Back Fire

I havent driven the jeep much this winter, but took it out for a spin today. Started up fine and idled fine after warming up. I drove down the road and when accelerating I get a lot of sputtering and back firing. When I got home, I removed and pluged the vacuum advance line, checked the timing and it was at 5*. Any idea what might be causing this? It all sounds like the timing is off, even didnt have much power on acceleration. Checked it again and I'm still getting 5*!

 

Thanks, I put five gallons of fresh fuel in, but I didnt try the dry gas. I'll give it a shot in the morning.

 

I had similar issues when I had a bad spring on my points. While you haven't changed anything it may be worth checking.

 

I'll take a look at them. I changed them last summer and they haven't been great. I ordered the pertronix yesterday and it should be here mid next week. From what I've read on this site they work well. I was wondering if something could be wrong with the distributor since it only seams to happen while accelerating under load. Any thoughts?

 

Let me know what you think of the pertonix. I was thinking of going that route. if you have a dauntless let me know the part number

 

I called pertronix yesterday and they gave me part #1165 for the ignitor and 40511 for the coil which I quess can be used without the ballast resistor. I should have it next weeek, I'll let you know .

 

Maybe, Its been very cold here and it may have gotten some condensation in there. I was thinking also the last time I used it I left the key on and maybe it burned the points or condenser.

 

I would think a little more about the problem before trying a bunch of things.

Backfire is caused by fuel in the exhaust igniting. If you have backfire now that you did not have now, that means that there's either more fuel or more air in the exhaust now. If the engine misfires, the unburnt fuel will be pumped into the exhaust where it could burn. A new exhaust leak could admit more air into the exhaust, and the usual fuel in the exhaust is now igniting. A choke stuck closed will richen the mixture and more unburnt fuel will enter the exhaust.

 

I thought I give you guys an update:

Yesterday I installed a spare set of points & condensor, set the dwell to 30* and set the timing to 5*BTDC. With the vacuum connected the timing does advance when the engine accelerates.

The backfire did go away! The engine starts up nicely, idles nicely but does not have the usuall amount of power when accerlerating.

I also received my Remanufactured Carb. and now I'm wondering if the lack of power issue could be caused by it?

Pertronix and a new coil should arrive mid week, I'm going to give that a try also.

Are there any adjustments or items to look for on the Carb that would contribute to lack of power?