89 300 e runs fine for a minute or two
 

when cold the car starts just like it should. run it for a couple of minutes and it begins to run really ruff. missing and sputtering and will not take throttle. then it stalls and will not start. my thought. and trust me i am just guessing. the cold start enrichment circuit is 'sticking'. meaning that the 'choke' is sticking and the thing is running too rich once it approaches operating temperature. is there a way i can disable the cold start enrichment circuit once i have the bugger started and running smoothly? if this cures the problem then i have a clue as how to proceed. thank you. oh, plugs are brand new. ignition wires appear to be fine. no engine light on. am i correct in discounting a faulty o2 sensor? this 'ain't' my car. and would love to get it out of my drive way and back to where it belongs.

The enrichment is goverened by the engine coolant temperature sensor. No way it can stick. If it's broke, it stays at full cold mixture, ie rich. If the O2 sensor is broke, it just stays in "open loop" mode.

The best thing to do would be get a meter that can read duty cycle as well as the usual volts & ohms ($30 at Sears). Search for the post on "adjusting the EHA". Lots of good info contributed by several people.

thank you, sir.