chromecat

how do you check a pickup coil.... my buddy thought you checked for ac voltage.... did that i read nothing... no fire... have msd coil puts out a spark with turning the key on and turning the key off but not when engine is turning over...

checked the other engine ( that runs) pickup coil when turning over and it didn't read either.... how do you check these things...

Thanks
Don

GOODT

easiest way is with a test light put aligator clip on battery + and put probe on - of coil crank mtr if light flashes pick up is ok

chromecat

thanks.. will check ...

is this likely my trouble... no spark when turning over... i have an msd installed no book for it though.

Don

Dave_N

If you have an MSD box, the above trick using the test light will not work. Bypass the MSD box and see if it runs. Also, check the pickup coil connections at the ignition module. They can get rusty and break off.

Dave

chromecat

that looks very nice...
i think mine kinda looks close to that condition.... i ordered a new pair...

Don

chromecat

i should still be able to unplug both leads and hook a ohm meter up and see if it bounce the needle though shouldn't I.

Don

Ted G

iTrader: (1)

ohms will not change as it spins, but voltage will in small amounts. However if it is dead it will probably read 0 ohms anyhow.

Airpacker

The best way is with a digital storage oscilloscope. A good digital volt meter set on ac volts will also work. Coil disconnected form harness, meter hooked to both leads from coil. The coil will produce a ac signal when excited by the reluctor( the spinning part) if it is functioning BUT even this test is not conclusive as the coil could be shorted internally producing a lower voltage output ( amplitude ) than necessary to trigger the ignition box.

Checking for coil winding resistance is also only a partial test unless you have the actual specification and then it will only tell you if you have a shorted ( 0 ohms ) or an open circuit ( infinite ). Having a second engine right there makes for some easy comparison testing though.

KNOT-RIGHT

I just went through this last weekend.

Unplug the pickup on the distributer.
Unplug the coil wire at distibuter and place it near
something metal.
With Ignition on short the two wires which go to the MSD box.
You should see a huge spark evrytime you short the wires going to the MSD box.
This indicates the MSD Box is working correctly.

The pick up in the MSD Distributer is a coil in itself
should read .04 to.08 ohms.
It is a hall effect setup which is a inductive wheel that
passes by the pickup simulating the above test..

Usualy whem the pickup is bad it reads wide open on a ohm meter.

Hope this helps.

Oh yeah 90 percent of most problems are bad connections.


Good luck
Gerry