I have a 90 300e with 160,000 miles. Symptoms are as follows:
On first and every start of the day, the engine fires for a second then dies.
On second attempt, it starts and stays running with a little nudge of the throttle. It idles rough at first then smooths out.
During the first 5 minutes of driving, the engine surges somewhat around 2200 RPM.
When warm it has a very rough idle.
I let the car sit for a week one time and it started great.
I got the car from my sister a few months ago and it has always had a bad idle.
I am out of town for two weeks and a mechanic diagnosed as follows:
When trying to adjust the mixture, he said his meter was jumping all over the place and would not stabilize which would necessitate replacement of the air flow meter at a cost of $1100.
My wife picked the car up and she said she barely made it home.
I am not second guessing him but I am not in a financial condition to cough up this kind of money. I have been an aircraft mechanic for 20 years and can remove and install just about any part but am not sure if I should tackle this myself due to the adjustments that would be required.
The plugs(copper), fuel filter, EHA valve, O2 sensor and EGR valve have been replaced. Some wiring for the O2 sensor has been replaced as well.
I will appreciate any replies.