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Re: Hesitation on Acceleration

To: David McNaughton <>
Subject: Re: Hesitation on Acceleration
From: Skye Poier <>
Date: Fri, 10 Dec 1999 14:51:02 -0800
Go for a drive and get the car up to the temp where it starts acting
strangely.  Got on for a little while then shut off the engine and coast
to the side of the road in a safe spot.   Pull each plug and look
at the colour of the electrodes.

white:  too lean. mixture? fuel starvation? air leaks?
tan:    perfect
black:  too rich. mixture?

I can't remember, does the HIF carb have a lift pin?  You can quickly tell
if the carbs are set properly by raising the piston by 1/8", the rpm should
go up slightly and then drop back to normal.

Also, pull the fuel line and put it in a bottle and turn the ignition on
(obviously, dont try starting the car).  The fuel pump should pump about
a half litre of gas in 1 minute

There's lots of easy things to check.......

Not that tuning the carbs is difficult, and should probably be done 
anyway!  Might want to check/set the valve to rocker gap and the timing
while you're at it, too.

If you can't seem to get the carbs set right, you might have an air
leak.  Check the throttle shafts for slop, and try spraying carb cleaner
around the manifold and carbs while the car is running & hot and listen
for rpm drops to indicate the location of the leak.


Word on the street is that David McNaughton said:
> Again a cry for advice from the MG community!
> My 1973 MGBGT (1800) has recently been very hesitant on acceleration
> from tickover and needs to be "coaxed" with the accelerator.  It runs
> just fine when cold and with the choke pulled out!  I also notice that
> this evening the tickover has dropped way low and the car stalls.

1966 MGB - GHN3L     Safety Fast!             __,__\__ 
The MGB Experience   (_o____o_)

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