Model A running Flat

tagroff

tagroff

Member
Okay here is the problem. She runs pretty good until you put the advance all the way down then lets say after 3/4 the way she just flattens out and seems to lose power. I have retimed and they are fairly new modern points any other hints to try. I know someone on here has had to of had this problem...Thanks before hand for all the help
 
Follow what Jim said!
Stop advancing when you hear ANY pinging or when the engine no longer picks up speed or power, which ever comes FIRST!
 
Maybr I didnt explain it well enough..It starts running flat at about 40 mph . I think it should run better then that the motor was rebuilt about a yr ago and has few miles on it so should still be fresh. It doesnt have a different head on it compeltely stock.
 
Check your point setting (0.020) then check your timing. With the spark level all the way up, withdraw the timing pin and turn it around. Remove the distributor body and cap. Turn on the ignition switch, put transmission in neutral and set the emergency brake. Insert the timing pin in backwards with pressure and turn the engine over with the crank. As soon as the the pin sets into the timing gear recess a spark should occur between the breaker points. If not adjust timing.
 
I'm reading your posts to mean that your engine loses power after reaching 40 mph with the spark advance all the way down (fully advanced). If so....I'd try it with the spark advance set about half way between fully retarded and fully advanced. Or where the engine smooths out at high idle. I think the guys above are telling you to not advance the spark as much as you are describing.
 
OK, now it sounds like you are runnng out of gas. Check for good gas flow at the carb. Must have a steady stream for several seconds into a quart jar. If that's OK, then check the carb for problems.

Always do the easy checks first. Just to make sure you have a good spark, hold the coil wire at least a 1/4" from a head nut and crank the engine with the key on. You should have a good blue spark.
 
I agree with Tom about gas. One common cause of your issue is the repop gas line between the sediment bulb and the carb. They are notorious for having too much line sticking out of the brass ferrule at the carb end. (Also at the bulb end, but it doesn't matter there.) Cut the line back to about 1/8" beyond the ferrule. If it's too long it pushes into the filter screen restricting the flow considerably.

This doesn't have anything to do with advance, though. In your two posts you described two different problems. If it runs good at 40 or higher until you pull the advance all the way down, it's probably a timing issue. If you can't get it beyond 40 no matter where the advance is,, it's probably a gas flow issue.

Joe
 
Sorry I havent replied earlier. But some of what you guys say makes sense. I did change the fuel line inside the cab and also the one to the carb. As I stated before it just seems to flatten out and also sputters and coughs alot when first started. Here is a picture of her..1928 Roadster Pickup
 

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My 2 cents :) Sounds like a fuel starve issue to me, whether a flow from the tank issue, plugged jet, or GAV that won't open. On mine I need to crack the GAV open about 1/4 turn while warming up or it's as cold blooded as can be and hiccups.. I also need to crack the GAV open fr higher speed runs where I am > 3/4 throttle
 
I rebuilt my zenith, placed it on the car and it started and idled fine. Backed out the driveway and down the road I went. It accelerated to forty and then no more, I played with the mixture and timing on the road, still no faster than forty. I was going on a club run so just kept going. Started with a full tank, and fifty miles later, had to fill the tank, it only had half a gallon left in it. After the run, got home, took the carb off, went to the work bench, found the GAV seat, and fitted it to where it should be. Now the car goes faster than forty and uses a lot less fuel.
What I'm suggesting here is, it could be fuel.
 
Thanks for all the replies I will take the carb off and get it checked out ..You guys have been very helpful ,,,,,Thanks Again
 
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