HEI help please

[mesmydo]

I have a 496 BBC that I just put a new MSD high output HEI into. The engine cranks over but will not fire. I pulled a plug and it has spark and it has power to the distributor from the key. I am thinking that maybe there is a ground problem? I have aground strap from the battery to the frame and one from the frame to the motor. I used a test light to see if the dist. was grounded and as far as I can tell, it is. When I pulled that old hei out , I marked the position of the rotor and tried to get it lined back up when I dropped the new one in. If I have that position slightly off, could the plug wires be one position off and would that cause it not to fire. I tried to stay as low tech as could get with the HEI, but it still baffles me why it won't fire. Any help would be greatly appreciated.

[Jim Nilsen]

If you have spark and you are getting fuel then you have a timing problem .

A new distributor could have had the pump drive lined up a tooth off or you might be 180 degrees out too.

make sure you are on the firing stroke of the no.1 cylinder and then reinstall the distributor and turn the pumpdrive if you have to get it to line up in the correct place.

That should cover it unless you lose spark or don't have fuel.

[mesmydo]

I had the same thought ,so I pulled the #1 plug and turned it over until it popped my finger off the hole. Then I dropped it in and it was a tad off,so I turned the pump shaft a couple of degrees and it dropped right in with the rotor pointing a #1 plug. I triple checked the spark by pulling the plug and then putting it in the end of the plug wire and laid it on the exhaust and it sparks. But when I put the plug back in and try to fire it up, it just cranks and cranks with no popping,banging or anything. Could I still be 180 out or could the plugs be trashed??Thanks

[MonzaRacer]

Which plugs?

[megaladon6]

are you sure you have fuel? if you're close in timing you should get something.

[mesmydo]

The plugs that were in it were FOULED, I got some good new plugs and it fired up. I tried to clean up the old ones and I guess once they are fouled, they are pretty much done with. I am in the process of adjusting the carb and timing to get it leaned up a bit ,so the plugs won't foul so easily. Any suggestions on where I should start on timing. When it is running, I can swing the dist. quite a bit without affecting how it runs , but I know that the timing has some affect on the plugs fouling.