Ian,
My 75 had the same symptoms, and just as I was about to start checking
the temp sensors on the carb I notice hot gasses escaping around the
exhaust manifold. One of those DPOs removed the air pump and related
emissions stuff and just screwed something into the ends of the now
unused air inlets. I went out and bought some muffler weld and stopped
all the bleeding and I've never had the problem again. Not exactly sure
what it fixed but it was a lot easier to check and then fix than all the
other stuff I tried and has been suggested.
Check it out.
Robert
esteemed Listers:
What causes a '76 TR6 to stumble while accelerating after warming up?
Here's the scenario:
* Car starts easily and warms to operating temperature normally (temp
gauge works fine).
* For the first 15 minutes or so, it runs almost perfectly (only very
occasionally do I feel a slight misfire as I accelerate)
* After about 15 minutes, or if I shut the car off and restart it, the
engine is considerably rougher, missing as I engage the clutch at lower
rpms. Even in the upper gears, if there is any load on the engine
(accelerating up hills, etc), it stumbles much more noticeably than it
did
after just warming up. Accelerating through higher rpms, the problem
seems
to go away, but the next time I accelerate from a red light, it stumbles
again.
* Bottom line: the problem is almost unnoticeable for the first 15
minutes or so after warming up regardless of rpms or engine loading.
It's
very noticeable after that at lower rpms under load.
The engine is original with a legitimate 53,000 miles on it.
Compression is
about 115 to 125. It has new plugs, condenser, points, plug wires and
sport
coil. Valve guides leak a bit and the carbs leak dashpot oil (through
what
I assume are bad O-rings). Timing and valve adj are per spec, but I
opened
the plug gap to about .30 to take advantage of the sport coil
Anybody experience this before?
Thanks.
Ian
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