65 302 problem

[bnichols04]

i got my new 302 started in my 65 and set the timing on it and it is still running rough. I took out the #1 plug and it was extremely black and i took out the rest and they are clean with no carbon on the. I don't understand what would cause this Any ideas? If it helps the timing is set to 12 degreze btdc.

[Fast68back]

Have any more specifics on the engine build? What firing order are you using?

[bnichols04]

it is from a 84? mustang it is the HO model so it has the 351 firing order. dual quad setup........i can't think of anything else that would effect this??

[Rickmaan]

It sounds like an ignition miss on the #1. Check the wire with an ohm meter to make sure it's good, also sheck the plug itself, make sure the ceramic isn't cracked. Then check the dizzy. Is the rotor and cap in good shape? Are there any visible signs of crossfire or corrosion? If it's not something obvious with the ignition system I'd start looking at the gaskets around the intake, maybe one of the ports isn't completely sealed and you're getting a vacuum leak.

[bnichols04]

this might be a dumb question but how would i check for a vaccume leak around the intake i have never done that before? The plug be black from mis-firing or not firing at all if the wire is bad? Thanks for the help