I have a Mallory single point centrifugal advance distributor in our 1929 Ford. The distributor has electronic (unilite) ignition. I was checking the timing and when she fires, as I accelerate, the timing first goes backward - retards then at a certain rpm it starts to advance. I checked the 2 springs and the plates and all seems fine? Help please!
Does it run? And stumbles when you rev it? Did you drive it in or just installed it. I've seen it a couple of times, that a Bosch 009 distributor for a vw bug is mistaken for a Bosch counterpart for a Volvo b18d sport. The look a lot a like, except the turn apposite direction. I know that the the 009 is a good and popular match with a banger engine, so maybe you got a distributor meant for a Volvo, made by Malory, and the seller didn't know. If I'm totally off, feel free to ignore me.
You failed to tell what engine is in your 29 Ford,,Is it a stock 4 cyl Modle A engine or something else??
I have a timing guage mounted and I put a timing light on it. You can see the timing retard and at a certain rpm it advances back to where it should be.
is it a complete Mallory Dist for the modle A or a stock modle A dist with a Mallory conversion in it? You are aware that a stock modle A dist has an adjustment screw under the rotor?..Pull rotor and look at it...maybe its loose
On a Model A distributor end play won't change timing. The distributor gear drive is located in the valve chamber and the direction of rotation tends to favor additional advance if the drive develops end play. I suspect the spring in the timing cover that is intended to control end play in the cam has broken and your cam is walking back and forth in the block and affecting your timing. You might be able to check that without removing the timing cover by inserting the timing pin and attempting to feel for forward and backward movement of the timing gear as you change engine RPM. Another check would be to remove the timing side cover and watch it during operation, but that can get a little messy. Good luck!
Thanks 5280A2 So if I pull the timing side cover, do you think I would be able to check the cam for movement?
That initial retard may be built into your control mod, perhaps by design or perhaps by accident. OK sounds like if it is the control mod it is not by design, unless of course it is not an ignition problem at all and there is some other cause for your stumble.
would an erratic voltage to the control module do this? generator needs the rpm's to produce enough volts?
You should be running off the battery. The battery is a buffer between the voltage supplier and the end user.