my 1988 911 will only start now and than,if it fires?,it will stay running than after the key is turned off it won't fire back up, after it sits a day or two it will fire back up? what is the deal? thank you if you can help, I would love to drive her,the weather on the coast is great now!

 

Could be a couple things, but I would start by replacing the DME relay first. If that doesn't fix it, then I would look at the reference sensors and the cylinder head temp sensor.

 

I have done all of that,now what?

 

Have you checked the basics like spark, coil, plugs, distributer cap etc?