Carb backfire, Help!

[alaska'76J10]

I just upgraded to a TFI ingnition. Now, I get a constant backfire(popping) through the carb.

I've isolated it to the #8 cylinder by removing spark plugs one at a time. When #8 is disconnected, no popping.

I've checked the compression on #8 and it is good. I've made sure the sparkplug wires are not touching one another. The timimg is set correctly. The firing order has been quadruple checked.

What am I'm missing???? :confused:

[beloth]

break out a chicken and offer it up to the #8 cylinder gods.

[OldGrayGhost]

Maybe check the plug wire going into #8, swap it with another see if problem follows that wire. Look at contacts in distributor cap. check gap on # 8 plug. Compression checks so valves are sealing. Sounds like the problem has to be between where the sparks starts and where it ends.

[Don S]

..
alaska'76J10;
... Back-firing though the carburetor and dieseling or after-run can be caused by some of the following.. Fuel – air mix could be to rich or lean. Idle adjustments may set to rich.. The timing may be set with to much advance. A lot of carburetors are equipped with anti dieseling solenoids and it could be out of adjustment or disconnected.

… Sticking valves would also be a good guess. EGR systems can cause Carbon to form on the intake side of the valves and stems causing them to not operate smoothly and ‘leak’ fire from normal ignition.
… Carbon in the Cylinders is also a big promoter of dieseling, back-firing, pinging (pre-ignition) and a poor running engine.
Here’s a link to the gentle and successful way I have been keeping carbon out of my FSJ for 18 years

link> CARBON & FUEL ADDITIVES (http://groups.msn.com/JEEPTECH101/jeeptech.msnw)

Good luck and http://www.michiganjeepers.com/forums/images/graemlins/wave.gif and … CUL.. Don S..

[alaska'76J10]

Thanks all, I fixed it. It was a combo of carb mixture and bad wire. Runs good now. Thanks for all the help