Hi folks.
The TR6 is running flawlessly... it's my 'LJC' that needs a little help...
This is an older (1981) Toyota Corona with a 22R carburetted engine.
Bone stock, although I replaced it with a rebuilt unit in 1987. This
new engine has only got 25,000 on it, but the rest of the car is
pushing 225,000. (and that means all the ancillary engine
components: distributor, carburettor, etc.) This car has some sort
of electronic ignition, so points are not an issue. Inside the cap
there's a little "magnetic pickup" unit similar, I suppose, in
function to the Allison 'optical' unit on the TR.
Here's what's going on: First of all, it seems to misbehave mainly
in the TRANSITION between running 'cold' and achieving proper
operating temp. Of course, this time of year that transition is not
very long. When it is thoroughly warmed up, the incidence goes way
down.
When you're launching from a stop, or even very low speeds (like in a
parking lot) the engine stumbles instantaneously and nearly dies.
The stumble occurs JUST AFTER your left foot has LEFT the clutch
pedal and the engine is at low revs, just beginning (and I MEAN 'just
beginning') it's acceleration. It acts like maybe it's out of fuel,
if only for just an INSTANT (and I MEAN 'instant'). But then, just
as quickly as it tried to die, everything returns to normal and I
drive off. The net effect is a hurky-jerky start from a stop in 1st
gear. It can also happen in 2nd if revs are low enough and the load
is high enough. My usual immediate reaction is to throw the clutch
out again to keep the motor running, but I'm not sure that's always
necessary. Although, my wife says it's died on her a few times. You
can also minimize the stumbling by feathering the clutch a little and
giving it a bit more throttle. I think it's important to note that
when it stumbles, your left foot is COMPLETELY OFF of the clutch
pedal and has been even if only for a fraction of a second. The
engine begins accelerating normally, just long enough for you to
conclude that 'this time it's not going to do it' and just then, WHAM.
I didn't want to spend too much time troubleshooting this until I did
some basic maintenance over the weekend. It was LONG overdue for new
plugs, new cap and rotor, fuel filter and air cleaner. I also
changed plug wires. The cap and rotor were particularly shot. I was
hoping that by some fluke one of these things would eliminate the
problem, but I wasn't too surprised to find that it didn't make any
difference. At least I've eliminated those things and I can focus on
something else... But what? I'm leaning toward carburetion myself.
Mostly because I think asking a carburettor to travel 225000 miles
without a rebuild is a little unfair. At the same time, I HATE
working on these Hitachi down-draft type carbs. They are a pain.
I'd like nothing more than to be able to fit a trusty pair of
Zenith-Strombergs on it!! (he, he!)
Anyone have any suggestions?
Pete Chadwell
1981 Toyota Corona LE
1973 Triumph TR6
|