>My Cal. Spec 76 1500 has a carb issue too. It doesn't want to start when
>cold. Choke appears to be correct but not certain. What can do to ensure
>all is set correctly? Runs fine once it does start.
>Peter S
>
Some Stromberg Carb Basics,
1 The piston (and hence needle) are controlled by the air flow through the
carb.
2 Any Air leaks will mess up the mixture.
3 As emissions got tighter, the carbs got more complex.
4 The choke allows the fuel to bypass the needle, by an orifice before the
bridge of the carb.
5 The float level also controls the mixture - especially during starting
So...
a Check the float level - Should be 18mm from the body of the carb to the
highest point with the
carb inverted (sorry, you have to remove it!) If it is too low, the
choke won't work right.
b Check that the choke plate is not put on 180 degrees out. (remove three
screws, the large hole
should be at the bottom of the disc) - DO NOT TAKE THE AUTOSTARTER
APART!
c Check the bypass valve - (remove and make sure the diaphragm isn't
damaged) Also check that
the piston inside will move under pressure (carefully press with
screwdriver)
d Since this is 76 Cal Spec, should have autochoke. These are very
reliable once set up, but
difficult to reset if messed with. Make sure that the heat mass markings
are centered on the mount.
Make sure that when cold, if you depress and release the throttle, that
the plunger will allow the
autostarter to rotate inside. When warmed, but not running, It should
allow the throttle to close completely.
If any of these are out, get a GOOD manual on the car, and follow the
instructions VERY carefully to
reset. Bently and OEM manuals have good descriptions - haynes is
useless. Otherwise, try an old Volvo
mechanic - they used them too!
e The Idle Air Control valve works with the autostarter to allow cold
starts to function correctly. If you
have the idle controlled by the throttle plate, it won't allow the
autostarter to open the throttle enough to
get a good cold start. Once warmed, even a little, it will start great.
NOTE - in the owners manual for Autostarter Models (75?-80 Cal Spec/76-80
Canadian/78-80 49 state)
it does indicate that to start the car from cold, you must depress and
release the throttle once before starting
to allow the autostarter to engage. This is the only carb used on the
Triumph range which requires this.
I had a 1980 Cal Spec using this carb and it ran flawlessly through 3 years
of daily driving (including a 50+ mile daily commute to work!) I'd still
have it, except that in south-western BC it rains too much in the winter,
and the
hard and soft top seals were difficult to keep effective at 65 MPH.
Please note that if the autostarter has been replaced with a manual choke,
the choke will need to be pulled out
less to richen the mixture less because of the idle air control valve. You
will need to adjust the fast idle to compensate for this (raise the fast
idle to ~1800 instead of ~1200)
Hope this helps...
Wayne Burton
1963 Triumph Spitfire4
1966 Triumph 2000
1954 Austin A40 Somerset
|