Jack
Don't really know about the TR-6 but we have been having similar problems
with our FP Spitfire.
We have blamed it on the float bowl levels, particularly indicated by the
car flooding on right hand curves and taking a while on the straight to
clean up. When we move the piston up and let it fall gas is pumped out the
jet. We lowered the fuel level in the float bowls until the level was just
even with the bottom of the restriction in the jet, relying on capillary
forces to bring the fuel higher. It seems to have cured the problem. To
some extent this seems to make no sense since the engine tilt is only about
4 degrees and we go up and down hills much steeper, but it seemed to work.
We use MGB 1.5 SU's with Spitfire float bowls and set the floats at about
0.250 inches, deeper than the manual.
----------
> From: Jack Wheeler <jwheeler@robus.com>
> To: 'FOT' <fot@autox.team.net>
> Subject: TR-6 Technical Question
> Date: Wednesday, December 08, 1999 6:21 AM
>
>
> ------ =_NextPart_000_01BF414C.DB929580
>
> I have encountered a problem with a 1974 TR-6 I am working on, and am
> hoping someone out there may be able to help me out.
>
> Everything on this car has been rebuilt, including the engine and carbs.
> I'm now trying to tune the carbs. I have disconnected the linkage
> connecting the two carbs and adjusted each separately so that they are
> pulling the same amount of air at idle. With the engine warm, I check
the
> mixture in each carb by lifting the piston about 1/4" (per the workshop
> manual). When I lift the piston in the rear carb, the idle increases,
> indicating a rich condition. Therefore, I have adjusted the needle all
the
> way down to the bottom of the piston (i.e. as lean as it will go), and
this
> test still shows a rich condition.
>
> The front carb is the opposite. When I lift the piston, the engine dies,
> indicating a lean condition. I have raised the needle in this piston as
> far as it will go (i.e. full rich), but the engine still dies when I lift
> the piston, indicating too lean.
>
> Most of the work I have done on these cars has been on the TR-2/3/4
series
> which had no emission controls. Could the emission controls be causing
> this problem? I have kept all of the original vacuum lines in place.
>
> Also, when the engine is cold, it will backfire out of one or the other
> carb when I blip the throttle. The ignition timing is set for 30 degrees
> at full advance, and the advance curve seems to be OK (i.e. it drops back
> to near TDC at idle).
>
> I would appreciate any suggestions from the FOT group as to what might be
> causing this problem. Many thanks.
> ------ =_NextPart_000_01BF414C.DB929580
>
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> ------ =_NextPart_000_01BF414C.DB929580--
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