560SEL hard start/no start condition.
 

I know this subject topic is beat to death but I may have a different situation:

I have just come into a situation with my 87' 560SEL where I try to start it initially and nothing happens except cranking. (My friend actually is trying to sort it out for me back home). Sometimes it does stumble and start but dies quickly. I then spray starting fluid into the air cleaner housing and alas' she fires and runs on her own then stumbles and dies. I restart it and give her gas and it keeps running. After about 2 mins she runs on her own and has seriously strong power. She usually starts again after turning her off but sometimes she doesn't and again I have to spray... but then start and runs normally without the stumble... I just want to know where I should shoot for. I have checked the vacuum lines and elbows and they look fine. I am going to clean the IAC valve tommorow....

TIA,
Chris