00 S-10 won't start

I am working on a 2000 Chevy S-10 2.2L,, that won't start. At first the guy thought the timing chain was bad, so I checked timing and timing is good, *NOTE: there was absolutely no compression in this engine, when you try to start it it sounded like the starter wasn't even engaging with the flywheel.
So I figured prolly a bad HEAD GASKET, replaced the head gasket and when I tore the head off notice a chunk was missing out of the head for the #3 cyl., so I had to replace the HEAD as well, also he had some other head work done a few months ago and all the head bolts on the outside (toward the exhaust) were all pretty loose. Well got the new head, gasket and new bolts on and finally the engine was sounding good (had some compression) but still wouldn't start. Checked comrpression and #1-150, #2-120,#3-40,#4-150, So Cyl #3 had very low compression, put some oil in the spark plug hole and compression went up to about 120 on that cylinder. So figured Piston Rings were worn. Well over the last couple weeks I've been rebuilding this engine, New Rings, Rod bearings, Main Bearings, All new gaskets and seals. Cleaned the block really good and honed out the cylinders.

Now, I got it all back together and still wont start, I am getting FUEL and SPARK and I checked compression again, Cyl#1 - 155 psi, Cyl#2 - 150 psi, Cyl#3 - 120 psi, Cyl#4 160 psi. #3 cyl is still a lil low compared to the other but it this enough to keep it from starting? I don't know exactly what the compression should be on this engine. I know on my Jeep ZJ comrpession should be between 120 -150 PSI. I also added oil to each cylinder and each cylinder goes up about 30 PSI.

Also, there is a RED 2-wire connector which I do not know where it goes. It is right next to the OIL PRESSURE SENSOR, anyone know what this connector is for?

UPDATE:

The RED-2 wire connector was for the purge solenoid for the evap system. I had it moved out of the way, laying on top of the engine and when I pulled it down I seen that connector and relized where it went.

Well I took a shot in the dark and decided to throw it all back together and it start and runs fine. I also squirted some oil into the spark plug holes and let it sit over night (friday night) maybe that loosened the rings up and let them seat correctly. Well it runs fine now.

Thanks for sharing that.