924Board.org

[Brian L.]

After testing for weak spark (white not blue) and eliminating other possibilities through the trouble shooting guide here: http://www.924board.org/posting.php?mode=newtopic&f=1
(page 200). I found my coil fail the primary resistance test, it meas. 4.45 Ohms. Per spec. it should be 1.0 - 1.35. The problem is nobody has this coil locally.
My question is will this aftermarket coil work? http://shop.accel-ignition.com/ignition-electrical-and-wiring/ignition-coils/chrome-super-stock-coil-points.html
Its at a auto parts store 2 miles from my house and the specs. say 1.4 Ohms primary resistance.

Oh yes and for you search first advocates the closest I could find was this: http://www.924board.org/viewtopic.php?t=18701&highlight=ignition+coil+replacement
although it is about a 1977 and they have the external ballast resister.

Funny thing is the coil here at Advance Auto says it has a primary resistance of .68 Ohms.
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1980 924 N.A. Monaco Blue owned since 1987
"Remember, sitting on your ass won't finish your project" -Puddins fab shop.

[Brian L.]

After picking up a replacement coil I checked it with my Ohm meter(Radio Shack) and found it didn't measure out any better than my old one. Then I pull out my old Simpson model 260 and found my Radio Shack meter is giving bogus readings. I just knew it wasn't going to be that easy.
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1980 924 N.A. Monaco Blue owned since 1987
"Remember, sitting on your ass won't finish your project" -Puddins fab shop.

[musicalannette]

it can be asking quite a lot of a dvm to read 1or 3 ohm accurately when its max on that range is say 200 or 500 ohms.

it will have the same problem, with really big resistances.

check it has a good battery in it. that can effect it.

most coils have similar primary and secondary windings.

as it is a BOSCHE distributor, a bosche electronic spark module i would think a bocshe coil (maroon in colour at top) from a european car will do.

if you start having a lot of cylinders then that can make the coil work twice as hard or even more and then make it hot, which, if it does not have enough oil cooling can cause problems.especially at high revs.

but as the 924 is a 4 cyl i would think most coils will work fine.

to accurately measure your resistance yo might need to use something called a wheatstone bridge.

wiki it it should be straigtforward.

good luck
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....