To this oh-so-knowledgeable list ---
Heres a follow-up to my posting from back in June.
I had been diagnosing stumbling at high RPMs in my '66 BJ8
and had managed to improve things only to discover that when
things got hot, things got worse.
The list came through, as always, with plenty
of suggestions including:
Check fuel pump for dirt?
Fuel lines dirty?
Gunk in the fuel tank?
Valve clearance when hot leaving valves slightly open?
New distributor cap?
New solid core wires?
vapor lock?
blockage in exhaust (temp?)
Gas tank venting?
Pipe to second carb clogged?
Mesh filters in banjos?
Inline fuel filter?
Check heat shield?
Set idle mix when warmed up?
Fuel pump delivery?
Dent in fuel line?
Fuel/tank delivery?
I had already changed out many parts, checked numerous previous
suggestions, etc. But I took the suggestions to heart and found
out more about my BJ8 than I knew before (easy to do.)
I tried to address all the suggestions including a check of the valves
when hot (OK), looked for a crimped fuel line (found two spots), reset
the dynamic timing with an accurate advance timing light, replaced the
coil (again), replaced the ignition (solid core)
wires and distributor cap (again).
All the "fixes" had noticeable but minimal affects.
I did drain, flush and replace the antifreeze mixture with almost
pure water and water-wetter. The BJ8 has never run cooler and Im
convinced this has made the overall condition far less aggravated.
But the one item which seemed to turn the trick was the part I took for
granted (of course.) One day while driving to
work, the healey stopped running.
Engaging the starter revealed a strong battery and a motor which would
still turn over but would not fire.
The stoppage was immediate no stumbling or start/stop --- it just quit.
Being in rush hour traffic and only a few miles from home, I called for
a flatbed and went back home. It didnt take too long to determine
the distributor rotor had failed.
One of my co-workers later joked that now, instead of an intermittent
failure --- I had a steady state one which I could diagnose.
His comment was more telling than he realized.
Replacing the rotor not only brought my BJ8 to life and but it now
runs at high RPMs without a hint of missing.
Even the shifting seems smoother and more reliable. Is it possible
that the spark was so irregular that I did not realize how poorly
the car was running at all RPMs? Seems unlikely but the difference
is significant. No more RPM governor on this 66 healey!
The rotor was new having been replaced when I started all this.
Another good reason to change one thing at a time --- perhaps if it
was bad from the outset I would have realized it back then but I suspect
the rotor has been progressively failing and, until it failed completely,
I ignored the possibility of its being a major
cause. And why I did not change
it as I worked through the rest of the ignition?
Well it won't happen next time!
Live and learn --- I sure did!
Thanks to Alan, Udo, Fred, Bob, Ben, Simon. John, Chris,
Bob, Philippe, and all the others who contributed suggestions
and potential remedies. I am extremely grateful to have had your help.
-pd-
1966 BJ8
Upstate NY
|