| With
the winter setting-in across most parts of the Country and Pre/EU-I kind
of M800s and other Carburetted/Mechanical Distributor Type Cars out-numbering
others on the Roads even as of today, I feel it's time to draw Car Owners’
attention to the topic under discussion.
Most
Car Owners experience that when they start the car in the morning or after
it has been shut down for 5-6 hours, it feels very sluggish. Engaging
the car in 1st gear and upon even slowly stepping on the gas pedal, the
car does not ‘speed up’ at all. This goes on for ‘quite
some time’ and one has to drive at 10-12 kmph during this time.
Only after the Temp. Gauge needle touches ‘C’ and goes beyond,
the car becomes normal. All this inspite of the Engine Tune being in good
order – including the ‘CO’ Test.
The answer to this is that a ‘cold’ Engine is inherently sluggish,
to prevent it from spewing out excessive pollutants beyond the prescribed
norms during its warm-up period.
To overcome this difficulty, a device called 'Radiator Thermo-Valve' is
incorporated in the Cooling System, along with a 'by-Pass' circuit, with
the sole purpose of enabling the Engine to reach it's designed operating
temp.( 90* +/- 5*C) within a very short time.
Unfortunately, in a vast majority of cases, Owners/Mechanics/Authorised
Service Centres included, continue to think out of the Amby/Fiat Era that
this ‘Th-V’ is like a human appendix and has no useful purpose
- other than ‘heating up’ the engine !
Nothing could be farther than truth. To check whether this ‘Th-V’
is in place and in working order, here's what you can do :-
"First thing in the morning, BEFORE starting the engine after the
overnight shut down, take off the Radiator Cap, keep the Bonnet open and
then start the engine. Take a notch or so of the ‘Choke’ to
keep it from stalling.
"As soon as the Engine fires, go across to have a look into the now
open radiator neck. If you see turbulence/coolant circulation already,
then your ‘Th-V’ is either not there (removed like an Appendix)
or faulty (stuck in open position). If so, get it replaced at your A/S/C.
While its being installed, as an abundant precaution, ask them to check
out the ‘By-Pass’ ckt. as well, to ensure it's not blocked
with sediments due to lack of use. If this is not done, then with the
new Th-V in place, the engine will throw-up Coolant right upto the windscreen
when it warms up !
On the other hand, if the Th-V is in place and not faulty, you will see
no circulation in the open radiator neck for quite some time. Then as
the engine warms up, you would be able to see it setting-in ‘fits
and starts’, including tendency to overflow from the neck. Just
before that happens, shut-off the engine and replace the Radiator Cap
properly".
If the ‘Th-V’ is in place and working, the problem is somewhere
else !
The most common possibilities are -
a) The 'Accelerator-Pump-Jet' System of your Carb is either not working
or mal-adjusted,
b) The Vacuum Advance System of your Distributor is faulty,
c) A 'Retarded' Ign.Timing and
d) Your A/F mixture is set too lean (should be CO @ 0.5-1.0% for EU-I
and 1.0-2.5% for pre EU-I Cars).
Again it's a common misconception that setting it ‘leanest’
possible gives you max mileage. On the otherhand, it results more in stalling
when the Engine is cold.
If inspite of every thing being in place, a cold engine still has a tendency
to stall - depending on Ambient Temps - then as the Owner's Manual suggests
- take a ‘notch’ or two of the choke for the first few minutes.
This will not only prevent its ‘stalling’ but also help it
to warm up faster. However, please ensure that you don't forget to ‘reset’
it. If you do, you will not only be wasting fuel but also seriously cutting
into the lubrication ‘film’ on the cylinder walls/engine life
as well.
Content
generated by S. K. Gupta. - 10/’02. |