> If a seat problem is bad enough to cause
> driveability problems, a compression check (or, preferably, a leak-down
> test) should show leakage.
If it's bad enough to cause that much trouble, then just putting air pressure on
the cylinder (ala leak-down test) should produce a definite hissing in the
intake or exhaust.
> It's probably only necessary on the
> exhaust seats, and, given the width of hardened seats, it's not the
> easiest thing for a shop to do to replace intake and exhaust, since it
> probably would mean that the replacement seats have to be siamesed to
> fit (depending, of course, on availability of seats in your area).
I've been told that the siamesed seats are also more apt to fall out later.
However, if it's an intake seat that is damaged/cracked, the only alternative to
siamesed seats may be a different head (or no "unleaded" conversion on that
cylinder).
For those who are wondering, 'siamesed' means the seats touch each other without
intervening head material. Usually they have to be ground flat where they meet,
too.
> The other very obvious thing to examine is flow out of the #2 injector.
> If it's partially plugged with crud, it can cause the same symptoms. A
> compression check should answer that question. If the compression is
> good, and the spark is good and the spark plug is good, you might
> consider having the flow to that injector checked and flow through the
> injector tested.
>From what (very) little I know of the Lucas PI, the metering unit can also
>cause
low fuel to one cylinder. And the original seals would not stand up to modern
fuel additives.
Randall
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|