So after getting my timing situation down I am still diagnosing a slight misfire (or what seems to be a misfire). Distributor checked out good and secondary ignition coil checked good. I checked the primary ignition coil at both hot and cold and got .7 ohms. Tolerance for cold is .36-.55 ohms and hot is .45-.65 ohms. Just wanted to check and see what everyone else was seeing as a bad ignition coil when checking resistance. 0.15 seems like a small # to be off by but then again there is only a .19 window for the coil to check good. I'm using a Fluke 77 multimeter to check it and it should be spot-on as far as accuracy is concerned. What's your thoughts? (94 toyota 3VZE)

Thanks
Marty

 

The Fluke-77 is a good meter, and is likely accurate, but it doesn't have 4-wire ohms capability. Without that, you can't measure those low resistances accurately. The extra .15 ohms is lead and contact resistance, and you're lucky you got that close. Short the two meter leads together and see what you read.

I would say your coil is just fine based on those measurements.

 

Cool, Thanks! I was wondering about that... And thought .15 was quite a small error. I was going to swing by a parts store and see what a brand new one in the box read this weekend sometime but I'd say you're right.