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My wife's 79 B has been running fine up to the last couple days. We drove it 300 miles in a day 2 months ago, it purred at 65-70 all day long. She has been driving it daily with no problems. Last week, it started sputtering and missing, but she said it straightened itself out quickly and everything was back to normal. Yesterday, it started the sputtering/missing less than a mile from the house so she took it home and parked it. Last night I took it out, went about 20 miles and it did fine. This morning I tried it again and it did its sputtering/missing/backfiring trick for me. I pulled over when it started and found that it idles fine. I popped the hood, reved the engine while watching the fuel filter, it had plenty of fuel and the engine reved just fine. I moved distributor and coil wires around while it was idleing and it had no problems. I jumped in drove off and it ran fine for about a mile then started the spitting/missing again. I drove it around experimenting for about the next half hour and found that I could NOT cause the spitting/missing to occur in 1st gear. I could cause it in 2nd when I stepped hard on the gas and/or went over 3K rpm. Once the condition was happening it will occur in 3rd gear when I go over 2K rpm. Motor temps don't seem to play a part as it started when the motor was cold and was still occuring when the engine warmed up. My first thought was points but it doesn't seem to occur in 1st as high as 4K rpm. Can anyone offer some insight or direction here? Thanks.
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ran fine, now sputtering/backfiring at speed
- Thread starter kaosj
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John Moore
Luke Skywalker
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Tell us about your ignition and carb set up. Is it original? Has anything been changed? When was the last tune up. Could be lots of things. The first order of business is to make sure everything on the ignition side is up to snuff then move on to the carb.
Dozuki
Senior Member
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I'd 2nd john, chances are its the ignition. Take a look at the plugs too, they can sometimes be an indicator of what is going on. It's easy enough to replace cap/condensor/rotor/plugs/points/wires and isn't all that expensive. If it's been a while since you've done this it wouldn't be a bad idea to do it. It would also take all of those things out of the equasion. Also check the spindle of the distributor for looseness. And also check the vacuum advance hose for any signs of leaks.
Does it still have all of the emission control systems in place? This is a whole other can of worms that could be contributing to the problems.
-Doug
Does it still have all of the emission control systems in place? This is a whole other can of worms that could be contributing to the problems.
-Doug
Posting is theruputic. Your responses got me off the couch and out into the garage. While I didn't think it could be the points because I could go in 1st to 4K+ without the stumbling, I went and checked them anyway. I didn't have .01 gap when they were on the high spot of the lobe. I also noted that the nut holding the condensor clip on was loose. I got back .35mm on the point gap, tightened the condensor nut and took it for a ride. I noted that it was alot harder to startup and the manual choke played a bigger role in keeping it running than it ever did before. I half-heartedly tried to induce the problem, that is 2nd to 4K, 3rd to 3K, punch it in 2nd and 3rd - and it didn't happen. Hummmm....
As to your other questions, I have a 75 distributor on it, I have the stock Zenith-Stromburg on it with catalytic convertor and that massively weird air cleaner. The emission stuff is gone - I love Florida!
I was waiting to buy the Pertronix Ignitor, I think this may be the time. I have a ballested coil so how about some thought on the Ignitor or Ignitor II and the flamethrower 1.5 ohm and .6 ohm coils? Any recommendations? Thanks for the help and support, my wife's Brit ride is this B, mine is a Triumph Daytona 900. God save the Queen!
As to your other questions, I have a 75 distributor on it, I have the stock Zenith-Stromburg on it with catalytic convertor and that massively weird air cleaner. The emission stuff is gone - I love Florida!
I was waiting to buy the Pertronix Ignitor, I think this may be the time. I have a ballested coil so how about some thought on the Ignitor or Ignitor II and the flamethrower 1.5 ohm and .6 ohm coils? Any recommendations? Thanks for the help and support, my wife's Brit ride is this B, mine is a Triumph Daytona 900. God save the Queen!
Rats, I took it out for the real test and the symptoms are back only they happen at higher rpms now. So where as 2nd gear started sputtering at 3K rpm, 3rd gear started at 2K rpm, now 2nd goes to 4K before sputtering and 3rd to 3K before sputtering. By my calculations I could open my points to .8mm and I'd have to redline before it would start sputtering/missing in any gear. I'm afraid I'd have a hard time starting it though.
My next step is to replace the condensor as Steve suggested. Seems that the condensor, of course, has to have a wire that "T"s off through the distributor body to the coil - nothings easy is it? On the flip side I won the game of "stump all the autoparts guys in town" as that part exists only on paper around here.
My next step is to replace the condensor as Steve suggested. Seems that the condensor, of course, has to have a wire that "T"s off through the distributor body to the coil - nothings easy is it? On the flip side I won the game of "stump all the autoparts guys in town" as that part exists only on paper around here.
G
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When I had points, I used to adjust them to .016 to .018 inches. .35 MM calculates to .014 inches which I think is a little tight. .40mm to .45 mm I think would be closer to what the optimum should be. Also by just adjusting your points, the timing changed. I think if you go ahead and replace the points and condensor and adjust everything including the timing, you will be right in there with a good running engine. When you order the points and comdensor, order the cap and rotor to be on the safe side. Do all the stuff to the ignition and get that right before you touch carburation. I can't tell you enough that most carburator problems have been fixed by a good electrical tune up.
Where in Florida are you. I am East of Orlando about 15 miles.
Bob
Where in Florida are you. I am East of Orlando about 15 miles.
Bob
Dozuki
Senior Member
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Replace the wires while you're at it. (plugs too if they're a bit old). When you check your timing (dynamically) also check that your advance is working properly. Once you have your ignition sorted, make sure that everything is plumbed okay for the missing emissions. After that is sorted then you can check your carberation. Chances are it won't need adjusting, as the ignition and emissions (removal) leaks are more prone to mishap.
-D.
-D.
Things went from bad to worse yesterday. I ended at the point where there was no spark in the distributor at the points. I'm ordering a Pertronix Ignitor, flamethrower coil, picking up a new cap and rotor and starting all over again from there. Looks like the B's going to sit awhile. I'll post when all is good again. Thanks for your input.