300E hard starting at warm ambiant temperature

[dacia]

Gentlemen, my '86 300E developed this nasty habit of hard starting when the outside temperature is above about 50 Fahrenheit. It cranks for about 10 seconds before firing up and then runs as usual, perfect. If the weather is cold it starts right away. If I depress the accelerator during cranking it makes starting even worse. The fuel mixture is a little rich
(I adjusted it for better acceleration, the car has about 250k miles on it, burns about 2 quarts of oil per 3000 miles). Any help would be appreciated, thanks

Alex