Help please. ( Ignition system questions)

[e30 gangsta]

Alright guys I am having an intermittent misfire issue. Sometimes the bike will run fine for 30 min, other times it might run ok for 3 min then just die out of nowhere. So I pulled out the fsm and started checking what I could with the limited time I had tonight.

First I checked the resistance of the pickup coils at the 4 prong tci connector. I placed the leads in the connector, and pushed on the plastic magnets on the vacuum advance to make it turn counter clockwise. Highest reading I got was 790Ω.

FSM states it should be 720Ω + or - 20%.

So 790Ω I believe is in spec.




Then I went to check the secondary resistance of the coils, I set the multi meter to 200kΩ.

Fsm states it should be 15kΩ + or - 20%.

First I checked the 1 & 4 cables and got 33.800 -5k caps = 28800
Then I checked 2&3 cables and I got 24.600 - 5k caps = 19600

I should note that this is with the coils still connected to their normal power source, still installed on the bike. Just with the key in the off position.

I am new to measuring resistance and I wanted to know if you guys thought these numbers looked correct?

One of the doubts I have is if I am supposed to perform this test with the coils disconnected? Or it doesn't matter because the key is in the off position?

Any help would be greatly appreciated.

[Radioguylogs]

All the reading are reasonable. I don't think you found a smoking gun yet.

The wires to the pick-up coils are are a common cause of your type of problem. They break inside the insulation and make intermittent contact. I've had it happen twice.

Could you read the resistance again while pulling on each of the 4 wires?

As you pull on the wires, you typically see the insulation neck down like an hourglass in the area of a breakage.

[cajun31]

ditto

check the pickup wires.