Try a different set (new if possible) of spark plug wires and if that
doesn't help, a new or known to be good coil. Do you have the balast
resister hooked up right for that type coil?
If you have no suction on the front carb and the throttle shafts are
openning properly/linkage ok, I would do a compression test to check for
some type of mechanical failure. Next ,pull off the valve cover and confirm
that the valves are not suck or hanging up. Though it's a little messy, you
can run the engine like this for a short period. Shining your timing light
on the valves will help you see their motion, it helps if your timing light
has an adjustable advance feature. Something is preventing one or both of
the cylinders on that carb from breathing properly. Sound mechanical. The
cylinder should pull in the same amount of charge at a given rpm regarles of
whether or not that cylinder is firing.
Chris Reichle
----------
From: mgs-owner
To: mgs
Subject: Yes, I STILL need help!
Date: Sunday,March 10,1996 11:24PM
>>>
>>> More info follows. I have checked the timing and all is well. The car
>>> will now run OK at idle but if I give it any gas, it will begin to run
>>Well, here is what happened. My 72B which has always started (yes, even
>>in cold weather) at the first turn now has a problem. It all began when I
>>read on the net that someone was using Mystery Oil in the dashpots of
>>their carbs in the winter and it helped with the initial rough
>>acceleration. So since it sounded like a good idea to me, I poured some
>>in my carbs. Since it was a beautiful day (almost 80 here in February!) I
>>was headed out for a nice top down run and tried to start the car. All I
>>got was an engine that was barely running which seemed to be firing on
>>one or maybe two cylinders and would not respond to the throttle at all.
>>About 300 rpm at best. After much trying I gave up and decided that it
>>must of been the mystery oil which had been so thin it ran down into the
>>carbs and had fouled the engine. I opened the carbs and yes oil was in
>>the throats so I took off the dashpots and cleaned everything up and then
>>also replaced the plugs but to make a long story short, no improvement.
>>Does anyone have any idea what may of happened? I havent had a chance to
>>check the timing or take a look at the electronic ignition but if anyone
>>has any other ideas please let me know.
>>> very rough and stall. Lifting the piston on the front carb all the way
>>> seems to have little effect while the rear carb will kill the engine if
I
>>> do the same. If I put my had over the intake of the rear carb when
>>> running I get a lot of suction and the car will stall if I keep it there
>>> very long while on the front carb I get about 1/2 the suction (not a
>>> calibrated hand) and only a little change in the running. I have a crane
>>> electronic ignition and it SEEMS to be working OK. I guess my next step
>>> will be to pull the carbs (yuck) and do a complete check unless someone
>>> can give me a better idea.
Sorry this is getting so long but...it is still broke!. Here is the
latest. I noticed that when I was checking the timing that when I reved
up the engine (as much as possible) and it began to misfire, that the
flash of the timing light became erratic. I also noticed that the tach on
the dash dropped to almost 0 rpm when the misfiring began and then jumps
back to normal when I let of the gas and the engine smooths out. It
appears that when the rpm gets above about 2000, the spark becomes very
erratic and this is the cause of my problem. The question is why? I have
a carne/allison electronic ignition with stock (original) coil. I tried
this with the vacuum line off the distributor but no difference. The fact
that the tach drops (I have modified the tach to use the later version
which just connects to the distributor) would seem to indicate loss of
voltage here but I am not sure why. Also how does the lack of suction
from the front carb fit in to all of this? I have recently put new shafts
in the carbs and they are tight. I also pulled the float and jet from the
front carb and made sure everything was clean and in good shape but no
improvement. Any help would be VERY much appreciated. Thanks in advance.
Allan Hovis
hovisa@nando.net
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