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1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Hi, recently acquired a 1998 (May 88 build) C900 Aero (SPG in the USA) in Odorado Grey with Dover leather interior. I have always wanted a C900 Aero and enjoyed some normally aspirated C900s in the past. This new addition sits nicely next to my 9000 Aero MY1997. Anyway, have been sorting a out some minor issues with car and spent part of today testing the cruise control which does not work. Here's a summary;
1. Disconnected the main vacuum line at the y (T) piece from the black lug. I applied vacuum (aka sucked on the line and held negative pressure for several m inutes. The throttle plate activated and stayed in position until I released pressure.
2. Checked the boost limited switch and found it would not hold vacuum so used some plumbers tape around the screw and this solved the problem
3. 'Sucked on the black lug of the vacuum pump but unable hold negative pressure. Suspect??? Should it hold negative pressure by this means??
4. tested indicator stalk control and this appears to be functioning ok with the correct volt outputs based upon different switch actuations.
5. I am assumming the cruise ECU is ok given this is an earlier model. I understand that later model C900s (1990 omwards) seemed to suffer unusually high failure rates of cruise ECU (silver ECU???)
So, where does this leave me?
Well cruise still does not work. I am assuming that everything downstream of the main vacuum line is functioning correctly. I believe the electrical functioning of the stalk switch is OK. Unsure about vacuum pump and am assuming the cruise ECU to be ok. Also assuming the vacuum bellows, etc are ok because that port of the system appears to hold negative pressure without any loss. Don't have a spare working vacuum pump to swap.
How reliable are the vacuum pumps? Are they a typical cause for failure of cruise??
Thoughts and comments please
Cheers
Tony
posted by 203.217.91...
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