1998 LS400 Coil Pack test

[Lexcelsior007]

I want to check the resistance of the coils in my 98 LS. I have taken them out and there are 4 prong connectors on them. I have a multimeter but want to know what resistance and prongs I should be measuring. Thanks in advance to your replies.

[Lexus_DK]

if you suspect a bad coil, try running the engine and unplugging the coil connector. Does the engine idle differently? You can also try swapping it with a different coil from another cylinder and see if you get a different misfire code.

[Lexcelsior007]

Thanks. I thought it would be better to test resistance since I already had them out. I will test using the unplugging method as well.

[Yamae]

You can test it only partially just measuring the resistance. The drive circuit is organized by semiconductors and the resistance varies depending on the measuring equipments since the applied voltage is not the same. Some shows 300 ohms and some other 500 ohms.

Lexus_DK's method is a good choice. Another simple and useful method is to use an air gap of a half inch instead of a spark plug. A good arcing energy can travel more than a half inch in ambient atmosphere.