Intermitent backfiring

[BAsque1]

Originally Posted by ERA 778

OK. That makes sense. A loose ground wire for the MSD box would certainly cause a problem! Mounting the coil upright is the right thing to do. Make sure you drive long enough to get everything really hot under the hood. My problem would sometimes come and go with heat under the hood.
Good luck, but I think you found your problem.

I really think so I am doing one more thing and that is to change all the spark plug wires with MSD wires and see how it behaves.
Tks bud
Lou

[BAsque1]

OK guys, here is the latest update and it is a positive one. Changed the spark plug wires with MSD's noticed that one of the old wires had a sign of arching and one of the wires had unplug itself from the plug . So that said, the car is running like a charm. Tks to all of your comments and suggestions.
As they say across the pond---"Sorted"
Cheers
Lou

[Clois Harlan]

Hey Lou,

The other ground wire that you found on your coil goes to your tachometer I believe. Also, when you have some time check all your header connections to see if they are tight, just for grins. At some point these will work loose and possibly cause a backfire (usually on deceleration). Both Ricks, Tommy and others are right about backfires they are different depending on whether they are electrical or mechanical.

Hope you are have some fun in your Cobra now that you have things sorted out.

Clois

[BAsque1]

Originally Posted by Clois Harlan

Hey Lou,

The other ground wire that you found on your coil goes to your tachometer I believe. Also, when you have some time check all your header connections to see if they are tight, just for grins. At some point these will work loose and possibly cause a backfire (usually on deceleration). Both Ricks, Tommy and others are right about backfires they are different depending on whether they are electrical or mechanical.

Hope you are have some fun in your Cobra now that you have things sorted out.

Clois

Clois:
Tks I do know about this, mine were recently installed and they are tight just after recent ceramic jet coating.
Lou

[STEVE-O]

Originally Posted by Clois Harlan

Hey Lou,

The other ground wire that you found on your coil goes to your tachometer I believe. Also, when you have some time check all your header connections to see if they are tight, just for grins. At some point these will work loose and possibly cause a backfire (usually on deceleration). Both Ricks, Tommy and others are right about backfires they are different depending on whether they are electrical or mechanical.

Hope you are have some fun in your Cobra now that you have things sorted out.

Clois

When using an MSD ignition, the tach wire comes from the MSD box and not the coil. The coil should only have a black and orange wire connection from the MSD box.

[BAsque1]

Yup taken care of it Tks
Lou