sstout351

I replaced the timing chain on my 95 mustang gt when i crank the engine with number one plug sucks air in through the spark plug hole. I checked the timing marks on the cam and crank they look dead on. please help

mgmuscari

Well it'll do that on the combustion stroke... what's really important here is to make sure that the cam and dizzy are properly aligned. 180 deg out between the crank and cam should make no physical difference as near as I can figure. Both rotations of the crankshaft are identical...

sstout351

there is no compression coming out of the piston at all. on both rotations on the crank it is sucking air in. no exhale if you will.

mgmuscari

that doesn't really make any sense. you've got your rockers installed, right?

what you're looking for is the compression stroke. it's not an exhale. when both valves are closed, it's compressing, then combusting. then the exhaust valve opens for the next upstroke, which is the exhaust stroke, and the intake valve opens near the top of the for the intake stroke... rinse & repeat.

if both strokes are "sucking" on your finger on the downstroke, it means the valves are closed. this can only happen on the compression/combustion cycle, or if you don't have your rockers on. if you aren't feeling any compression, then you've either got bad rings one of your valves is sitting off its seat for some reason, or you're some angle *other* than 180 out. i could see weird stuff like this happening if the cam was 90 out or something. you'd probably be having piston to valve clearance issues then, too.