I have a bizarre situation that so far I am anable to remedy.
These are AUD404 SU's used with the air injection system ('71). The air
injections is removed system and the nainfild vacuum ports are capped, The
air tubes in the sides of the carb body are connected together rather than
being capped. There are no fuel leaks and I haven't been able to detect
excessive shaft wear or vacuum leaks anywhere. The jet nuts are down 12
flats and the butterflies are identically matched/sync'd
At first the car started easy and idled fine, but would miss when the
RPM's were increased. I discovered that the front carb had a shorter jet
(by more than 1/8") so it did not reach the bridge even with the adjuster
nut fully home. So I replaced it with a correct length jet. I thought sure
that would cure the problem. Now the miss is gone (for the most part), but
it won't idle correctly. It will rev up a bit then drop RPM to the pint
that it will almost die, then rev up again. I attribute this to the uneven
float levels. The rear has fuel right up to the bridge but the front one is
about 3/16" to 1/4" below the bridge. I don't really understand why, as the
level in the float seems higher. I tried a different float needle, but it
made no difference. Drawing the jets down seems to raise it slightly but it
won't come to the top like the rear one. I'm going to try a differnet float
lid today, but I can't think of anything else short of changi8ng the carbs
(which I donlt want to do) if that doesn't work.
Anyone have any ideas?
Gerard
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