This all started with minor miss at idle so I did some digging and found that the compression numbers are 210 210 210 and 160 so I brought the #4 to TDC and added 100 PSI of air to the cylinder and it came out of the intake so kept digging and found the intake valve spring retainer in this shape. What is going on here?

http://s737.beta.photobucket.com/use...tml?sort=3&o=1

 

See photos in this thread to compare.
https://www.s2ki.com/s2000/topic/403...tainer+failure

I suspect that retainer on the right is cracked.

 

the retainer on the right has cracked allowing it to creep up the valve. at any moment it will give and drop the valve. If I were you I would not put it back together until that retainer has been replaced.

 

Yeah retainer on the right is toast, looks to be in the very late stages of failure. Good find, consider yourself fortunate, that could literally have popped through at any moment! Retainers aren't that expensive, so won't cost the earth to get yourself back on the road again...

 

Both are broken.

Note the polished lip on the right retainer. This it from roller rocker contact.

You are going to have a bad camshaft and rocker also, 100% guaranteed.

Search retainers.

 

I see the crack in the picture now! I would have never thought that this would be a failure like this. Just today I ordered 16 retainers and valve seals and a roller. I need to find a decent spring compressor now and I hope it cures my low compression issue in that cylinder since the rocker was pushing down on the retainer and holding the valve open a bit and hoping it's not burnt.

Thanks everyone.