Here's what I did today...
I've already replaced the coil, so I went ahead and replaced the condenser
which is about the only thing that I didn't replace before. The problem
kept coming up, except it happened while the car is idling a number of times
(I kept running it and it would run for maybe 5-10 minutes each time before
bonking out).
I then went to the fuel system (because I would notice that the fuel pump
would pump like the bowls were empty when I turned the ignition back on). I
started watching the fuel filter that I had put in. I watched as it pumped
through, but it stopped after a little while (as if there was no pumping).
I also did this with the gas cap off to make sure there were no ventilation
problems with the tank, but the same problem kept arising. Then, I took off
the fuel filter and put the regular line on thinking that the filter was
causing a sort of blockage making the fuel pump think the bowls were full.
This still didn't fix the problem.
The main thing that is odd about this is, is that after it quits, I'll turn
off the ingnition...as soon as I turn it back on, the pump pumps like the
float bowls are empty (which is I guess true). Sooo...basically the car is
starving for fuel for some reason. Could it be the new float bowl needles
sticking that I put in? (they are new, but when I played around with one,
it seemed to stick every now and then, but I thought that it wouldn't stick
enough to hold back fuel). There doesn't seem to be much gunk down in the
bowls, but that wouldn't be the problem if they empty out.
The problem is somewhere from the bowl needles back. I don't think it's the
ventilation in the tank as I took off the gas cap to see if it was getting
enough ventilation...but that didn't seem to work (as mentioned above). It
wasn't the filter as I took it off. Hmmm...it can either be the pump or the
float needles from what I can tell..because it definately seems like it is
running out of fuel.
I was thinking as a guy had said ealier that 99% of the time, the pump
either works or it doesn't, so I'm turned off by the idea of the fuel pump
going out intermitently. The needles are new, but it does seem to have a
slight sticking problem when I play around with them...but it didn't seem
like enough to hold back fuel if the float was down. Could my float be
sticking? How would I tell?
Could it be the needles? Should I get the groose needles instead? Could it
still be my ignition system breaking down (even though it sounds more like
it's starving for fuel)?
Hmmmm...I dunno...any other ideas? :\
Keep the ideas coming, because I'm always open to new ones. :)
Blake Wylie
70 MGB
At 01:31 PM 1/14/98 -0600, Bill Eastman wrote:
>Blake,
>
>Another thought- electrical components often crap out with heat. In
>particular, original Lucas electronic ignitions are prone to this. Maybe
>your coil, condensor, or electronic ignition (if so equipped and yes I know
>that 70 MGB's don't have electronic ignition. I used to own one) is puking
>on you once it gets hot. Condensers are cheap and coils aren't too be
>either so you may want to thow one in to check it out. If your car
>originally had a ballast resistor and it has been removed, your coil could
>be susceptable to overheating.
>
>I find it interesting that your old tank was not vented. A 70 B should
>have one of those neat in trunk vapor separators and a charcoal cannistor
>up front as well as an air pump.
>
>I would question whether the problem is a fuel pump issue or a float bowl
>issue because of how long it takes to crap out. if the fuel pump couldn't
>keep up, it would not take long to run the float bowls dry. An
>intermittent issue with the floats would be just that- intermettant and you
>would not see the consistency of the engine bonking after 15-20 minutes. I
>suppose that a slight leak in the supply line to the fuel pump could make
>it work hard enough to overheat but I expect that you replaced all of that
>when your replaced the tank.
>
>The next time it quits, listen for the fuel pump. If it is still running,
>you may be running the float bowls dry. My bet would still be tank vacuum
>or electrical.
>
>Regards,
>Bill Eastman
>
>
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