I'm told I need a fuel pressure regulator for my 1983 380 sec. It has a high idle and lacks power, it does not want to go when accelerated.

Where is the fuel pressure regulator and how difficult is it to replace? I'm told the part cost 219.00 from napa is that fair.

My 1990 300e has a very low idle and wants to die at stops, also it takes a couple of cranks to start. I've changed the fuel filter and cleaned the throttle body any other suggestions.

Thanks!!!!!!!!!!