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Old 11-29-2021, 05:15 PM   #1
fordmerc7
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Default wrong rotor position

Distributor rotor points between the contact points in the distributor body when at TDC as determined by timing gear indent. At this time the points are open. What is wrong?
Background: car ran slightly less than perfect when head gasket leaked. New head gasket installed. Now engine runs roughly if at all. Rotating the rotor closes the points when the rotor points to the body contacts. I did not knowingly alter the position of the lower distributor shaft.

What did I do wrong? Suggestions for next step would be appreciated.
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Old 11-29-2021, 05:38 PM   #2
nkaminar
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Default Re: wrong rotor position

If the distributor is timed correctly the rotor will point to the correct pole for the number 1 cylinder. Did you put in another rotor? Maybe it is defective. Check to see if the rotor is seating correctly.

Re do the timing. Set the timing with the spark lever all the way up. The points should just be opening. Check with an ohm meter or light bulb. The more exact you are the better the results.

Some members have reported bad timing results when the front cover that has the timing pin is a Model B on a Model A engine. Check to see if the piston is really at top dead center when the timing pin is in the dimple on the cam gear. You can do this by peeking in the spark plug hole or sometimes by just the feel when turning the crankshaft back and forth by hand.

Also check to see that the pin on the bottom of the distributor is seated in the hole in the head.

Your timing is off.
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Last edited by nkaminar; 11-29-2021 at 06:17 PM.
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Old 11-29-2021, 05:57 PM   #3
Bob from Northport
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Default Re: wrong rotor position

Thus is where the rotor should point at TDC. Courtesy of Marco T.
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Last edited by Bob from Northport; 01-24-2022 at 09:39 PM.
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Old 11-29-2021, 07:21 PM   #4
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Default Re: wrong rotor position

it could be nothing more than play in the distributor shaft & gears. Be sure that when you set the timing and tighten the cam screw, that you are turning everything clockwise. With all of the play out of the distributor shaft, your rotor should look like the image in #3 from Bob, and your points should just be opening with the timing fully retarded
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Old 11-29-2021, 08:09 PM   #5
fordmerc7
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Default Re: wrong rotor position

I have attempted re-timing the distributor with the spark lever all the way up. I have used a test light in the process. The distributor is the one that has worked flawlessly in the past. The distributor fits onto the head properly.
My problem is that at TDC, my distributor will not look like the helpful image provided by Bob from Newport.
The problem remains that after attempting re-timing, with clockwise and counter clockwise considerations for play, I cannot get the rotor to be where it should be and the points open because the rotor is 45 degrees away from where it should be as demonstrated by Bob’s image.
Please add some alternative problems that I may have caused during gasket replacement or at some other time.
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Old 11-29-2021, 08:12 PM   #6
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Default Re: wrong rotor position

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fordmerc7,
I think what you are saying is that your rotor pickup is sitting "between" the contact point on the distributor body. If that is the case, you have the distributor cam not set correctly. In other words, you have your timing off by a lot.
As others have said, try re-timing with the pin in place. You want to position the
distributor cam so that it is just ready to open the points. That is done by unscrewing the screw in the middle of the cam. Make sure that your spark advance is either all of the way up, or even a click down. Make sure that you set the points so that you have at least .018 gap to .021.
After all of the above, when you replace your rotor, it should look like the picture that Bob provided in thread #3.
Let us know what you find.

Tom L.
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Old 11-29-2021, 08:32 PM   #7
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Default Re: wrong rotor position

Get to TDC...pull distributor and align the rotor to the proper position, should fit into the slotted oil shaft rod, make sure it is fully seated, now re-do the timing.
Something is off from when you pulled the dizzy during the head gasket, have you looked at the slotted oil shaft rod? It should only fit one way
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Old 11-29-2021, 10:52 PM   #8
Bob from Northport
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Default Re: wrong rotor position

Pull the #1 plug and make sure you are TDC with the piston all the way up. If the distributor/rotor does not line up where I showed you, it is possible the timing gear is worn and it has jumped time. You can use a mirror at an angle to look into the timing pin hole and see if the small indention in the timing gear is there-lined up
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Old 11-30-2021, 01:07 AM   #9
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Default Re: wrong rotor position

It'd be helpful to see a top-down picture of the distributor with the engine at TDC and you having just re-timed it according to whatever procedure you normally use. One picture with the rotor on and one with the rotor off.
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Old 11-30-2021, 09:17 AM   #10
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Default Re: wrong rotor position

Post where you live, maybe someone close to you can give a helping hand!
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Old 11-30-2021, 09:20 AM   #11
nkaminar
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Default Re: wrong rotor position

How did it run when you re timed it?
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Old 11-30-2021, 10:59 AM   #12
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Default Re: wrong rotor position

I'm trying to post images per alexiskai - that might help, but I haven't figured out how to get my images into the post yet. I'm working on it
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Old 11-30-2021, 11:19 AM   #13
Bob C
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Default Re: wrong rotor position

Quote:
Originally Posted by fordmerc7 View Post
Distributor rotor points between the contact points in the distributor body when at TDC as determined by timing gear indent. At this time the points are open. What is wrong?
Background: car ran slightly less than perfect when head gasket leaked. New head gasket installed. Now engine runs roughly if at all. Rotating the rotor closes the points when the rotor points to the body contacts. I did not knowingly alter the position of the lower distributor shaft.

