Hi-
Well thank you for all of your great advice, there were quite a few
things that were pointed out that I had not yet checked such as the
clogged float valves and a possibly damaged ignition coil. It was
interesting to see that it is always difficult to separate these
problems into either fuel or electrical judging by the symptoms. This is
not a good thing since working on these two respective systems takes to
very different approaches.
Well anyway, my problems were due to self-inflicted fuel vapor lock. I
had replaced the mechanical fuel pump, which had failed resulting in a
tow truck adventure, with an electric one. I had taken the lower section
of an old stock fuel pump and made it into a mount for the electric
unit. It came out looking very nice for a visible modification but I had
neglected to consider what effect the engine heat would have on the
pump. I also now recall that the electric pumps prefer to push the fuel
from the back of the car rather than pull it to the front even though
this Moss pump was advertised as being capable of doing either. This new
pump went in mid-winter and so I did not notice any problem in the
colder weather but as soon as it started warming up a little, things
went south very quickly and so I did not associate these problems with
the pump.
Anyway, I temporally moved it away from the heat source (engine) and
this problem pretty much went away. I am not ready to give up on this
pump though; I routinely drive some distances - From Ventura County down
the PCH, Malibu, to San Pedro for those of you that are familiar with
the area. It's a real nice drive but failures on that trip would be a
bummer and this pump seems to be a very reliable design.
I plan to relocate the pump to a cool spot where it can dissipate it's
heat into some cool metal, it's a bit of a challenge finding the right
spot in terms of practicality and appearance. There are some good
candidate locations. I will also bend up new fuel line such that it is a
little further away from the engine.
Even when I had the mechanical pump, my car would stumble on a hot day.
I am starting to think that this problem has always been there to some
degree. I had talked to a mechanic one day, some time ago, and he said
that fuel is more volatile than it used to be and this vapor-lock is
more of a problem. Our conversation had been from an emission
perspective but what he was saying was that our cars are not well
designed for today's fuel. He had mentioned that it can even now boil in
the float bowl now. I don't know if that is true or not but it has me
thinking.
Anyway, I am going to keep the pump up front still, it is a natural
place for it as I don't want to mess with the pristine rear section of
the car with all that cutting and drilling to mount the pump there.
Thanks again for all of the good responses.
Steve
'74 TR6
Channel Islands
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