On my 4.5 when I adjusted the timing after a valve adjustment I found that setting the timing to 5*ATDC (per book) produced poor running, run on and hard starts. While setting the timing I also observed an additional paint mark at 10*BTDC. I took a gamble, disconnected the vacuum to the distributor and set timing to 10*BTDC. Upon reconnecting the vacuum, timing was sitting about 2-3*ATDC and the car ran fine. Try setting to 10*BTDC with the vacuum disconnected and plugged. Reconnect and see how it runs.
For the manifold pressure sensor hose I found the 5/16 fuel line worked good. It fit snugly on the sensor, but loose on the manifold stub. A small hose clamp holds it tightly to the stub, but is a real PITA to get a screw driver on. Found my fabric covered line was rife with small holes, changing the line dramatically improved the running condition.
Hope this helps
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.
Last edited by MikeTangas; 03-19-2002 at 01:21 AM.