Yep I'm back. ;)
Last night I spent the best $50.00 I've spent in _a g e s_. On the weekend I
fixed a carb throttle plate sealing problem, and of course I had to play
with the carb settings again didn't I.. <G> New dist. an all etc. Bored etc.
<G> (no Rugby on telly) Well I couldn't really get a good idle, but it was
'ok' - running out of time etc. The idle was a bit lumpy, and I was having
trouble tracking down which carb was rich with that lift the pin test.
Anyways, I was speaking to Hans in Melbourne about something else and he
said 'Why don't you get a Colortune, I use them all the time'. But I said,
Everyone on the Net says these are Cr*p! <G> He couldn't understand why and
uses these to tune everything from 948cc Sprites to MGC's. So while I was
buying some bits to make a recovery tank for the MGA, I plumped for a
In a word - Brilliant! So damn easy it's not funny, I had a brilliant idle,
and the right mix through the rev range in about 15mins flat. My front carb
was too rich, and the rear too lean. This is so excellent for fine tuning! I
can't understand how people can bag these - is it possibly unleaded vs
leaded fuel? Do they burn differently? Is that why people say they can't see
the colour? It was so easy to see the colour in my dimly lit garage. We
still have leaded fuel here in Aus. But anyway, I am SO impressed, I just
drove the A today, in SUPER heavy traffic, and it's just perfect (err 99%
perfect, see below). :)) Lawrie shows using one of these in his video that
Moss sells on Tuning SU's. If you buy one thing for you car, buy one of
these. I'm not kidding (no I don't own Gunson <G>).
Thanks to the Colortune, I've now found a slight problem with the MGA. It
has a *very* slight misfire, every say 5 secs or so, in #3 and #4. The
Colortune shows it up as a slight richening/leaning (don't know which - it
goes yellow) of the mixture. The dist. is set perfectly (Dwell at 50
degrees, new Bosch dist y'see), 12 degrees BTDC at 900rpm, tappets etc to
spec, new coil, new leads. I am guessing it's a fuel delivery issue. Could
it be a slightly glitchy fuel pump or a float height issue? Anyone? I'm
really just starting to nit pick here, but what the heck. :) I've never seen
such a good stable idle, virtually rock at 850rpm all the way through 1
1/2hrs of heavy traffic.
The other issue, how on earth is the Choke 'supposed' to work on an MGA? I
have never had the linkage that hooks the two carbs together, so the choke
only worked on one carb, and the fast idle didn't work at all! Well I fixed
all that on the weekend, but how is the choke supposed to *stay* out, the
cable appears to be under tension, and is quite difficult to pull. It'll
only stay out of a minute or so, and now the carbs are bang on, it really
needs some choke to start her and keep her going for the first 10mins or so.
Any suggestions here?