Can't Get Enough
Join Date: Sep 1999
Location: Cotopaxi, Colorado
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Re: TR ignition upgrade - mileage loss
Before you do anything radical, like removing your upgrades, I would double check your dist. curves. I think that the key phrase here is the re-worked dist. Other than obvious carb problems, like the notorious Holly power valve leaking, most fuel econemy problems are related to the vacuum advance curve. Did you check the obvious fisrt? Is the dist. vacuum advance hooked up? Is it on a good ported signal? Does the advance even work? Some diagnostic time may be in order. Get a good timing light with a delay unit, and a vacuum guage and run some tests. CJ-8/5.2 MAG gave some good specs for timing.
Remember, when tuning an engine, you must do things in the proper sequence. First, is the engine even tunable? Mechanical condition of the engine has to be correct, and there were some older posts on using a vacuum guage to help diagnose mechanical condition. Second, the ignition must be correct. That means cap, rotor, wires, plugs, and all of the timing curves. The last step is the fuel system.
From the sound of your post, was the TR upgrade done the same time as the re-curve? I seriously doubt that improving your secondary output will cause a decrease in fuel econemy, but re-curveing the dist. will. Very few people know the proper way to do this, and most of the small improvements in drivability that are gained with a re-curve, are almost always associated with a loss in fuel econemy. Hope this helps, good luck!