Hi Paul,
What interests me is: what has remained the same on the car.
Did the basic ignition part stay on the car i.e. is the advance and
retarding part still the same? In the Dutch MGCC magazine a story was told
about ignition where most of these parts looked allright - but in the end
were not.
The experience was that just a few good guys (or dolls) were able to
properly repair this part of an ignition.
Cruising is still driving at reasonable high revs. Means the above mentioned
timing is involved. Vacuum advance seems to be o.k.
On Eric's car maybe leaky butterfly spindles in his carbs may be involved,
while the carbs were not restored recently - at least worth to check for
play.
Cheers,
Hans
'71 MGBGT covering the seats now making good progress.
(Lucky me I had the real original BL foam seat still at home)
> -----Original Message-----
> From: Paul Tegler [SMTP:wizardz@amdyne.net]
> Sent: Tuesday, March 09, 1999 07:50
> To: Eric Kutzli; mgs@autox.team.net
> Subject: Re: Lean at cruise
>
> too bad you are such a recent addition to the list
> I've been going through this for months.
> I've even bought new carbs, rebuilt the dizzy twice,
> EVEN CHANGED MOTORS (with O/D tranny)
> still does it.
> three different sets of plug wires
> 2 sets of plugs (different types) - multiple gap settings
> It's not fuel pump. It's not elec ign (tried two different ones plus back
> to
> points - no change)
> Strong acceleration - but stumbles at cruise
>
> Just got a line on a racer near me.
> Hopefully I will be able to have him look at this weekend
> Stay in touch If I find the problem I'll let you know.
> Your not (and I am not) the only one that has brought up this problem on
> the list
> -----Original Message-----
> From: Eric Kutzli <ekutzli@netins.net>
> To: mgs@autox.team.net <mgs@autox.team.net>
> Date: Monday, March 08, 1999 10:21 PM
> Subject: Lean at cruise
>
>
> >Hello everyone,
> > New to the list but have owned my 1974 B since 1994 and spent three
> >years in restoration. Any info appreciated on a problem that shows up at
> >cruising speed ( between about 50 and 60) The engine seems to miss on
> light
> >throttle going up hills. Under hard acceleration no problem, but to just
> >hold constant speed ascending a grade with gentle increase in throttle
> the
> >engine misses. One day just as a test I pulled the choke out to richen up
> >the mixture and the miss dissapeared. OK, so this suggests engine is
> running
> >lean.
> > I checked vacuum advance, timing, and HIF carbs. Smog pump and
> >associated technicalities were all removed by previous owner. I looked
> and
> >poppet valves in the butterflies are soldered shut. Idle is a little
> lumpy,
> >and seems hard to get idle mixture from running too rich ( according to
> >colortune) Ignition seems to be hot enough ( according to the
> oscilloscope).
> >
> > The final culprit is the carbs. The car has 68,000 mi and engine was
> >rebuilt 2,000 mi ago, but carbs were not. I have tried the old spray em
> with
> >something and see if the idle changes but can't seem to find the problem.
> >Idle is too rich and cruise is too lean. So if the problem is the carbs,
> >several questions come along A. to replace or rebuild. Is new better? Is
> >rebuild or just new needles only delaying the inevitable? B. SU or
> Weber?
> I
> >guess I really don't mind tinkering with the stock dual carbs. It's kind
> of
> >a badge of honor to keep them happy C. HIF 4s or HS4s? I have a set of
> >used HS4's on the shelf that could be rebuilt. Do HIFs have
> >problems/drawbacks in being designed for emissions compliance rather than
> >engine performance? Might even buy new HS4s?
> > I'm going to need to decide, my wife actually asked me what I wanted
> >for my birthday coming up soon, and someday the Iowa snow will melt and
> I'm
> >going to want to drive.
> > All two cent suggestions considered at current market value.
> >Thanks everyone,
> >
> >Eric
> >ekutzli@netins.net
> >1974 MGB "Maggie"
> >Now Glacier White - just couldn't talk myself into respraying the
> original
> >Citron...
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