I have a rather odd problem with my '95 540/6. Sometimes when I start it, especially when cold, it will crank and start as usual, idle for maybe a second, then die. I start it again, and it runs great. It idles up like it's supposed to when cold, then slows down as it warms up. Overall it runs well. I recently did the upstream oxygen sensors, cleaned the TB and ICV. No codes or CEL. DME temp sensor maybe? Any ideas?