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Re: B problem -Reply

To: schooler@erols.com
Subject: Re: B problem -Reply
From: John Fredrikson <jtfred@on134th.com>
Date: Fri, 17 Jul 1998 09:15:58 -0400
I'm not sure if my car came with a run on valve or not. When I got it there 
wasn't one on
it. I talked to a guy at a local LBC shop and he recommended I remove the hose 
from one
of the carbs and blow into it to see if there was resistance. There didn't seem 
to be
any. When I was about to try again to tune it, I noticed that I couldn't adjust 
the
needle seat above the bridge. I had to remove the carbs to get it un-stuck. 
When I
replaced the carbs, I forgot to attach the vapor lines and noticed that when I 
reved the
motor, gas would shoot out the back carb. I don't know if it was shooting out 
front (I
didn't like the idea of gas spraying all over). I'm thinking that I had better 
check my
float level again.

Fred


Bill Schooler wrote:

> John Fredrikson wrote:
> >
> > Thanks Bill and Rich. I'll have to check again how the canister is 
>connected. I
> > think there are two lines connected to it at the moment. One from the carbs 
>and one
> > from the tank. The third (the largest) is plugged (by the PO). There is no 
>anit
> > run-on valve connected to it. I suppose it too was removed by the PO. Is 
>there a
> > good way of bypassing the canister? Is it needed or just another part of the
> > emission controls (most of which has already been removed by the PO)?
> >
> > Thanks again,
> > Fred  -  who is about ready to schedule an appointment with Quality Coaches
> >
> > Rich Mason wrote:
> >
> > > At 08:46 AM 7/14/98 -0400, you 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
> > >
> > > Fred -
> > >
> > > I've missed some of the thread but one thing I haven't heard any mention 
>of
> > > - the solenoid "anti run-on valve" that prevents run-on after the engine 
>is
> > > stopped.  It is mounted on the front bottom of the charcoal canister and 
>is
> > > triggered by the ignition switch and oil pressure.  I don't have my manual
> > > handy - but you might want to check if it's functioning properly.
> > >
> > > My understanding of how this works:  Under normal operation, the valve is
> > > closed when the engine is running.  When you turn off the ignition, the
> > > valve is energized (opened) until the oil pressure drops down to a very 
>low
> > > pressure, then it is de-energized(closed).  If you listen during shutdown 
>-
> > > you can hear the solenoid valve click shut as the oil pressure approaches 
>0.
> > > The opening of the valve vents the carb - preventing run-on.  It sounds 
>like
> > > your valve is open all the time causing a very lean condition.
> > >
> > > Good luck,
> > >
> > > Rich Mason
> > > '73 MGB
> > > Madison, AL
> > > ------------------------------------------
> > > e-mail--> rmason@ro.com
> > > MG Page-> http://ro.com/~rmason/mgpage.htm
> > > NABMS --> http://www.geocities.con/MotorCity/Garage/5207/
> > > ------------------------------------------
>
> Fred,
>
> I don't think your car was equipped with the "run-on" valve.  Believe it
> began appearing on the '73 model.  The plugged connector on your
> cannister should have a hose running to the tube on the rear of the
> valve cover.
>
> As John Twist mentions, the vapor control system has nothing to do with
> the "active" emission control system, i.e., the air pump, gulp valve,
> and all that.  It is a good system to have installed and functional and
> has no effect upon the performance of the engine whatsoever.  Recommend
> you unplug that port, connect it to the valve cover and see how your car
> runs.  If it still exhibits the symptoms, I would imagine the cannister
> needs to be replaced.  You might also consider "blowing out" all the
> lines to make sure there is no blockage in any of them - particularly
> the one to the tank!
>
> --
> *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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