QuestionFirst, I would like to thank you for such a helpful website!
Thanks a lot!
Recently bought 79 MGB that has a dual point distributer. Did not run when I bought it, but after palying for an hour or so I got it started. After another hour or so got it running very well after removing both sets of points and sanding them down and replacing them. (Auto parts stores locally did not have any new contact points) The next morning it ran bad so I decided to replace the distributer. Now here is what I want to know. I am guessing the old dist was a Mallory dual point version. The new one I got is a Lucas True Spark ignition #41427E electronic dist. with a vacuum unit attached. (the old dist did not have any vacuum fitting). When I removed the old distributer I had the rotor aiming directly at the #1 spot in the distributer and I noticed that the dist. shaft was at about a 30 degree angle when removed, but the new distributer with rotor aiming at the #1 wire position the angle on the dist. shaft is just the opposite or about a 330 degrees angle.
Needless to say, it doesn't want to start.
Maybe I need the procedure to re-install the new distributer from scratch.
Thanks again for your great website and your time!
AnswerHi Dave,
You can't expect two different brands of distributors to be oriented the same, it just will not happen.
You need to set it up to be timed correctly and that is not hard. The Lucas distributor drive is a center shaft and a blade that is off-set so it will only go in one way and can not be put in 180 out.
First thing to do is remove the plugs and put the car in 4th gear with the brake off and on level ground. Put your thumb over #1 plug hole while you and/or a friend roll the car forward. When #1 piston comes up on the compression stroke you will feel the pressure on your thumb. Stop and put a thin rod like a coat hanger in #1 plug hole to feel the top of the piston and slowly roll the car forward until you feel that the piston is at the top, then stop.
Now slide the dist. into place so the vacuum unit does no foul on anything. Take the dist cap off and look where the rotor is pointing. Turn the dist so the rotor points directly at one of the four pegs for the plug wires. Now, put #1 plug wire in that position and follow around the cap going counter clockwise with the other wires. (1,3,4,2 firing order) If the wiring has not been altered for the aftermarket dist that was in it, you should have two white w/black tracer wires on the negative side of the coil and it should be a Lucas 6v coil. There should be two white w/light green wires on the positive side of the coil. If the wires are as I said you can proceed but if they have been altered you need to stop and get a wiring diagram and correct the wiring before proceeding or you could do some damage to the system.
If the wires were correct you can put a timing light on #1 plug wire and put a plug on each wire and lay all of the plugs on a metal part of the engine. Roll the car backwards so as to turn the crankshaft pulley no more than 90 degrees. Now turn the key on and move the car forward by just bumping it lightly forward and watch the timing light for a single flash (which should happen in about 70 to 90 degrees of crank movement) As soon as you see the light flash stop and look at the timing marks on the front cover and the notch in the front pulley to see where the timing is now and adjust accordingly and back the car up and do it again until the timing is exactly to specs. Which is 10 deg BTDC. Once it is correct you can tighten the dist and replace the plugs and start the engine and recheck the timing at idle to be at specs. The specs under the hood over ride what any book says but if that is gone set it at 10 deg BTDC.
Let me know,
Howard
