Need help! - Cold Start Issue

[schneidercom]

I have a 1987 635csi that has developed a cold start problem. When the engine is cold, the motor cranks continuously but never fires. I am only able to start it by spraying ether into the air intake. Once the motor starts and warms up its fine.

I think I've exhausted all my troubleshooting steps, here is what I have done.

- Replaced the fuel with fresh gas.
- Ignition Tune-up (Cap, rotor, plugs)
- Replaced the cold start valve
- Replaced the ECU

Can anyone shed light on what else this could be?

Thanks!

[jsland]

Sounds like the spark is good based on your description so concentrate on fuel delivery. Troubleshoot and test the function of the new cold start valve. My car/engine is a good bit older so no direct knowledge of the details on your cold start valve but it would seem likely there is a sensor or harness issue and some circuit in parallel that takes over once a temperature limit is passed and allows the problem circuit to be bypassed.