On Mon, 26 Feb 1996, Tim Moses wrote:
> After months of tinkering with and rebuilding the carbureator, I got
> my '79 MGB (single Zentih carb) RUNNING !!!! Took it out for a spin !!!
> The fire is still alive!!!
>
Indeed, it is.
> The car is very, very, very hard to start. It is reluctant to
> fire and takes about 15-20 seconds of continuous cranking to begin to fire.
Hmmmmn. It should catch on the first or second crank. Sounds like
some sort of fuel starvation. Are you sure you have adequate fuel
flow/pressure. My experience is limited to things SU, so I cant
comment on the tuning of ZS carbs.
> When it finally did start, the engine blew/burned a fair amount of
> oil producing white smoke. After about five (5) miles, the white smoke
> stopped altogether.
Oil smoke is *blue*, white smoke would indicate burning coolant to me.
Have you done a compression test recently? If the smoke is indeed white,
possibilities include a blown head gasket or a cracked head. Take a
peek ( peek, NOT leak! ) in the radiator. Does the water level need
to be topped off frequently? Do you see any traces of oil or foamy crud?
This means that oil is getting into the water jacket. Put your hand
behind the tailpipe, does the exhaust gas condense on your hand?
If the smoke is really blue, it could be several things: if the car has
been sitting for a while between starts, oil might be leaking down the
valve stems into the combustion chamber where it gets burnt off after
the car is started. If it smokes ALL the time, worn rings are more
likely the culprit.
> Can anyone tell me what I need to do??? Where do I go from here??
> Why is it so hard to start?? Is it the timing?? the ignition?? WHy does it
> smoke so?? Is it running too rich??
First things first. If you dont have them already, beg, borrow or
steal a compression tester, a feeler gauge, and a shop manual. Set
the valve clearance and do a compression test. Verify that each
cylinder has good compression and that the highest reading is within,
say, 10% of the lowest. Assuming the readings are ok, next, set the
points gap and inspect the distributor cap for cracks, pits, etc,
replacing if necessary.
Now, try to start the car. If it runs, great, take it for a spin,
shut it off and yank the plugs. They should be browish- (the front
of any Haynes manual has a good guide for deciphering spark plug
appearance, BTW). You can now play with the carb and be confident
that the changes are worth the effort.
If it doesnt run, reset the carb again according to the procedure you
did originally. It should run, if it doesn't check for air leaks and
make sure the dreaded pollotion control stuff (if present) is hooked
up and functioning.
Good luck and keep us posted, but most of all dont give up.
--Scott
Scott Hower --> howersl@ttown.apci.com
Air Products & Chemicals, Inc.
7201 Hamilton Blvd Trexlertown, PA
(610) 481-2646 --A. Einstein
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