How does one adjust the fuel pressure regulator on a 1991 500SL ?

or is it not adjustable?

does anyone have any tips for a step by step procedure to install a new one?

thanks

 

No problem!

500SL was not running well and I completely replaced most all the electrical components (as that's where I always start because my 50 years working on various cars the problem has been electrical (not fuel) 80% of the time.
and that did not fix it.
So I decided to replace at the same time:
1. new accumulator
2. all 8 brand new injectors, including new seals, and plastic holders with new o-rings
3. new hydraulic actuator
4. new fuel regulator
5. re-manufactured cold start slide air valve

I couldn't find a new or even rebuilt fuel distributer and i couldn't find a new cold start fuel injector. (any tips on source of those?)

when the new fuel regulator arrived I couldn't see any adustment on it, but some people say it is adjustable, so I asked (just out of curiosity just in case I ever wanted to adjust the pressure) .

I asked for a step by step procedure on installing it because (at first glace) it looked like maybe some fuel lines would have to be completely removed--so I submitted this thread.

Before any replies, I went ahead yesterday and already installed it and it was far easier than it looked. (I only had to remove one line) . Only took like 15 minutes to replace it.

Also the hydraulic actuator looked like it would be hard to get out without removing either the 2 fuel lines, or the linkage, --- but it slid right out and only took me 2 minutes to get it out and another 2 minutes to install the new one. (4 minutes total)

The only problem I had was the original 30 year old rubber and plastic crankcase ventilation and idle air hoses to the 8 injectors were so hard and briitle they broke in pieces when I removed them, so I couldn't finish the job and had to order today all 16 new hose pieces at $200.

 

I do know where the two locations are to adjust the mixture, and which way to turn the screws.
? Can someone please tell me how to remove the ball bearing in order to adjust the mixture at idle?

but I never knew what you just told me. That's a wonderful thing to know! (thanks) The 500SL had the "feel " like it had been running lean with a hesitation on full acceleration (especially from a stop)
It also barely ran (missed like crazy) when start it cold (first 30 seconds ).

Does one need two meters be able to read both voltage at the same time?
Does one need a "duty cycle" meter?