John Fredrikson wrote:
>
> Well, the fuel lines checked out OK. There weren't any kinks. I disconnected
>the
> vent lines (the ones that connect from the carbs to the charcoal canister)
>and it
> started and ran fine. There was a kink in the vent hose from the carbs
>(HIF-4's) to
> the canister so I replaced the line. I still could not get it to run for more
>than
> 30 seconds. By adjusting the carbs I was able to get it to idle (roughly)
> eventually, but when I reved it up to about 3500 RPM it would die. When I
>disconnect
> the vent lines I am able to get a decent idle. How exactly are the vent lines
> supposed to be connected? Is there another way I should try to connect them?
>I'm
> open for suggestions (except if they involve a Webber purchase.....for now).
>
> Thanks,
> Fred
>
> William Schooler wrote:
>
> > John,
> >
> > Bob's suggestion was a good one. If, however, you find the fuel pipes
> > undamaged, suggest you double check how you have the fuel lines hooked up to
> > your carbs (HIF-4s?). In particular, check that the overflow hoses are
>properly
> > hooked up. I have heard of instances where the overflow (vent) line was
>hooked
> > up "back-to-back" between the two carbs, thereby creating an overpressure
> > situation in the top of the float bowls. This must be close to atmospheric
> > pressure for the mixture to be correct.
> >
> > Bill
> >
> > >>> John Fredrikson <jtfred@on134th.com> 07/09/98 09:00am >>>
> > I had last Thursday and Friday off last week, so I thought I would
> > finally replace the clutch on my 72 B so I could drive it on the Fourth.
> >
> > The clutch replacement went OK. I had a little trouble getting the motor
> >
> > back in alone, but it wasn't too bad.
> >
> > The problem is that now the car won't run for more than 30 seconds
> > before it dies. If I try to start it immediately after it kills, it
> > won't start. If I wait a minute while the fuel pump (non SU after
> > market) runs, it will start and run for about 30 seconds. It has to be a
> >
> > fuel supply problem. At one point when it started to die I sprayed gas
> > into the carb and that kept it running. I pulled the fuel supply line
> > from the carb and it is putting out plenty of gas. The fuel filter is
> > only a month old and looks OK.
> >
> > I have tried:
> >
> > adjusting the floats
> > new float bowl valve (from Grose jet to original style)
> > new needles
> > new fuel pump
> >
> > At this point I am at a loss. All I did to the carbs for the clutch swap
> >
> > was to remove them and replace them. I didn't do anything to the pump.
> >
> > If any of you have any suggestions I'll try anything at this point.
> > Please send reply's to my address as well as the list since I have just
> > started a new job and I'm way behind on reading the digests.
> >
> > TIA
> >
> > Fred
Fred,
I checked John Twist's Tech Booklet, but I'm not that familiar with the
HIF-4 carb, and the configuration of the Evaporative Loss Control System
on the '72 model. I'll hazard a guess or two and hope that the experts
from the list confirm or reject!
You should have one charcoal cannister. Three lines hook up to it, but
I can't tell you which line goes to which port! One line comes from the
fuel tank, through the separation tank. Another line comes from the
float vents on your carbs, and the last hose connects to the valve cover
on the engine. One other hose is involved, but it doesn't connect to
the cannister. It runs from the oil separator/flame trap on the lower
left hand side of the engine to the carbs.
The system is closed, i.e., the fuel cap and oil filler cap are not
vented. The only way air can flow into and out of the system is through
the charcoal cannister - the base of the cannister is vented. Without
going through John's excellent explanation of how the system functions,
I'll jump right to what seems to be your problem. He describes, under
"Common Faults", an obstruction to air flow through the cannister due to
the cannister having been filled with gasoline and the felt pads inside
becoming saturated. This results in a slight vacuum at the top of the
cannister which is transferred to the fuel bowl. Result is lean
running, or surging.
Unfortunately, John doesn't say anything about how to fix the cannister.
I suppose you could just get another one, but I seem to recall quite a
discussion on this list (or the MG BBS) about how to renew one of those
things with fresh charcoal, etc.
If someone out there can take over from here and talk Fred through
fixing this cannister thing, I'd sure appreciate it, and I know Fred
would! Hope I've been of some help.
--
*Bill Schooler *Check the MGCC Wash DC Centre Web Page
*Woodbridge, VA *http://members.aol.com/mgccwdcc/
*schooler@erols.com
*53 TD
*60 MGA
*69 MGB/GT
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