I've got a 1962 Ford Uni with a FE390. Nothing over the top but runs strong. Riding around this weekend i noticed that as Im driving at a steady speed, Say 60 mph there is some misfiring maybe hesitation or something going on. However, when i accelerate out of it all goes well. Idles good, starts good accelerates good. Steady, then it was missing. However, i took the vacuum hose off the dizzy and plugged it at the carb and seemed to fix it. I don't want a band aid to something if there is more to it. Any ideas or someone have that happen? Spark plugs looked good and all ignition parts are less than a year old. Could be carb...
Sounds plausible... And as you accelerate when it's missing the manifold vacuum drops and the timing retards a few degrees. Easy to test the theory by retarding the initial timing by a few degrees and see if the problem goes away. Maybe find a different vacuum advance unit with slightly less advance built in. This would allow you to maintain your initial and part throttle timing where the engine's happy.
How old are your wires, plugs, coil, points and condenser? The condenser or coil don't have to even be old to be going bad with all the overseas shit now days.
OK ill try that. I had the dizzy customed to fit my trucks specs. Has ran great up until this weekend. Well still does until i get to cruising speed. I would say less than a year old. I a pertronix unit int eh distributor but i checked the spark plugs and wires and all was good. I was thinking of that but why would it be good on idle start up and acceleration unless it was getting full voltage to the spark plugs until; i got on it. I was thinking ignition but a buddy said he thought mroe carb. Its a Holley Street avenger.
Did you maybe get a tankful of gas from someplace where you don't normally fuel up? Could be as simple as that, I suppose. Are you hearing any pinging that you didn't before the miss started?
Is it missing under a load or just at cruise? I was also thinking too much advance, but usually feels like it's surging instead of a miss.
I also am running that last tank out for that reason. That morning i put a small amount of octane booster in the tank. I just filled up again but still had the vacuum unplugged and parked it last night. No. Runs great under load. Only at cruising at 50 or so and above. I noticed a small kink in my fuel line from the pump so i changed that just in case it was pinching the flow off a tad. No change. I mean it could have been a surging but really felt as if it was just missing a part of the spark or loss of fuel for a certain second. Weird that if i hit the gas then it goes great. i wouldnt think so because when i unplugged the distributor vacumn it ran good. Wouldnt it always be hisitating. God i hope not anyway.
Ive had the same size jets in it for quite a while. never had an issue. I did think maybe the accelerator pump diapram may have a small tear or soemthing. Thats more of a bogging feeling though yeah thats a good idea. Maybe thats why when i unplugged it it bypassed it.
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