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Re: Head Scratcher 99 CIS issues Posted by Gary Stottler [Email] ![]() ![]() In Reply to: Re: Head Scratcher 99 CIS issues, Jordan, Sun, 7 Jul 2019 10:15:30 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I agree it's a head-scratcher. Since it's not dying completely when it has an "epsisode" it seems much more likely to be fuel than ignition. Something is either sticking (mechanical) or going on/off (electrical). Based on what you've reported, I still wonder about the Lambda system doing something intermittent or the airflow/fuel distributor "sticking" for some reason (could change with temperature) so that the fuel flow to the injectors gets "stuck" at a low level when you open the throttle. If you have the Saab 99 service manual for M 1975-1980 USA, that's sort of the bible for working out this stuff. Pages 254-20 through 254-34 give a very complete description of the Lambda system and troubleshooting. It does indicate that for 1979 non-turbo cars, the micro switch should drive the pulse relation to 45% +/-10% and for 1980 non-turbo cars to 65% +/- 10%. Only the Turbo should got to 80$ +/- 10%. So I think that part is OK based on the reading you got, at least it's not off enough to cause the drastic problems you are seeing. If you don't have the manual, send me an email at gpstottler at gmail dot com and I can send you some pix of various parts.
The only other thing worth looking at is the thermo-time switch, vacuum impulse contact and cold start injector set-up. That can cause cold drive and cold start issues which seem to be fine here, but I suppose that if the cold start injector is dumping a bunch of unneeded fuel in there when the engine is warm you could get some driveability issues as well.
Best,
Gary
_______________________________________ Gary Stottler
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