My A's cutting out on up's n downs

fritznbud

fritznbud

Senior Member
Today was my 1st shakedown cruise in my A, and when i climb a grade and when i go down a hill, she bogs and looses power, backfires once, then it will pick back up again. The straightaway, fairly level driving seems to be fine. I just replaced the very sooty plugs so it's running rich. It feels like i shut the key off, like i lost my 12 volts, thens fires up and backfires. All this going on at 40mph or so. Am i driving wrong or is there something up? Thanks for any suggestions.
 
do you have your spark retarded or pulled all the way down? I would think it's related to your carburetor. Take the line off the carb and see if your getting a good flow of gas! Others will be able to help also!

Justin
 
No i dont. It's all the way up. The p.o. said since it's been converted to 12V, i dont need to mess with it.
 
Besides being converted to 12V what else has been changed? Are you running an "A" distributor or has it been converted to electronic? Need to know.
Paul in CT
 
You were misinformed by the previous owner. Essentially, The Spark lever (on the left side of the steering wheel) needs to be up for starting and most of the way down or all the way down for driving. You might want to invest in some books on Model A's or arrange a visit by someone who can "show you the ropes".

The spark level being in the correct position should make a major improvement in your driving experience.
 
If it has a model A dist, then you need to have the spark retard hooked up and operable.
Starting - Lever all the way up
City driving - Lever mid way down
Hwy - Lever all the way down.
Lets start with getting the dist working properly. Did you replace the condensor too? What timing method did you use? How did you get it timed w/o the spark retard hooked up?
 
That's good to know MCHinson, no wonder it ran like crap up and down the grades, in town it ran good. I got as much info as i could before driving it. Colorado Greg, Yes , the old condenser was soldered at the end from going bad and i replaced it, the points looked great and i didn't time it. Just plugs, condenser, rotor and oil change. And the spark advance is hooked up.
 
Correction, the spark advance is Not hooked up. Rod missing, that's a good reason for my problems. Thanks for all your replies, i'll let you know how she runs when it's right.
 
fritznbud said:
Correction, the spark advance is Not hooked up. Rod missing, that's a good reason for my problems. Thanks for all your replies, i'll let you know how she runs when it's right.
Click to expand...

WARNING! The spark advance rod may have been removed for a reason. There may be a Phillips type centrifugal advance mechanism installed in the valve chamber, in place of the dizzy intermediate shaft. They were reproduced and sold by Nu-Rex not that many years ago. Using the manual advance with it will cause serious grief and possibly engine damage if you do not know it is there.
NurexAdvanceDevice.jpg

How to determine if you have one without removing the valve cover: Take off the dizzy cap and rotor, grasp the top of the shaft and cam using a shop rag or glove so you can get a good grip. Twist it in both directions very firmly. If you have one, you will hear a a slight clicking as it swings to each end of it's travel, and the shaft will rotate 15 degrees or more- much farther than just the play in the shaft coupling and cam drive gear.

If you do have one, timing it correctly may solve your problem and you will not need to use the manual advance lever. Time it using the original Phillips instructions, the Nu-Rex instructions have been known to drive people crazy and produce less than satisfactory results.

I have one in my wife's roadster, and have sold several in the last two years. P.M. me if you find that you do have one.
 
Mike, Thanks for the head's up. I dont think i have that setup. No click, but my rotor button broke in 3 places when i pulled it off. Mike's A-fordable tune up kit has a CHI-COM P.O.S. rotor in it! There's ridges in it that you have to sand off for it to fit. You gotta love the Chinese piss poor quality that we get shoved down our throats on a daily basis.
 
What a difference, i made a temporary spark advance rod from a coat hanger, took a few mile ride with my 'ol jewel, and it purrs at idle so i believe i've got it.
 
Wow! It really Sounds like an A now. I wonder why the p.o. had no spark advance rod on it? That's not something that would fly off during it's flat bed ride to my house. I got a good bit of dirt out of the bottom of the gas tank, replaced the fuel filter, fixed 2 fuel leaks and did a double oil change with 25 miles or so in between.
 
I Had problems with My Model A running bad and at that time I went to hershey (last year ) and bumped into the Nu-Rex guys ...One of them had his model A there and was demonstrating how easy it was to exactly time your Model A engine with the Nu -Rex timing kit He timed his in about 5 minutes...With the kit you get a timing scale that mounts under one of the timing gear cover bolts and you paint a small dot on your crank pulley at TDC then use your timing light my timing light I got at a swap meet it is a Sears 12 volt unit BUT it works on 6 volts ok only the light is a bit dim however back in the garage with the lights off timing with it was no problem ...I have also used a small 12 volt power cube the kind you plug right in the wall with the timing light and that works great anyway ...its all very easy doing it this way and no chance of getting it wrong ...Well Using the timing light and the kit I bought at Hershey I then timed my engine and found it WAS running at 15 degrees RETARDED when the lever was fully advanced it sure runs better timed correcly ...If you have electronic ignition the timing light method is the only way I know of to time the engine correctly ...:) B0b in Michigan
 
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