-0-,nada,none compression
 

Hey Guys
Fired up my ‘87 930 after it had sat for about 3 months and it has a miss. So changed plug’s and wire’s and the miss was still there. Did a compression check and all cylinders checked with 105-115# except for #2. Gauge would not move from zero on 3-4 checks. Double checked Gauge and it is good,no leaks on test hose all O rings in place. Double checked #5 and got the same reading as before (110#). So …going to do a leak down on #2 tomorrow and hopefully get some idea where to go next. Is there a possibility that a intake/exhaust valve has stuck open from sitting?
Any ideas or guidance would be greatly appreciated.
Thank You Guys!

That sucks. Leak down will give you a better idea. Anything is possible but i'd pull off the valve cover and take a look, may have a broken rocker or something.
Good luck
J

Leakdown test, as suggested, and listen for where the air is leaking. Intake, exhaust, or crankcase. That'll give you a better idea. And borescope that cylinder it with a camera if you happen to have one.

probably carbon holding exhaust open.
you can check the valve adjustment, which I would do anyway. (not that it changed while sitting).

Yes - you should be able to see the problem with the LHS valve covers off. Maybe a stuck valve. Even with a bit of carbon on the seat I would think you would register some compression. Low(er) , but some. If it is simply a valve that is not moving as you turn it over by hand (plugs out), a bit of CRC over it and a gentle tap may free it. Hard to think it is a piston problem - which really leaves you with the valves. Maybe carbon on the valve stem.
Alan