>>> "TS Internet Machine" <econ.tech.dti@gtnet.gov.uk> 06/23/97 10:36am
>>>
It will tickover at 800 rpm quite happily but the instant you hit the
gas
pedal the car starts to cough and splutter, backfires in the carbs and
spurts black smoke out of the back.... It will not rev over 2,500 rpm
and
runs really really rough if you try and take it over its tickover.
We've changed the fuel filter, checked the fuel delivery (sort of
sloshes
out at a leisurly pace at the carbs) and even tried running the car
without
a filter but no change to the situation. One point of note is that the
plugs are really black when it's been running for a while.
>>>>>>
Sounds to me like there's a timing problem. Most cars will run nicely
at tickover with a badly retarded timing (in fact, this is purposely
done for emissions control on newer cars), but not at higher speed. Is
it possible you have a combination of retarded timing, and broken
advance mechanisms?
I'd check the dwell (or point gap) first, then see about the timing.
I've read on this list that the crankshaft pulleys sometimes start to
come apart, so the timing marks may be out of whack. Pull the plugs and
watch the #1 piston rise as compared to the timing marks. (I've seen a
very inexpensive tool which is basically a whistle on a spark plug
thread. As the piston comes up, it blows air through the whistle. At
TDC, it ceases.) Then get out your timing light and double check your
settings. Once you've got idle timing set, see if the timing advances
as the engine is revved (mechanical advance) and as the vacuum increases
(vacuum advance).
Safety Faust,
Matt Kulka
'74 B - running at about 18 BTDC @ 1500 rpm until the next smog check.
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