You say you checked timing. Have you checked that the advance comes in as
intended? I would look at that, fuel pressure, and the coil in that order.
John
Mark Clark wrote:
> Okay, here are the symptoms:
>
> The car ran well last summer. No engine work over the winter. It has been
> running poorly this summer.
>
> Engine starts with no problem. Idle is reasonably smooth. When driving,
> it feels like the engine goes down on power (hesitates) every so often - as
> if it was not getting enough fule intermitantly. It does not stall. The
> hesitation comes on both acceleration, steady cruising, and when I take my
> foot off the gas. The hesitation is random, and occurs fairly often - no
> more than twenty-thirty seconds go by between hesitations, and they
> normally come more often. Pulling out the choke makes no difference.
>
> Here is what I have done:
> -checked valve adjustment and compression - both fine
> -gapped plugs
> -checked and tightened all ignition leads and connections to the coil and
> distributors
> -replaced points with electronic ignition - no change in symptoms
> -adjusted carb float levels
> -carbs were rebushed several years ago - no air leaks
> -mixture needles were replaced last year and the car ran fine after that.
> -carbs adjusted and syncronized with Unisyn and the clear spark plug jobbie
> I can't remember the name of
> -checked timing
> -got a new tank of gas and added gas additive to dry and clean gas
> -replaced fuel filter
>
> I suspect an electrical problem. Distributor cap, rotor, plugs, and plug
> wires have all been replaced in the last several thousand miles. The only
> electrical device that has not been replaced is the coil, a Lucas
> high-voltage unit.
>
> 1) Could it be the coil? Can I do any tests to see?
>
> 2) Anything else I should check?
>
> Thanks much - look forward to your reply.
>
> Dr. Mark Clark
> Oregon Institute of Technology
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