Hello all,

I am not having any luck with the vacuum source on my 87 300d. I have rotated it and since it was almost there anyway not a big improvement.

I want to have my vacuum supply going to the trans modulator to be 17 or so inches of vacuum. I am currently at 15. The initial cold shift does get it up to 17 and I might bypass the sensor if I can not find a way to increase the vacuum from the IP.

Can I remove and adjust the proportioning valve that is on the IP

Has anyone done this before.

Or do I adjust the blue vacuum amp (I heard that was possible) The IP sounds like a better option but I am open to suggestions.

Thanks


bob c

You can adjust the vac amplifier, but I didn't.

Turned out my harsh shift problem was bad vac transducers for the air recirc valve and the EGR valve. I plugged the supply lines for them and got proper vac to the tranny.

The proportioning valve on the IP is adjustable -- the attaching bolts are in slots so you can rotate it. It may also be worn out.

Also, check the restrictors in the vac lines for dirt -- if you have too much restriction, you won't get proper vac at the tranny. I've been told the main restrictor in the supply (under the 5-way T) sometimes has to be removed to get proper tranny vac.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter,

Thanks for a late night reply.

I did change out all the plastic hoses and rubber connectors. I did clean out all the Connectors for dirt and such. I did remove and replace the tubing for the arc valve and egr.

I did rotate the proportioning valve to its maximum.

I do not have any leaks and only need more vacuum from the IP pump to the vac amp. I believe the signal to the amp is 6 inches from the proportional valve. Out to the trans is 15 or so. Would it be a good idea to take the valve off the IP and take a look at it.

I hope that that is not worn out too. It seems to work fine just not enough vacuum


Thanks for the help


bob c