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Re: Distributor on 78MGB

To: dhobbs@arcom.com
Subject: Re: Distributor on 78MGB
From: fickes@taurus.apple.com (Stan Fickes)
Date: Wed, 9 Nov 1994 13:52:01 -0800
>Well, I really goofed this time.
>
>I puilled my plugs so I could turn the crankshaft to set the valve
>clearance.  When I put everything back together I car would not start.  I
>am sure I replaced the plug wires wrong.
>
>Can anyone give the the wiring layout for a 78MGB.  I know the firing
>order is 1-4-3-2, but I have not been able to fine the 1 positon.
>
>I would prefer to not find 1 by aligning the timing mark and pulling the
>distributor cap.  The car is in my garage and the light is not that good.
>
>Any help would be appreciated.
>
>Dan Hobbs

A simple way to find "close to TDC#1" is to pull the #1 plug, press your
thumb against the hole, crank the engine with the starter until your thumb
is blown off the hole.  This happens on the compression stroke for #1,
which should get you pretty nearly on to the rotor position for #1 TDC.  I
recommend doing this with all plugs out, so the engine won't back down due
to compression in another cylinder after you stop cranking.  If you want to
get closer than this, you'll need to either use the timing marks or make
sure the piston is at the top of its stroke by looking into the spark plug
hole.

I think you've got the firing order wrong.  Since 1 and 4 are on the same
direction stroke, they should be 1-X-4-X.  Similarly for 2 and 3.  I
believe the order (please someone, check this!) is 1-3-4-2.

For future reference, write the plug number on the plug end of each wire
with a permanent marker, and NEVER take all the wires off the distributor
at the same time.  Replace wires one at a time!!!!
sf

Stan Fickes                    British Cars
Wireless Communication Tech.   1951 MGTD (under restoration)
Advanced Technology Group      1965 Austin-Healey Sprite (daily driver)
Apple Computer, Inc.
408 974-7653





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