Car is a 1985 325e. Full story on my purchase and ongoing project is here. When I got it, it didn't run, but it did have spark. I verified this by spraying ether in the throttle body, which would make it cough and "run" for a few seconds. But it wasn't getting fuel, as detailed in this thread. After I fixed that issue, the "no spark" condition appeared. I DO have fuel pressure now, verified by pulling the fuel line under the hood and cranking. Here's what I've done to try and troubleshoot this issue.
- Removed a plug, put it on a grounded surface, had a helper crank it. No visible spark.
- Replaced cap, rotor, wires, and plugs with all new parts. The old ones were looking pretty worn, here's an example:
Here's all the new stuff, ready to go in:
Checked for battery voltage at the coil, it looks good:
Checked the coil resistance, primary is a bit high:
Secondary is a little high, too, but not as bad:
I'm a little suspicious of those resistance readings, as they jumped around quite a bit as I moved the contacts, and I'm using an el cheapo Harbor Freight multimeter. But those were the lowest values I saw.
Finally, I checked the resistance of the crank position sensor:
This is where it gets a bit confusing. The Bentley manual says that the sensor should be at 960 ohms, but the meter is showing it as an open circuit. So the CPS is dead, right? But the thing is, I'm still getting fuel.
So, I have a suspect coil and a suspect CPS. Based on this information, which one of these non-cheap items would you purchase first?
TIA.
- Removed a plug, put it on a grounded surface, had a helper crank it. No visible spark.
- Replaced cap, rotor, wires, and plugs with all new parts. The old ones were looking pretty worn, here's an example:
Here's all the new stuff, ready to go in:
Checked for battery voltage at the coil, it looks good:
Checked the coil resistance, primary is a bit high:
Secondary is a little high, too, but not as bad:
I'm a little suspicious of those resistance readings, as they jumped around quite a bit as I moved the contacts, and I'm using an el cheapo Harbor Freight multimeter. But those were the lowest values I saw.
Finally, I checked the resistance of the crank position sensor:
This is where it gets a bit confusing. The Bentley manual says that the sensor should be at 960 ohms, but the meter is showing it as an open circuit. So the CPS is dead, right? But the thing is, I'm still getting fuel.
So, I have a suspect coil and a suspect CPS. Based on this information, which one of these non-cheap items would you purchase first?
TIA.
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