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MG TD TF 1500 - Distributor Advance Springs
|I have been problems with my distributor. Even before I installed a pertronix ignition, (as I know remember, it has been a year) I have had trouble getting the timing set properly. If I use a light and statically set it to TDC or slightly before TDC it won't even start, and once even backfired, trying to run.|
If, however, I loosen the clamp and turn the distributor counter clockwise, which I think would retard the timing, it runs pretty well, and I do believe that I could use trial and error to get it to run really well.
When I removed the plate to install the Pertronix, I noticed that there was a fair amount of play on the weights (at rest). Perhaps as much as 1/4" if you pushed them lightly with your finger. I am wondering if the springs are stretched out. Aren't the weights held fairly firmly together at rest ?
I am wondering if this would account for the behavior. If the timing were advanced by loose or too long springs, then I would have to retard it in order to get the car to run correctly.
Any ideas ?
|I would be more inclined to think that you have two of the heavy springs that are supposed to fit loosely and then tighten up as the rotational speed increases. What you need to do is get with somebody that has spare dist. and compare springs. Or there was a thread on here a week or so ago that mentioned a fellow who had some springs made that gave the correct (50 year old) advance curve.|
I still think that a new curve would be better, but have to find an engine dyno and a freshly rebuilt engine to conduct the test.
Anybody out there got any ideas on how to accomplish this?
|R. K. (Bob) Jeffers|
|Your distributor originally came with one light and one heavy spring. That means only one spring applies pressure at idle, and when it fatigues (10-20 years into its life span) your ignition curve will drift off course significantly. Beware of the replacement springs that you can buy - they're almost never right for your application. Unless you can test the ignition curve before you start your car with the new springs, you're risking damage from a rich or lean condition caused by incorrect spark timing. You WILL need a good timing light, preferably the dial-back type so you can read the amount of advance your distributor offers at different rpms.|
This thread was discussed between 22/01/2008 and 30/01/2008
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