MG sputtering and backfiring

My 63 MGB just got back from the shop, yesterday she drove great the 20 miles home. Today, when I went to start her up, the engine sputtered and backfired for about 10 minutes while it warmed up, then about 10 minutes into my morning drive, it started to lost a little power, and felt like it was sputtering again. When I went to drive home this afternoon, 15 minutes into the engine warm up, and it would not quit backfiring and sputtering. I would try to rev the engine to no avail.

what do you think is wrong? New distributer? The mechanic said mine was near shot. Any other ideas? Thanks
Josh

try looking for other threads about similar issues. there's one down just a ways from yours.

If you have a timing light, see if it is in time. If not, go get a timing light for about 10 dollars and check the timing. Your distributor may not be firing very well. Are you running points or petonix or some other electric ignition? Also, check all the wire connectors on the white circuit, especially those under the dash, as those can cause some problems (my 71 did the same thing you describe and the tach would drop to zero when it sputtered, turned out to be the 6way connector on the white wire circuit under the dash, not sure if your 63 has a 6 way, but there are wires and connectors under there to check). Also, check your plugs to make sure you don't have a lot of carbon on them. I would start with checking the timing with the timing light. Also, make sure your fuel bowl vents are clear and breathing well, mine had a problem with these too causing a popping and miss at cruising speed.

Hurst

Josh,
It could be carb needle valves overflowing.
Start it and check, if so
, tap top of pot!
Dean.

Rudy - What was your car in the shop for?

It could be that the shop changed the very thing that's causing your problem. Once or twice I've picked up a car that was worked on and discovered something like a loose plug wire. I'd first look over everything under the hood and see if something's loose or leaking or not right looking. Then, I'd take it right back to the mechanic and describe the symptoms you had when you drove it away from his shop and tell him it's his problem to put it back to normal. In a firm but friendly way, of course! If he's a good mechanic, he'll insist on doing it right. If not, you might look for another shop. Good luck.

Josh, I believe you have a good mechanic who recommended a distributor rebuild because he knew yours was problematic. He may have tried to make adjustments, but due to wear couldn't do it accurately. You and he both know that being 30 miles apart is a tough situation for both of you. It may be something as simple as a bad condenser in the distributor, but likely a rebuild is in order. I have yet to see an original 45 year old distributor that doesn't need attention! :)

I'll be happy to walk you through the replacement process. Scare up a timing light while your distributor is being rebuilt and I'll teach you how to use it. Look up my journal on this site too - there's a LOT of reading material there about tuning your ignition system!

Just a wild guess here, but since it's so easy to check, make sure your choke
is all the way off.

Just had the same problem with mine...I think Naomi had the same trouble...
Water dripped out of heater valve causing it to get into the distributor cap and cause condensation inside cap....

Might be worth a look....if it is wet...a little WD-40 will dry it up.