Posted this on saablink.net and the forums at my site a few days ago...
My 81 turbo is exhibiting a starting problem when cold - it's fuel-related since the engine fires without a problem after a few seconds of cranking then the revs die down and the engine stops. Cranking again gets it going. I'm thinking either fuel accumulator or the fuel pump check-valve but haven't yet done a lot of diagnosis. I have a K-jet fuel pressure testing kit so I'll try that on the weekend and see what that reveals, but if anyone can think of anything else, I'd appreciate your ideas.
As an aside, I need to see what's going on with the cold-start injector control too - there's no lambda control so I don't quite know what drives the cold-start injector if anything, and it's possible that it's not doing anything. My understanding is that when cold, the thermo-time switch should allow the cold-start injector to run for up to 10 seconds when starting, but the Bentley manual is completely wrong for my car as all the sections talking about emission control, etc. assume the car has the extra relay panel which apparently all the US/Canada c900's were equipped with.
and yesterday posted this...
Started checking out possibilities today. First thing I did was see if I have a matching spare warm-up regulator in the shed.
The warm-up regulator fitted to the engine in the car ('H' engine, 8V, non-APC) is the -070 version (Bosch # 0 438 140 070) while the one fitted to the cylinder head I removed from the 82 non-APC turbo car last year is the -085 version (Bosch # 0 438 140 085). According to the ATP Electronics warm-up regulator listing, the -070 version is used on with turbo 'B' engines only, and the correct version for my engine should be the -085 or -102 version.
Anyway, I'll be doing the full range of checks tomorrow (electrical, etc.) and I might also connect in my K-Jet fuel pressure test meter and see if the the measurements are within the specifications in the Bentley manual.
Has anyone encountered any unusual problems with warm-up regulators on non-APC turbo 8V 'H' engines in 81 or 82 build-year 900's? I haven't ruled out other things yet (like the fuel-pump check valve, or the fuel accumulator) and the K-Jet test kit will help to identify any possible problem with that part of the fuel system if indeed that's where the problem is.
Another possibility may be the fuel-pump relay since it's the longer metal-can type with a 'terminal 50' connection. Not sure if I have a spare, but I have a spare fuel pump relay from a non-turbo 8V car that could be used if need be.
I'm going outside shortly (nice sunny winter day in Sydney!) to do the electrical testing and if need be hook in my fuel pressure tester...
If anyone can think of something to consider, please let me know.
Thanks,
Craig.