I need to adjust the iddle in the w124, I adjusted that tab with the numbers on it to 7 but I still feel like it iddles real soft and sometimes the motor will turn off while in iddle, I thought it was compression but now I don’t think so because of the car runs very powerful, I just had to replace a diesel fuel injection line,you don’t think I still got air in the system and that’s why it iddle so soft,or do you think its because there is some kind of electronic iddle adjustment,please help.

2.i just broke that hard plastic fuel line on a w123 that goes from the injection pump to the top of the fuel filter,it was brittle,now I cant drive care,2 questions,is it ok to drive it with a piece of regular fuel line?
or if and when I buy the actual part is it easy to stick it in,it looks dam tough and hard to insert,got any clues??