Hello all we have a 1999 blazer, 4.3 auto 4wd

The issue, hard starts intermittently when temps are 32 or below. sometimes it fires up fast sometimes it requires cranking wait and try again.

I have found the fuel spider does leak down, my fuel pump tested good and doesnt leak. I have the new spider and will install it this weekend.

MY Question is about the crank sensor and Cam sensor, what do they do and what part do they play in telling the motor to fire the plugs/injectors????????????

its like boom something occasionally isnt telling the motor to fire the plugs/injectors. I have tested and found the pump is delivering fuel on demand when it should. It has seem a full ignition tune up. Other than this issue the motor runs great, no ses codes, plenty of power!

 

Update, tonight i replaced the fuel spider! i took it for a drive and it seems to drive good with plenty of power! the idle seemed a bit rough!