Hello Sunbeamers:
I just went through a full day+ messing about with the Tiger after it
suddenly started missing and sputtering last night. I finally did figure
out what the cause was after hours of trial and error today, and made
the fix easily once I found out what caused it. It turns out the problem
cause was pretty obvious, but I'm not one to do things the easy way. I
thought my "fun" may be of some help to other Tigers out there.
The sputtering and missing happend suddenly. The Tiger was running great
until I parked the car at a store. A few minutes later, when I started
it up again, it immediately ran like %$$$#!. I limped it home and
commenced looking for the problem. Since I had run totally out of gas a
couple of days earlier, my first suspicion was a plugged fuel filter
(I've got to get those tanks cleaned out one of these days). I have a
filter just before the fuel pump and another one in the stock position
just before the carb, The carb filter was clean but, sure enough, the
filter at the fuel pump had lots of black rubber bits in it. I replaced
both filters and started it up again. No go. It still ran badly. Next I
was suspicious that I had an ignition problem of some sort. I started
testing my plug wires and, sure enough, #7 and#8 wires had pretty high
resistance. Probably since when I originally assembled the wires the
first time I didn't do a good job. I cut off the old clips and put new
ones on the wires and resistanme went down to almost zero, solving the
problem, or so I thought. No luck again, it still ran badly. I pulled
off the wire from plug #8 and started the car without it connected. It
ran no better or worse so I figured it must be that spark plug. In went
a new one and........no difference. Was I happy with my work at that
point! (This is a sarcastic comment).
A lot of swearing and solemn oaths spewed forth from my general vicinity
at this point. Some of the more mild ones were to the effect of why
don't I get a real car someday (This is one of my favorite self
complaints when the Tiger is not runnng well), and who designed that
little access hole for plug #8?
Maybe the timing had slipped somehow? Checked that and it was OK. Maybe
the idle mix screws had backed out? They were fine. The carb did turn
out to be slightly loose, so I snugged it down. No change. The manifold
seemed plenty tight too. Running the car at idle, I listened around the
engine compartment with a hose to see if I could hear a vacuum leak
anywhere. No hissing sounds were found. I was just about ready tg give
up and call in outside paid help. Standing there staring at the engine
compartment and shaking my head at my frustration at not finding the
problem after all of that, I suddenly spotted the cause. A 10 cent
plastic vacuum tube plug had somehow worked its way off the carb. On
went a new one and the car again runs like brand new.
Is there a lesson in all of this? Beats me! But it sure feels a lot
better now that the Tiger is running well again.
Steve Sage
1967 MK1A
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