Troubleshooting my FE

[patrickt]

What's the exact model number for your carb?

[CompFi]

Originally Posted by patrickt

What's the exact model number for your carb?

80805-1
Date code: 1177

My deciphering from the Holley website, the above info for my carb translates to “950CFM ULTRA XP CARBURETOR”
https://www.holley.com/products/fuel...rts/0-80805HBX

Date code translates to 117th day of 2017, or 27 April 2017

[sunman]

MSD problem
Backfiring thru the carb is an ignition issue

[patrickt]

That's a pretty fancy carb. But a Holley is still a Holley and cracking open your secondaries is just the old school way to do it when you don't have an integrated idle bypass valve, which you have. 98% of all Holley drivability problems are the primaries not being set properly on the transition slot, the idle mixtures being off, the floats being off and the change in under hood temperatures that makes the air thinner in a car like your Cobra.

But, we could be completely wrong and you really have a bad spark problem. Maybe the MSD box, the coil, the pickup, who knows. The absolutely correct way to approach your problem would be to swap a known-to-be-wonderful Holley 750 Vac Secondary from someone's car at the local Cobra club on to your car and see if all of sudden the problems were gone. Is that a possibility in your case? It doesn't even have to be a Cobra club, an old Ford or Mustang club would do just fine.

[CompFi]

Originally Posted by patrickt

...The absolutely correct way to approach your problem would be to swap a known-to-be-wonderful Holley 750 Vac Secondary from someone's car at the local Cobra club on to your car and see if all of sudden the problems were gone. Is that a possibility in your case? It doesn't even have to be a Cobra club, an old Ford or Mustang club would do just fine.

The closest member of the New England Cobra Club I know is almost 200 miles away. Unfortunately...

I went to my local Cars & Coffee and asked around about local shops etc. And everyone pointed me back to the same shop that I tried last year. And they didnt seem to have much carb expertise. Unfortunately.

I have a buddy that knows how to use his timing light. When he is available, we can check the timing.

In the meantime, I will follow the Holley tuning instructions for the rebuilt carb.