237K miles after letting it sit for 15 minutes since last driven. Motor started to shake and wouldn’t idle right. Check codes and have a #8 cylinder misfire. Pulled the plug and it was slightly wet. Checked compression and have 180. Pulled #6 Spark plug, looked good. Checked compression and it was 160. Swapped spark plugs and wires. Started engine still misfire on #8. Replaced distributor cap and rotor, still #8 misfire. Coolant level good. Does burn oil. One quart every oil change. Replaced intake gaskets 100K miles ago. I’m leaning more towards head gasket because of the wet spark plug. Plug did not smell like fuel. Also fuel pressure at idle is 50psi.
Any suggestions? Thanks

 

[east302]

What is your fuel pressure with ignition on/engine off? After being turned off, does the pressure hold or quickly drop? Are the injectors original?

Double-check the lower intake seams for leaks along the front/back and sides between the valve covers.

For a head gasket, parts stores sell a tester to check for exhaust gases in coolant. Is there any milky residue under the oil cap? With engine cool, remove radiator cap and start it. See if a lot of bubbles come up.

Does it pass a coolant pressure test?







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