I have a '73 ES that is currently running rough and then dying. In the process of giving it a much over due tune-up I discovered that plugs were very dark and the engine appears to have been running rich. Accordingly I've been checking the vaccuum system. I've come to pressure sensor and the resistance across each of the coils matches that specified in the manual. My question is:

**How do you check whether or not the diaphragm is broken without cracking
the damned thing open?

Any suggestions would be much appreciated.

F.I. ENGINE TEMPERATURE SENSOR!!!! Please check this part before replacing the presure sensor. It can cause these semptoms and is much less expensive. It can be checked by monitoring the resistance at known engine temperatures. You can find a chart with the proper resistance listed online but I forget the web address. But someone on here will know it.

Thad
Seattle

http://www.icbm.org/erkson/ttt/engine/fuel_injection/d-jet.html

Try unhooking the line from the manifold and suck on it. No air should leak.
bob


71 1800/97 850glt/82 240

....and while sucking on the hose, you can probably see a change in resistance across the contacts

Thanks a lot. Sounds pretty simple.

If the sucking suggestion bothers you, try using a vacuum pump. Pull a bit of vacuum (14 in.)and see if it will hold for 3-5min. If it does, its good.