cadeques

I have searched this forum and others unsuccessfully trying to see if someone knows or can share how to test a coil on a GS 400?

I have a basic multimeter and have tested a number of coils on other cars and motorcycles and understand the basics however these coils have 4 prongs and I cannot get a reading regardless of where I test it at.

Do I have to take the boot off in order to get an accurate reading?

Any help would be appreciated.

GS4_Fiend

iTrader: (22)

To this the coil, you would need to buy one of those adjustable spark tester, thexton got those on amazon. If the coil can produce at least 30 KV, coil is good. Although its not accurate compared to having an ignition scope but it gives u an idea.

CleanSC

The method to test the coil on plug on the V8 is as follows:

1. Remove coil.
2. Remove plug.
3. Install plug into coil.
4. Plug in coil.
5. Unplug all 8 injectors.
6. Ground plug against engine and crank.

If you see spark on the plug, it's good.

If no spark, try another coil. If that one sparks, dead coil. If it doesn't, you have a control issue upstream of the coil.

Now, if you are getting misfires and believe it's a bad coil, swap the coil to another cylinder and see if the misfire follows it. If it does, your coil is bad. If not, look elsewhere like spark plugs, compression, injectors, etc.

cadeques

Thanks CleanSC

I will give your method a try as it makes sense after I thought about it. I was stuck on trying to test the coil from an ohms persective not from whether or not I was getting spark.

I will test and share results.

CleanSC

Remember these coils have the igniter built into them, so bench testing with a meter won't tell you much of anything. The best way is to test it live, working in the car.