Carb / Valve Issue?

mpalilonis

mpalilonis

Member
Having a major engine issue with the A and wanted to check with you guys to see what I'm perhaps missing.

So a month ago I ran the A to the store, ran great, came back turn the gas valve off and ran it out of gas. Yesterday, I went to fire it up and she ran really really rough, engine sounded like it was galloping and wanted to stall, backfired a couple times and had no power when I went to pull down the driveway. So I checked the voltage from the battery all the way to the points, all read 6.3v. Checked the plugs, little black sooty, so I cleaned them up and put back in. Took the carb off and opened it up to see if I could spot a problem. Nothing. While open I put all new jets in and new filter. Tried to fire it back up and it was really a struggle to get it to fire up, once it did it still galloped and ran rough, then it just died and I couldn't get it started no matter what I tried.

Soooo I'm looking for a little help from the experts and anyone that might have encountered this issue before.

Thanks Guys!!!
 
Do the easy checks first. Hold the coil wire 1/4" from a head nut and crank the engine with the key on to check for a good blue spark.

If you have good spark, look for a carb problem, or gas flow problem.

I never like to change parts unless I know they need to be changed. Hope you saved all the old jets.
 
you may have pulled some dirt or something up into the carb when you ran it out of gas and you missed it when you cleaned out the carb. or it could be a bad condenser. I would try a compression check just to make sure the block is up to pressure and you are not having a problem there. I think I would put a known good carb on just to make sure that yours is good or bad.
 
Check the fuel flow TO the carb. I have had 2 in the last few months with similar symptoms. Pulled the fuel line loose at the carb; slow fuel flow. Turned the fuel line up above feel level. The blew into line, felt the line to free up. Let gas flow into sediment bowel a couple times. Cleaned out the bowl. Put line back on and my friend finished his 50 mile drive. Happened again on our coupe, same symptom, same fix, same result. Tanks need to be flushed and a pencil filter installed. I think large chunks are getting caught in the fuel valve and restricting flow. Good luck.
 
Thanks guys, I forgot to mention I put a new valve in under the dash and put a new pencil filter in as well. Then tried staring as I mentioned above... Still problem. I also pulled the fuel line from the bowl, hooked a brass adapter up to a plastic flex line to check flow, all was good there. I have a compression gauge, but not the 7/8" adapter, going to have to get it. I will try the other suggestions in the morning and see what I find.
 
If it was running fine, then all of a sudden it wasn't I would suspect the float valve in the carburetor is sticking shut. When ever I rebuild a carburetor one of the things I do is check the action of the float valve on a test stand I built. I mount only the top casting to the stand with a glass container mounted below. The stand has a fuel reservoir above. When I pour fuel into it, it flows into the glass and fills it and causes the float to rise. I can tell by looking in the glass where the float shuts the valve off (the fuel level should be a nominal 5\8" down from the bottom surface of the casting). I can then monitor it for a period of time to see if it holds this level and does not creep up. It will also tell me if the valve is sticking shut.

My experience has been that the after market gross-ball valves are notorious for sticking shut. It may have something to do with the gas sold here in California. I have had good luck with the viton tip float valves sold by Bratton's.

Tom Endy
 
A good rule of thumb is not to change things until you know what is wrong.
Repro jets are not a plus. Most are not that good. When you start changing things you might end up with more than one problem. That will make harder to figure out.
First check for gas flow at carb, and spark at the plugs. Should have a solid stream of gas, and a good blue spark.
 
Well... I gave up on it! It was kicking my butt, so I sent it over to a friend to diagnose it. So two things.... One, the previous owner put a modern distributor plate in it and its grounding out, so off that comes and back to stock it goes. I was getting a poor spark and it was causing the plugs to foul. Last, the carb is F'd up so the new parts I put on it didn't help, nuts! Lessons of the day... Don't make too many changes to quick. Start with the simple checks first... and ask a friend for help so your whole house doesn't smell like gasoline, making for a pissed wife...hahaha.
 
I had nothing but trouble trying to run the so called modern points. The wireless lower plate for use with MODERN points is even worse. On the other hand,One month is long enough time for ethanol adultrated gas to go bad. Fuel additives didn't help the adultrated fuel for me. Thank goodness we finally got a station in our town that sells unleaded gas with no ethanol added.
 
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