Hi all,I have an 1989 audi 500 and it wont start,I have checked spark,battery and fuel all checked out good.The thing is the engine turns over theres spark,power and fuel but it will only start sometime and not often but when you push start it it starts every time.Do you have any idea's?

 

I would suspect the cold start valve is not being actuated. It acts like a choke when the engine is cold.

 

Any idea's how I can test if its the cold start valve ?

 

Yes, but I do not have the time right now to go over it.

 

The cold start valve sprays fuel into the intake manifold when the engine temp is below 86 degrees while starting. The duration of the spray is from none to 12 seconds determined by a temp sender. The quick check would be to ground the high tension wire off the distributor. Then unplug the connector at the cold start valve and probe the connection. While someone is cranking the engine, see if voltage is being applied. If it is, then remove the valve, keeping the fuel line attached and reconnect the connector. Hold the working end over a cup and do the start cycle again, watching to see if there is an even cone of fuel spraying. Try this and then post the result.

 

Thank you very much I will check as soon as I can and get back to you.