Last month I felt it was time to do a little work on my brides 89 740. It had been blowing FP relays (every 6 months) so time to find the problem. Also strange starting with rough cold idle. So I replaced the FP with a new Bosch along with the filter. I replaced the molded air intake hose with a new one and decided to clean the MAF sensor (1st time in 373K) using MAF cleaner (CRC). Also cleaned the throttle body which I usually do every 50K miles. Then cleaned and checked the IAC valve. Also just because the FPR was original I replaced it also. So the interesting thing is how it starts now. It starts at a quick turn of the key but cold idle is just under 1000 rpm and it is dead smooth. Before cleaning the MAF it would do a lumpy cold idle at about 1200 rpm. Now takes less then 10-15 seconds and it drops to 850 rpm and is dead smooth. Driveability is instant without any stumbling. Hot starts are just as quick and goes to 850 rpm . AC on idle stays at 850 after initial drag start . So what I never did or considered was to clean the MAF which I think contributed to the idle quality. Just an observation.

 

Funny how something that's simple and doesn't seem obvious can have such a dramatic effect. Congrats!