Hesitation and backfire on acceleration

[bigaadams]

Yeah..threw me also when it started happening..very knowledgeable tech at a very well known Mopar shop in SC made the call...he was dead on..

 

[Meep-Meep]

Someone brought up mixed up plug wires and that will do it for sure. Just to be certain the firing order is: 1-8-4-3-6-5-7-2. Starting from the left front (drivers side) cylinder numbering is 1-3-5-7. 2-4-6-8 from the RT front. Check again carefully.

 

[apostle228]

You know what guys... I am an idiot. Somehow, after triple checking the wire order... TRIPLE CHECKING!... I still missed two being switched... Thats right, another case of swapped plug wires. I didnt even discover it, my neighbor did. I cheded those stinkin' wires three times, and I would have bet my left nut that they were right. Well, my neighbor who had seen me workin on it all day came by and took a look, and sure enough... Numbers 6 and 8 cylinder's wires were swapped. I dont know how I missed that three times in a row, I feel dumb now, but thats all it was.

On the bright side, despite how dumb I feel (I literally had been screwing with this for almost 12 hours), she runs like a champ! Sounds great, runs great, no issues at all!

 

[Dennis H]

Glad you have your left nut. That's critical.

 

[NJRR]

Here's proof why a second pair of eyes is a good thing. Sometimes, when you are working on something for so long, you see things the way you want them to be and don't recognize glaring errors. Hence the career of proof readers. Glad it was an "easy" fix.

You know what guys... I am an idiot. Somehow, after triple checking the wire order... TRIPLE CHECKING!... I still missed two being switched... Thats right, another case of swapped plug wires. I didnt even discover it, my neighbor did. I cheded those stinkin' wires three times, and I would have bet my left nut that they were right. Well, my neighbor who had seen me workin on it all day came by and took a look, and sure enough... Numbers 6 and 8 cylinder's wires were swapped. I dont know how I missed that three times in a row, I feel dumb now, but thats all it was.

On the bright side, despite how dumb I feel (I literally had been screwing with this for almost 12 hours), she runs like a champ! Sounds great, runs great, no issues at all!

 

[apostle228]

Glad you have your left nut. That's critical.

Truth.

Here's proof why a second pair of eyes is a good thing. Sometimes, when you are working on something for so long, you see things the way you want them to be and don't recognize glaring errors. Hence the career of proof readers. Glad it was an "easy" fix.

Double truth! Haha... I am very glad it was something easy too. At the end of the day... She's runnin right and thats what matters!

 

[khryslerkid]

Truth.



Double truth! Haha... I am very glad it was something easy too. At the end of the day... She's runnin right and thats what matters!

Good job apostle! Now have fun!

 

[J5 GTX]

another reason for backfiring through the carb under hard acceleration is a worn exhaust cam lobe..

I've been thinking about this. Here's what I thunk:
Ignition fires and the piston goes down on the power stroke.
Piston starts to come back up and the exhaust valve opens slightly.(worn cam lobe).
A bunch of the hot exhaust gas cannot get out the combustion chamber.
The intake valve opens and all that hot gas has to go somewhere. The pressure being greater in the combustion chamber, the junk runs up the intake and/or igniting the fuel/mixture.
The reason it may not happen on some cars is that the overlap is long enough to allow enough scavenge of the hot exhaust.
Plausible ?