Backfiring

[Rob Doe]

Thanks for your post bobbader. I edited my post in #12 to indicate Zenith for those that may read thru this thread at a later time.

 

[cavalierhome]

Interesting, thanks Ill look into this. Ill play with the GAV next time Im driving. Also, my ignition cable was electrical taped into the distributor from the previous owner. Sounds like this could be a problem aswell.




I have a bit of a leak at the exhaust clamp at the bottom of the header, I removed it and muffler cemented the Sh** out of it, but still has a slight leak. I didnt think about the exhaust gases getting sucked back into the carb...



The reason for the inline filter, I cleaned the rust in the tank out myself and did the best I could but theres still small bits I can see if I look into the filler neck with a flashlight, but its much much better then before. I did put the pencil filter on the fuel valve. But the filter eventually gets dirty with rusty coloured sediment in it. No chunks of course, but theres sometimes a little bit of what looks like sand that settles in the bottom of the filter. So Im hesitant to remove the inline filter just yet.

Take the bowl filter apart. Then look up inside the top part. Is there a SECOND gasket (the small gasket at the tip of hew insert filter) accidentally left there when you changed the filter? If so it is cutting off your flow.

I had that exact same thing happen to me. I took everything apart and didn't see it. It was only when I was using compressed air to clear all passages out that the stupid thing popped out.

The car would run ok sometimes and sometimes it would backfire a lot, on and off. It took me awhile to figure that one out.

 

[ModelAMitch]

Take the bowl filter apart. Then look up inside the top part. Is there a SECOND gasket (the small gasket at the tip of hew insert filter) accidentally left there when you changed the filter? If so it is cutting off your flow.

I had that exact same thing happen to me. I took everything apart and didn't see it. It was only when I was using compressed air to clear all passages out that the stupid thing popped out.

The car would run ok sometimes and sometimes it would backfire a lot, on and off. It took me awhile to figure that one out.

Very interesting.. I’ll certainly give that a look once I get the carb off again thank you

 

[bobbader]

Well, now we know what kind of carb. I have no first hand experience with Marvel carbs, but, my advice would be to play with the choke rod adjustment ............. open or close a bit to see if things change. Assuming the carb is in good condition, this might tell you it’s just a matter of finding the sweet spot where it runs best.

Of course, there have been many other good suggestions made here and all of them are viable. Take heed .......... but remember before you start modifying (having the manifolds planed, etc) try CALMLY going through each suggestion to see if things change before you move on to the next suggestion. The Process of Elimination is always your best friend. Make a list and go through the possibilities “one by one” before you make any bold moves to try and cure 10 things at once.

Good luck.

 

[Neshkoro]

The armored cable! I had a nick in the cable between the firewall and the dash. Something that wasn't normally visible.I was having problems of the car running, not running, running. You get the idea. There were times I'd back it out of the garage to let it warm up and the it would die. All due to the nick in the cable. I found it by pulling off the dash to see if I could find anything that was causing he intermittent running. As i was fooling around with the dash, I saw a few small sparks. Long story short, I pulled all that old wiring from the dash and replaced it. The Shielded cable nick was repaired and the car now runs quite well! All those problems were because of a darn nick in that cable!

 

[ModelAMitch]

The armored cable! I had a nick in the cable between the firewall and the dash. Something that wasn't normally visible.I was having problems of the car running, not running, running. You get the idea. There were times I'd back it out of the garage to let it warm up and the it would die. All due to the nick in the cable. I found it by pulling off the dash to see if I could find anything that was causing he intermittent running. As i was fooling around with the dash, I saw a few small sparks. Long story short, I pulled all that old wiring from the dash and replaced it. The Shielded cable nick was repaired and the car now runs quite well! All those problems were because of a darn nick in that cable!

Wow.. lucky nothing worse happened! It looks like my ignition cable has seen better days but the car has no troubles starting and running, it just backfires occasionally while driving. However, the ignition cable is on my to do list for this winter.