Thanks for responding.
When the valve cover cap is removed each time one of the valves actuates
there is a distinct Psssft sound..
The stumble does go away under acceleration, but power seems down slightly.
The stumble is most noticeable under light acceleration and between shifts.
Feels a little like it's hitting on 5 for a second then back to 6.
Don't know how to check for positive or negatinve pressure in crankcase.
At 11:13 AM 10/3/96 -0400, you wrote:
>Lawrence Schilling wrote:
>>
>> Had a local shop do a tune-up on my '73 Stag with the '73 TR6 engine
>> yesterday. The mechanic said the valves were at about 50 so he adjusted
>> them to about 10. Does this sound correct??
>
>YES, if he did it properly.
>
>>
>> He also said there is a Pfssst sound coming from one of the valves which he
>> diagnosed as exhaust leaking past an exhaust valve that has some carbon
>> build up on it. Does this feasible??
>>
>
>NOPE. Is there a positive pressure in your crank case? That would be
>one way to verify it. TR6's are designed to have negative pressure in
>the crank case. Where is the noise coming from? Does it pulse? Carbon
>can build up but it shouldn't be holding your valve open! It would
>cause a dead cylinder if the valve was hung open.
>
>> There is a definite stumble in the rev range and seems a little down on
power.
>
>Is there a constant miss or do you notice it only at cruise speed? Does
>the stumble disappear when you accelerate?
>
>Regards,
>
>Chad
>
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