Haven't had my Series III out for about six weeks (I know, I know, shame on me for not driving it!), and now it's back-firing, not real loud, but back-fires after shifting, and sounds like its coming from the right side of the muffler pipes. Any quick ideas so I don't have to tear everything down?

I've got my annual emissions test coming up and this may present a real problem.

1972 Series III V-12 E-type Roadster, Silver, navy blue interior.

Submitted by nrife@tombrown.com on Mon, 08/23/2004 - 13:34

Didn't have much time on Friday to respond, but I started by checking the plug wires to make sure they were all tight and found 1A a bit loose. I also filled the tank with Stabill and topped off the gas tank. No back-firing yet.

I suspect I may have had some condensation in the tank. Our summer weather is usually so dry, condensation is never a problem. We've been unusually wet this summer; much needed moisture after years of drought. The gates on our fences are so puffed up we can't open them and neither can we open the door to our backyard Tuff Shed! We're not used to this!

The real culprit is lack of use. Since my husband bought a Harley two years ago, and parks it in between my E-type and my Land Rover, I don't drive it much because I can't get into it when the Harley is in the garage!

Thanks for all the advice!

1972 Series III V-12 E-type Roadster, Silver, navy blue interior.

Submitted by nrife@tombrown.com on Fri, 08/20/2004 - 18:06

Thanks for all the tips. Yes, I hate to admit it but the gas is at least a few months old. I live in Colorado and our climate is normally so dry, condensation isn't much a problem, but this summer has been unusually rainy.

1972 Series III V-12 E-type Roadster, Silver, navy blue interior.

Submitted by therays@flash.net on Fri, 08/20/2004 - 16:43

Patrick's right -- if nothing else has changed on the car and depending on the age of the fuel, you could have bad gas. With steel gas tanks, water condensation gets into the fuel and can contaminate the gas. Water sinks to the bottom of the tank and gets suctioned into the fuel delivery line. Of course, water won't burn in the combustion chamber, creating a backfire effect.

If the gas is more than two or three months old, you may need to drain the tank and put in fresh fuel. Short of that, you might try a "dry gas" additive to remove some of the water.

Also, have you checked the fuel filter? Sometimes, that can get clogged and "starve" the engine, creating a backfire condition.

V-12s need a lot of good, clean gasoline.

Glenn Ray
'66 E-Type OTS

Submitted by mcload@ev1.net on Wed, 08/18/2004 - 19:28

I don't think a loose wire would cause a backfire; I would tend to believe a timing problem....but what do I know of V-12's! Are you mis-labeling a back-fire for a miss? Those are two different problems with different causes.

The new "oxygenated" gasolines can go bad in a matter of months. If you don't drive your car on a regular basis (and refresh the gas in the tank), you should add Stabill to your gas.

Patrick McLoad
1966 E-Type, Right-hand Drive Roadster

Submitted by nrife@tombrown.com on Wed, 08/18/2004 - 15:19

1972 Series III V-12 E-type Roadster, Silver, navy blue interior.

I replaced all the plugs and the plug wires last year. Maybe one's come loose. I didn't think about the D-cap being loose, though.

Any ideas on when old gas become old?

Submitted by mcload@ev1.net on Wed, 08/18/2004 - 13:59

I'd check plugs first for fouling, and to see which bank may be showing the problems. You might also check to see if the choke is disengaging fully. Also, see if your distributor is loose and happened to turn abit.
How old is the gas?
Just throwing out some possibilities.

Patrick McLoad
1966 E-Type, Right-hand Drive Roadster