[Jay Laifman]

I have a 73.5 CIS 911. I've had it for 26 years and over that time, the original WUR was replaced with an 009. I still have the 001 in the garage. My car has been having a cold starting and initial running issue and I'm trying to track it down. In the meantime, I've always wondered if I should get the 001 fixed, or made adjustable.

The curves are not the same, so I've aways thought that perhaps my car is not running as optimal as it should. When I compare the 001 chart to the 009 chart:
001: 1.4-1.7 bar @ 10* to 2.5-2.8 bar @ 35* (range of about 1 bar)
009: 0.5-0.8 bar @ 10* to 2.0-2.4 bar @ 35* (range of about 1.5 bar)

Doesn't this mean that I'm running too rich or too lean at one end or another? FWIW, I just measured mine and I'm getting .5 bar (cold) to 2.9 bar (fully warmed up). So I'm even higher than I should be, meaning I'm richer when cold and leaner when warmed - I think. Does this negatively impact the 73.5?


FWIW, after sitting for 12 hours overnight, my car does not like starting in the morning. It has to spin on the starter for too long, and it runs rough for 3 minutes or so. But, interestingly, 12 hours later when I'm leaving work, after it sat for the same amount of time, but in a warmer garage, it starts fine and runs fine immediately.