So where, exactly, is it? I don't have any jacks right now and am wondering if one will suffice, or if I need two or if ramps would just be better.

My issue is vacuum; I tested much of the system yesterday (Diesel Giant, you would be proud!) and discovered that when I plug the line leading from the blue plastic 'transducer' to the modulator, my vac. reading leading into the white vacuum valve on the IP goes from 5 hg to about 20 hg while the car is idling. With 5 hg there the system doesn't have enough vacuum to shut off with the key, so this is definitely a problem.

I assume I have a vacuum leak in the modulator itself or in the line leading to it. These CA cars have bearish vacuum systems, it would seem, so hopefully my problems will end if I fix this, but who knows.

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

Left side of the transmission. At the end of the vacuum line. There is a black rubber cap on the modulator which is essential to vacuum integrity. It coud be as simple as replacing the cap or the rubber connector at the modulator. Raise the left side of the car and slide under from just behind the left front tire.

I'm really hoping it's as simple as replacing the cap or line. Knowing my luck it won't be, of course.

Thank you for the info.

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

If the modulator is original, it's a safe bet that it could stand to be renewed. A simple job, complicated somewhat by access issues with the transmission in the car. If you decide to replace the modulator, I would suggest procuring a new pin (approx $3) at the same time, as it is very easy to break the original one when the old modulator is removed. (This assumes that you have the version with the plastic pin.)

Then, of course, you have to adjust the new modulator. And the procudure for that is subject to substantial debate. I went to the trouble of fabricating a gauge and setting the recommended pressure. The transmission shifted poorly at that pressure, so I adjusted by feel from that point.

My vacuum modulators are on the right side of the trannies [facing front of car] but that's not why I responded to this thread.

I know you are anxious to get to the task of solving your problem, but I strongly recommend that IF you jack up the car rather than driving it up on one or more very sturdy ramp support(s)... when jacking I recommend you always have at least two supports under the car before you go under yourself... and this usually means you jack it up, put a sturdy stand under it, and then you lower the jack but keep it supporting ~50% of the car's weight with the stand supporting the remainder. Then individually grab the jack and the stand and give each a good shake. And after that grab with both hands or put your foot on a bumper and shake to be certain the car is steady!
Best regards,
Sam... yes I'm " MrSafety2@Verizon.Net " !!

Sorry if I got that wrong. I remembered it being on the driver's side. But I am getting old, and they say the memory is the second thing to go.

And maybe one of the reasons that I am getting old is that I never get under a car supported by a jack.