Matysiak
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| posted on 24/2/09 at 06:57 AM |
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erratic rev counter
My rev counter is misbehaving on my crossflow. Works fine until 3000 rpm or so, then flies flies off the scale. Some times it's a little erratic
at idle bouncing around.
Another interesting point is my timing light doesn't want to flash until the revs are around 3000 rpm.
I have re run the ground cables to the rev counter, the coil is new, new plugs, distributor is only six months old - electronic, new alternator.
Any ideas?
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Matysiak
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| posted on 25/2/09 at 08:01 AM |
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ANyone any ideas for me to try?
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C10CoryM
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| posted on 25/2/09 at 03:00 PM |
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Does the car run ok?
Sounds like maybe your primary ignition signal (the one that collapses the coil and makes spark out of the secondary part of the coil. also what
tachometers and timing light read.) may be the problem.
The car would be running poorly though. Check the power/ground for the ign module,distributor or whatever your car uses. They can get screwed up if
they share circuits with other things that short out.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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Matysiak
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| posted on 25/2/09 at 04:54 PM |
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The car is running okay, but not great. Starts fine, revs okay but seems really lacking in power.
The car has an electronic Lucas distributor.
What part is responsible for the signal, the coil or the ignition module?
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C10CoryM
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| posted on 26/2/09 at 01:50 AM |
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Well, I am going to ASSume the lucas setup is similar to most others. My terminology may be different as well but here goes:
The primary ignition signal comes out of the ignition module, and goes to the negative side of the ignition coil. The primary signal is what controls
when the coil discharges. This signal is also what tells your tachometer how fast the engine is spinning.
Because this signal controls when the coil discharges, it must be "clean" and accurate. If it is dirty, you may get weak spark, or spark
at the incorrect time. If the signal shorts to ground through a defective tachometer (for example), the car will shut off. Also a V6 or V8 tach may
make a 4cyl run poorly.
If that didn't help clear up how things work try this:
Disconnect the wire of the tachometer that goes to the negative side of the coil. Then try your timing light again. If the timing light flashes as
it is supposed to, try driving the car and see how it feels.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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Matysiak
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| posted on 2/3/09 at 02:27 PM |
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I disconected the speedo from the coil and the timing light flashed perfectly at idle, but as soon as i revved the car, it stopped flashing. I on;t
revved the car slightly for the timing light to stop working.
Must be a wiring issue?
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MikeRJ
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| posted on 2/3/09 at 02:31 PM |
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What is the make/model of tachometer you are using?
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Matysiak
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| posted on 2/3/09 at 05:59 PM |
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Its an autogauge 85 mm. Was bought new with all the other gauges.
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C10CoryM
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| posted on 3/3/09 at 02:30 AM |
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The timing light should be picking up the secondary voltage on the wire. For it to stop flashing means that:
your car is not running 
the wire you are on has no spark going through it (try another wire)
or your timing light is dead
The only other thing would be that the secondary signal is so ugly the timing light can't pick it up accurately. Not very likely as the car
should die before that.
Try another cylinders wire and if not better try another timing light.
The aftermarket tachometer may have a way to set it for 4, 6 or 8 cylinder.... make sure yours is set right.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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C10CoryM
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| posted on 3/3/09 at 02:37 AM |
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Have a look here:
http://www.offroaders.com/tech/Autogage-Tachometer.htm
Looks like autoguage has their tachs set to 8cyl. That may be all your problem is.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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