>Rich Mason (that's me) wrote:
Following float replacement in both HIF-4's...
>> The present symptom is a 500 rpm swing in rpm, no matter where the throttle
>> is set, and more noticeable when it warms up. If I hold the pedal for 1500
>> rpm - it will drop to 1000 rpm for a second or two, then climb back up to
>> 1500 for a few seconds, then fall back down to 1000 again. If I set the
>> idle at 1000 rpm - it drops to 500 and stalls out.
I wanted to thank all the respondents too many to send this reply to all of
them... The ideas got me to thinking more and looking more closely at a few
things. It appears that the quality control on the floats was the culprit.
The new floats (for the HIF-4's) had molding flash near the pivot pin. I
caught this when I received the parts and thought I trimmed them
sufficiently. The front float was still a tight fit - so I opted to remove
one of the two washers.
Upon disassembly - both floats appeared to be binding (I don't recall them
being tight when I assembled them - maybe some swelling?) I sanded about
0.040" off the straight end and cleaned it well. Everything went back
together per spec (including the use of both washers as before), and the car
is running exceptionally well again.
Lessons learned - 1) new parts aren't always as good as the old parts
(although the new floats are floating) 2) if it doesn't look right - it
probably isn't, and 3) the nicer the weather - the longer it will take to
find the problem and fix it.
Thanks again for all the helpful advice!
Regards,
Rich Mason
'73 MGB
Madison, AL
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e-mail--> rmason@ro.com
MG Page-> http://ro.com/~rmason/mgpage.htm
NABMS --> http://www.geocities.com/MotorCity/Garage/5207/
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