[6pack] engine surge

[dave n]

thatbs the best way to describe it b the engine will surge on and off just
100 rpm or so, mostly at 3500+ rpm, except it seems to idle at a lower rpm and
more roughly than usual.

and its inconsistent.  drove probably 60+ miles no issue at all.  but on the
return trip had this issue.  thought it was bad gas so stopped and added maybe
1/3 tank plus two bottles of injector cleaner.

Ibm still thinking it might be bad gas, but Ibm also thinking of replacing
the spark plugs and maybe the fuel pump.

car is a 72 TR6, no emission equipment, triple carbs, mild cam, etc., running
close to 11 to 1 compression.  it  has been running well, although I have seen
this issue once or twice in the past few months, but just for a minute here
and there.