MGB & GT Forum

thank you for the help with the electronic ignition! So the previous owner apparently had the plug wires in a different order that worked (maybe what killed the pertronix).

I reset the wires 1-3-4-2 and now the car won't start. I put it at TDC and the rotor is about 5 o"clock, not 1 like i have read... the rotor fits one way only, so what is my next step?

Thank you!

A couple of things....

-Be sure you're at TDC on the compression stroke. Remember, the pointer will also indicate TDC of the exhaust stroke.
-Be sure #1 piston is actually at TDC. Harmonic balancers can slip.
-Once you've verified those things, simply put the #1 plug wire on the terminal the rotor is pointing to, and then go counterclockwise with 3, 4 & 2.

I doubt that having the spark plug wires moved from the 'normal' positions had anything to do with the demise of your Pertronix.

The distributor drive gear can be installed in many positions - only one positions the rotor (and thus the spark plug wires) in the 'normal' position. See: http://www.mgaguru.com/mgtech/ignition/ig103.htm
(do make sure the #1 piston is at TDC on compression as advised in reply #2)

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Eric Russell ~ Mebane, NC
1961 MGA #61, 1981 Alfa Romeo GTV6, 1984 Alfa Romeo Spider, 1991 Honda ST1100

So i thought the distributor only fit in the engine one way. Its possible i need to pull and reset?

The drive gear can only be installed in 2 positions
Not many
It (the distributor)can only be inserted into the block one way
That being the right way or the wrong way depending on the drive gear orientation
Which is as above one of only 2 choices

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1957 Series 1 Land Rover electric VEHICLE CONVERSION

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Edited 1 time(s). Last edit at 2017-06-22 08:11 PM by ohlord.

The drive gear has nine teeth, thus I would assume it could be installed in nine different positions. I'd call that 'many'.

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Eric Russell ~ Mebane, NC
1961 MGA #61, 1981 Alfa Romeo GTV6, 1984 Alfa Romeo Spider, 1991 Honda ST1100

You would assume Butthe drive dog can only go 0 degree or 180 out
The shape of the dog makes it drop in only one way.
If the drive is 180 out it will drop in 180 out
2 positions isn't many
And only 1 is right
unless you desire positioning the spark wires 180 out

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LNDRVR4X4.COM
Home of Project "INCARN8'


1957 Series 1 Land Rover electric VEHICLE CONVERSION

FIXITUPCHAP.COM
FIXITUPCHAP INCORPORATED

RD3 Radar/ Electronic Warfare Technician
VIETNAM 1969-1972



Edited 1 time(s). Last edit at 2017-06-22 08:36 PM by ohlord.

9 teeth correct. But the top of the gear has a notch that fits into the base of the distributor and it will only go one of two ways. So, no matter where the distributor drive gear is on the cam gear, the rotor will only end up in one of two positions.

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Bruce E. Cunha

I've spun the engine around and I'm confident im at the top of the stroke on #1, it's still at the 5 o clock.

Btw, what's a dizzy?

What would happen if i put 1 at the 5oclock and go accordingly?

We're talking two different items - the distributor driven gear that meshes with the camshaft drive gear can be installed incorrectly. Once the drive gear is installed the distributor drive dog will only mesh in one position due to the offset. I am referring to the drive gear being installed incorrectly. Eight ways are wrong, one way is 'right'.

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Eric Russell ~ Mebane, NC
1961 MGA #61, 1981 Alfa Romeo GTV6, 1984 Alfa Romeo Spider, 1991 Honda ST1100



Edited 2 time(s). Last edit at 2017-06-22 09:07 PM by ghnl.

Slang for distributor.


Your car will run fine.

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Eric Russell ~ Mebane, NC
1961 MGA #61, 1981 Alfa Romeo GTV6, 1984 Alfa Romeo Spider, 1991 Honda ST1100



Edited 1 time(s). Last edit at 2017-06-22 09:00 PM by ghnl.

Rob....are you saying the drive spindle can only be installed correctly or 180 out? Are you saying it couldn't be installed one or two teeth off (for example), which would be 40 or 80 degrees off? If so, please explain why the spindle can only be installed in 2 positions instead of 9.

The stud that you screw into the drive gear is a handle for taking it out and also for putting it back in. The gear twists slightly both coming out and going in, so it may take a few attempts to get it correctly located. I don't know if that part of the engine design changed from the engines in the Austin Devon or Somerset, but without the handle on it is possible, in the older engines anyhow, to drop the gear directly down into the oil sump if you try to drop it in without the handle. Then you drop the pan and fish it out. It makes a long messy job out of a short clean one.

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My mechanic told me, "I couldn't repair your brakes, so I made your horn louder." (Steven Wright)

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“There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” Will Rogers

Indeed, if you try to insert the drive gear without using a long bolt/stud as a 'handle' you will next be finding out how difficult it is to drop the oil pan with the engine in the car.

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Eric Russell ~ Mebane, NC
1961 MGA #61, 1981 Alfa Romeo GTV6, 1984 Alfa Romeo Spider, 1991 Honda ST1100

To clarify:-

The drive shaft / gear whatever you want to call it, engages with the camshaft. Because it has 9 teeth it can be oriented 9 different ways. This drive shaft has an offset slot on the end furthest from the gear. This offset only allows the dizzy to go in in one way, no other way is possible, short of inflicting serious damage. There is a procedure to fit the shaft so that the rotor button points approx to 1 o'clock, however, the car can run with the rotor button pointing to any of 9 positions, but then the HT wires need to be plugged in so that wherever the rotor points to is set as #1. In your case at 5 o'clock. The engine doesn't care, as long as the wires are inserted in the correct order and hole. If you want to be "correct" it is possible to remove the drive shaft and start the insertion process again. To do this you need to remove the dizzy and the fitting the dizzy fits into. Then using a long threaded rod, of 5/16 X 24 threads you can remove the drive shaft and reinsert it.
The manual tells you how to orient the drive shaft, but if you are happy with the HT wires not being in the "correct" position then there is no problem.

Herb

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