i have a 1995 GMC jimmy 4.3 vortec that had a blown head gasket i tour it all apart and replaced all gaskets and had heads milled. its all back together now and will turn over fine but wont fire. i have fuel and spark but it just dont want to fire, any suggestions? thanks

 

Everything connected properly? Is it timed correctly?

What does it have for a distributor? Vertical wire terminals means the older ignition system while horizontal terminals means the newer EDI system.

For the older ignition system, timing is set to 0 (zero) degrees with the timing wire disconnected. The timing wire is a brown or brown w/ black tracer wire on the inside of the firewall, to the right of the transmission tunnel, just below the upper lip of the carpet.

The newer EDI system is computer controlled and requires a bi-directional scan tool to set the CMP retard. This system won't fire the spark without a functioning CKP sensor. The distributor install is different for the EDI setup as well, requiring two marks on the balancer be lined up, not just one. The requirements are covered in the Tech Article (DIY) section. An index of the articles in that section can be found in my signature below.

 

everything but the plug on top of the intake is pluged up, not sure wher the wire went for it. its the older distributor the book said to turn it tar wards the number one cylinder when its TDC but after turning it to the #1 cylinder and adjusting it to a few different places it still doesnt act like it wants to fire

 

Are you sure you have the #1 cylinder at TDC on the compression stroke? If not, the distributor will be 180 degrees out and it won't run.

 

it was before i put the heads back on, that was the first place i turned the distributor to

 

I would pull the #1 plug and find TDC #1 on compression and then check the rotor alignment.

 

ill check it again and see if it will get it running, appreciate the help