> Ok lets keep this simple, take out number one spark plugs , turn the
> engine over until you feel compression coming up through the hole , at
> that point you should have top dead center coming up to the timimg
> mark, ( make sure the mark is sitting in ) degrees) .Re and re your
> dist shaft and housing making sure the rotor is pointing at number one
> high tension wire.then reset your ign timing with a timing light. If
> you think the timing chain/gears are worn or skip do a compression
> test on all eight cyls. should be within twenty percent of each
> other.Also another way to check the timing gears< Move the crank
> balancer back and forth while watching the rotor the balancer should
> move any more the four degree one way or the other before it moves the
> rotor. If you wannt to test the voltage to plugs: buy a ST125 DELCO
> NUMBER(about $10.00) at your local auto shop and that will test the
> secondary side of the ign system,needs 30,000 volts to fire the ST125.
> Not to be smart but as anyone check the fuel in the carb
> Frankandthebeans
If the chain and sprockets are worn, the engine can de-index itself by
one sprocket tooth. If this happens, "proper timing" as tested with a
timing light can only be achieved with the distributor rotated very far
out of a "normal" position corresponding roughly to the diagrams in the
Service Manual (#1 tower pointing in the general direction of #2
cylinder). The engine will run, but very poorly in terms of power and
smoothness. If the chain "skips" a total of more than one tooth, the
engine is unlikely to start.
I had this exact occurrence, with the former symptoms, on a '77 318
after about 100,000 miles of hauling a 3/4 ton van and, often, an
assortment of boat trailers about the countryside. Replacing the chain
and sprockets was a successful fix.
Failing a sooner and simpler explanation: Your original problem may be
a single sprocket tooth offset in the crank/cam timing gear, although
that seems less likely if the misfiring and backfiring were only
"occasional" as I believe you said. Try setting the timing using the
static method or the timing light and see how the distributer is
oriented. when finished. If it's way out, removing the timing chain
cover is called for. Or a trip to the computerized diagnostic clinic.
Either will expose any problem.
--
Regards,
Bill Combs
[EMAIL PROTECTED]
http://home.earthlink.net/~ttursine
--
History does not repeat
itself, but it does rhyme.
- Mark Twain
[Non-text portions of this message have been removed]
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