What's wrong? Never thought I'd have to ask!

Terry NJ

Terry NJ

Well-known member
I took my 29 blind back out today. It's running very rough. Before I went, I raised the float level of my "B" carb, that made it leak! I lowered the level, That fixed the leaking but it still ran rough, intermittent miss. I was stopped for a while, so I checked the distributer. I was looking for a very loose top bearing. Nope, it was tight as new. No slop! I had set the points at .020-21 . The spark is set with a little to much advance, but I compensate with the spark lever. I'll retime it. This one bothered me somewhat though. One of the contacts in the ORIGINAL Ford dist. cap/body shows rotor contact (Only one) Beside that. nothing much! Carb. bowl is clean. Coil is orig. Ford and I found spare condensers (2) under the seat if that means anything. Can anyone shed some light?
Terry
 
Does it run rough at idle? If so, wait until evening, lift a couple of the spark plug straps so they are about 1/8 inch above the plug contacts. If its a spark issue you will see the intermittant spark at idle. Should be a hot blue consistant spark. This helps differentiate between electrical vs fuel issue.
 
If one contact point in the dist cap shows contact, the cap may be installed crooked??? There should be no direct contact there.
 
If one of your 4 contact points on the distributor body shows that the rotor has contacted it you will need to adjust the rotor contact to distributor body contact spacing so they are all correctly spaced. Bend the tip of the rotor to adjust the distance. If one or two of the gaps end up being too close while the others are correct then carefully file those contact points on the distributor body to widen out the gaps to match the others. I don't off hand remember the gap and am away from home to check my info to give you the correct gap but others will chime in I'm sure.
 
1crosscut said:
If one of your 4 contact points on the distributor body shows that the rotor has contacted it you will need to adjust the rotor contact to distributor body contact spacing so they are all correctly spaced. Bend the tip of the rotor to adjust the distance. If one or two of the gaps end up being too close while the others are correct then carefully file those contact points on the distributor body to widen out the gaps to match the others. I don't off hand remember the gap and am away from home to check my info to give you the correct gap but others will chime in I'm sure.
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0.025", I believe.

JayJay
 
Intermittent miss:

Did you clean the plugs and gap .035?

Did ya clean the point contacts with a point file or fine sandpaper, then clean off the grit with white paper folded over until no grit comes out?
Did ya oil the point pivot post with a couple drops to make sure its not sticking?

Did ya check for loose connections from the battery grounds to the safety fuse (check fuse too, it can look good but be bad) and on up to the terminal box, the ammeter, the ignition switch, down to the heavy cable ferule at the distributor, (too tight or too loose), the black wire from the bottom plate to the top?

Is the points rub block worn too much and shorting to the distributor cam?
Did ya test the ig switch for intermittent shorts by jiggling the key, left right, in out etc?

What's the ammeter doing when the cars idling? When the car misses is it flickering to negative? That would be an intermittent short in the primary circuit?

Watch for spark jumping from plugs to advance/retard linkage near plug 3.

Test distributor body for internal leakage from one plug path to another. 3 and 4 are known to crossfire.

Good luck and don't give up.
 
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You can buy a clear distributor cap from the vendors to check the sparks while the engine is running. Works best in the dark.
 
Check the screw / nut in the head that holds the distributor tight. Just saw one at the Morgantown Meet, missing and problems...suddenly one of the guys says I think I saw the distributor rock. Sure enough, the screw was loose.
 
In my Northen Illinios area I have witnessed two similar Model B Carburator issues recently.

One was cured by a good internal cleaning of the carb and all of its jets.

The other one was some gas stations are now sneaking in more ethanol into the gas then they claim. Problem on this bad gas one was cured by getting fresh non-alcohol gas and the rough running problem instantly went away.

Nothing to do with ignition at all on these two examples........
 
1crosscut said:
If one of your 4 contact points on the distributor body shows that the rotor has contacted it you will need to adjust the rotor contact to distributor body contact spacing so they are all correctly spaced. Bend the tip of the rotor to adjust the distance. If one or two of the gaps end up being too close while the others are correct then carefully file those contact points on the distributor body to widen out the gaps to match the others. I don't off hand remember the gap and am away from home to check my info to give you the correct gap but others will chime in I'm sure.
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I've cracked\broken several rotors while bending the tab...so keep that in mind and be careful when making this adjustment
 
I wish someone would make the entire distributor cap out of clear plastic.

One thinks of the modern caps.


3500-12-3500-13-2.jpg


2Q==

Joe K
 
burner31 said:
I've cracked\broken several rotors while bending the tab...so keep that in mind and be careful when making this adjustment
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That's why I never try bending one. Methinks that the rotor to distributor body gap is not all that important if everything else is good.
 
katy said:
That's why I never try bending one. Methinks that the rotor to distributor body gap is not all that important if everything else is good.
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burner31 said:
I've cracked\broken several rotors while bending the tab...so keep that in mind and be careful when making this adjustment
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A couple of weeks ago I was helping a gent via telephone / text on his A that was running a bit rough. Asked him to check the gaps and he found they were off.
He adjusted the gaps and now his car is in his own words "running better than it ever has".

I've never broken a rotor by bending the tab but I am very careful to grip it as tightly and as close to the tab as possible when bending it. If and when I do break one it is certainly not going to be the end of the world for me.
 
OK Guys! I wasn't evading replying to your many, well thought out and experienced solutions. I've had a lot of distractions in the last week. But here goes, I did change the dist. "Body" part of the cap and it runs a lot better, not perfect! But a lot better! Most of the missing (Not all) is gone, it's almost a pleasure to drive now. I had it out this AM and it reached 55-60 with no problem. won't idle properly though. This engine has a "head" on it and the timing "sweet spot" is quite a bit less advance than with the stock head. I can't give it to you in degrees, but I have to move the lever about 9/16ths ( at the quadrant) off the zero mark. I'm still hearing what I think is a ping or a knock or preignition . My ears fail me! I cannot say for sure what it is. The timing appeared correct. But it's running!
I had a guy follow me into the gas station where I buy my morning coffee, today to tell me that the brakes lights aren't working. So something else to delve into!
Terry
 
I can't give it to you in degrees, but I have to move the lever about 9/16ths ( at the quadrant) off the zero mark.
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Actually, that may be about right.

Big believer in Vince Falter over at his site www.fordgarage.com. One page in particular addresses the possibility of "overadvancing" the Model A timing.

From Vince's page. https://www.fordgarage.com/pages/bdistributoradvance.htm

The Model A ignition uses a zero crankshaft degree (TDC) initial timing point so that the engine can be easily started by hand crank, however it should never be run under load in this "retarded" position. The advance lever should always be advanced 1/3 to 1/2 travel (13 to 20 crankshaft degrees BTDC) on the steering column quadrant after starting the engine, and should generally not be run more than 3/4 advanced on the column under any normal circumstances.
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Additional compression SHOULD increase this - but your number depends on where the starting point for your advance is.

By comparison Vince relates this to the Model B centrifugal distributor - which has even less "span" than the 3/4 advance specified above. But it does begin at a different "fully retarded point." The use of hand starting on the Model B would be less likely given a higher engine compression AND the developing practice of the user.

There are several methods to get to that Model A "start" (fully retarded) point repeatedly. The timing light method is probably the most accurate.

Joe K
 
Joe K, I may be confused, but I believe that a higher compression requires less not more spark advance, as the fuel burns faster as compression increases??? I may be misreading your post.
 
You may know this, but see attachment for how the distributor should look when timed. As I recall, this picture was from Tom Wesenburg. Note his balanced rotor.
 

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