>
> Uh... Amanda is pinging, dieseling when shut off, and has a fast idle,
> among other things. If she is supposed to have a vacuum retard, and it is
> disconnected, my (perhaps naive) reasoning is that timing would be too
> advanced under high vacuum conditions (e.g. at idle, or on overrun). And
> I would think that *would* cause some or all of the symptoms. Have I
> reasoned incorrectly, and if so, how?
>
Okay, not only do the symptoms match a vacuum leak, they also match a way
advanced timing setting. Your reasoning is basicly sound. However... :>
Truimph did not put in the vacuum retard for engine running or longevity
reasons. It's there solely for emissions. The TR6 motor is quite happy
running with a idle timing of 10 before; a whole lot happier than with the
4 after. This is what that retard does. It sucks the timing back 12-14
degrees at idle and light throttle cruising. Bad for response to minor
throttle changes, *bad* for fuel milage, good for emissions.
So a TR6 will actually run better with the retard disconnected. It will
idle so much better that you may not be able to get it slow enough. And
disconnecting the can should not cause any dieseling or pinging. Especially
pinging. That happens under higher loads, when the retard is inactive anyway.
Let me revise what I said. Your symptoms match the classic case of a vacuum
leak, or seriously advanced timing. Some possibles:
Vacuum leak:
hose off
blown brake booster
torn carb diaphragm
mucked up needle/seat or float (lean mixture, same result)
carb mounts loose, ready to fall off (I have seen this!)
Timing way off:
breaker plate broke
" " locating spring on vacuum can broke
point gap open too much (probably take a gap of like .100")
centrifugal advance stuck full on
distributor got unhappy with the scenery and decided to rotate a little.
cam timing jumped
And one other possibility is a total loss of coolant.
Randy
randy@taylor.wyvern.com
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