Message text written by "Wages, Jeffrey"
>I just picked up a 'new' 73 TR6 and had a weird experience in her the
other
day. While cruising up the highway at @95mph the engine began to sull.
Almost
like it was starving for fuel. My first thought was that the 1/4 tank
reading
on the gauge was inaccurate and I was running outta gas. As I got off the
highway it idled ok. Then as I proceeded through a neigborhood it began
doing
it again until it eventually died. It would idle but any attempt to give
her
gas and she would die. I got out and checked the tank...there was plenty of
fuel. I popped the hood and noticed the fuel lines just before the carbs
(ZS)
appeared dry. My mechanical fuel pump has a primer pump so I pumped it a
few
times and saw fuel move through the lines. I got back in and fired her up
and
she ran fan (though I was cautious) the rest of the way home.
My first thought was the fuel pump but I'm not sure why it would start
working
again (unless by priming it I performed CPR). My other thought was that I
might have gotten a vapor lock from the heat of the manifold to the bowls
of
the carbs. We used to get this with some Weber carbs on Hondas we raced.
Are
TR's known for this?
The fuel tank appears to be from an earlier model and has no rust. There
are
two vapor tubes at the top of the tank. One is plugged with a rubber cap
and
the other has a hose draining out under the car. Is one tube open enough
to
prevent a vacuum?
Anyone have any ideas?
<
Jeff, I suffered the same symptoms and eventually converted to an electric
pump for this and other reasons. My current operating theory is that the
new gas formulations cause the 30 year old diaghrams to harden and the
pumps don't pump like they should. The priming lever will extend the pump
more than the cam so operating the lever will not only move the diaghram
over a larger range allowing the pump to actually pump but may also limber
up the diaghram and the pump will start to work again. But I suspect that
over time the diaghram will eventually crack and start to leak fuel into
the crankcase.
I guess the short answer is I suggest you either rebuild the pump with a
new diaghram or fit an electric pump. I went the electric pump route on
the TR6 but I rebuil;t the stock pump on my TR3 (which also exhibited the
same symptoms)
Good luck
Dave Massey
71 TR6
57 TR3
80 TR8
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