What did I do wrong? Suggestions for next step would be appreciated.

When the rotor is in the position in Marco's picture the points should just be starting to open. You need to turn the rotor until the points are almost closed. The spark occurs
as the points open.
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Old 11-30-2021, 12:58 PM   #14
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Default Re: wrong rotor position

Quote:
Originally Posted by fordmerc7 View Post
I'm trying to post images per alexiskai - that might help, but I haven't figured out how to get my images into the post yet. I'm working on it
PM me if you need help
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Old 11-30-2021, 01:25 PM   #15
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Default Re: wrong rotor position

Do you understand to set timing, you have to loosen the screw and move the cam once the pin lines up with the divet in the timing gear?
If the screw is not holding the cam in place that is a different matter.
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Last edited by redmodelt; 11-30-2021 at 01:35 PM.
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Old 11-30-2021, 01:52 PM   #16
nkaminar
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Default Re: wrong rotor position

1. Assure that the piston is at the top when the pin is in the dimple.

2. Time correctly. Many others have said how to do this. There are also many Youtube videos that can explain it to you. Some are better than others. There are also good books to show you how.

3. Post where you live. I was able to help a fellow Barn member that was in driving distance to me. I checked out his entire ignition system and timed his engine in about 40 minutes after he had tried unsuccessfully for several weeks.
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A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
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Old 11-30-2021, 02:04 PM   #17
fordmerc7
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Default Re: wrong rotor position

Hopefully images attached which show rotor and rotor off under circumstances of points open and closed
I do believe that I know how to set timing and have done it repeatedly.The cam is held consistently in place with screw tightened.
I have had some help from a friend with 7 Model A’s however we got interrupted and have been unable to resume.
Attached Images
File Type: jpg points open 1c.jpg (39.8 KB, 67 views)
File Type: jpg points open 2c.jpg (36.2 KB, 64 views)
File Type: jpg points closed 1c.jpg (42.8 KB, 67 views)
File Type: jpg points closed 2c.jpg (38.1 KB, 66 views)
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Old 11-30-2021, 02:15 PM   #18
fordmerc7
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Default Re: wrong rotor position

Hopefully images attached which show rotor and rotor off under circumstances of points open and closed
I do believe that I know how to set timing and have done it repeatedly.The cam is held consistently in place with screw tightened.
I have had some help from a friend with 7 Model A’s however we got interrupted and have been unable to resume
Attached Images
File Type: jpg points open 1c.jpg (39.8 KB, 14 views)
File Type: jpg points open 2c.jpg (36.2 KB, 19 views)
File Type: jpg points closed 1c.jpg (42.8 KB, 20 views)
File Type: jpg points closed 2c.jpg (38.1 KB, 19 views)
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Old 11-30-2021, 02:35 PM   #19
alexiskai
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Default Re: wrong rotor position

OK, the Nu-Rex upper plate is pretty easy to time visually with a B distributor cam. At TDC, looking down from the top, the upper edge of the cam slot should align with the lower edge of the rubbing block as illustrated with red lines in the attached photo. This will position the points just barely closed and they'll open in the next instant as the rotor turns CCW.

This advice applies only to the Nu-Rex upper plate, the stock plate looks different.
Attached Images
File Type: jpg Screen Shot 2021-11-30 at 2.30.20 PM.jpg (16.7 KB, 33 views)
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Old 11-30-2021, 02:36 PM   #20
john charlton
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Default Re: wrong rotor position

My suspicion is that the cam is not tight on the shaft . With the distributer seated and secure see if you can rotate the rotor by hand . It should not rotate only slack in the drive shaft/camshaft connection . If you can move it the plain washer under the cam could be missing (this is NOT a lock washer) or the maybe repro cam screw is too long and bottomed out. Remove the cam and check the underside it should have clearly defined grooves which help it to lock to the distributor shaft . Take out all the spark plugs so you can rotate the engine easily and use the gizmo on the timing cover to find TDC no 1 . Use Robs picture and rotate the rotor so it is EXACTLY the same as the pic tighten the cam screw use the " New Rex" cam wrench so the cam does not move when you tighten . Put the gizmo and the plugs back and it will run like a champ . The Rob picture is the key you cant go wrong (trust me !!!) As long as the points widest open on any lobe adjust to 18 thou or credit card or thereabouts .When you tighten the screw take out any anticlockwise lash gently .

John in Suffolk County England ..

Last edited by john charlton; 11-30-2021 at 02:42 PM.
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