900i starting - CIS experts!! Help!!

[saabfan9]

just was not seeing it last time i hooked up...maybe i'll try to find a different meter....i do connect at that 2 wire open connector by the fuse box right? 1 lead in each or is 1 lead to gound?

[markg9]

positive from meter to brown/white wire and negative from meter to ground

[saabfan9]

ok so i got to play with her.....i did hear the buzz from the valve.i also tried to unplug the o2 sensor and i still have the same results....starts perfect runs decent for about 2 minutes then slowly the idle will drop and die out then you can forget about restarting until she sits for a few hours...any ideas? (i did not check the mixture with the dwell yet)

[markg9]

Now is the time to check the mixture with the O2 sensor plugged in. At least then you can tell me where the needle swings. If the O2 sensor is working properly you can tell via the meter if it's running rich or lean,

[saabfan9]

I'LL try that tomarrow thank you for the help...i'll let you know what i find

[s900t8v]

I wonder if you tried my advice to test the warm up regulator? Btw mark the WUR plays a vital role at all times regulating control pressure. Cold or hot.

[saabfan9]

I did and that made a huge difference (repaired the lines and cleaned the black gunk out of it) before that it would never idle on it's own no matter what I can now start the car with no problem and be able to get out of it without watching the throttle.....starts perfect now idle starts off around 1500 as she warms (within the first 2-3 minutes) idle slowly comes down into a normal range but then continues to drop past 800-700-600-500 then will die out and be a total bear to restart (acts like it's loading up and flooding out...best to wait an hour or so to restart

[s900t8v]

Good you made progress that still sounds like the control pressure is rising too high due to a blocked or damaged warm up regulator or blocked metering port inside the fuel distributor. The only way to verify this is with a fuel pressure test.

The funny thing about k jet is that as the control pressure increases the engine leans out. Pressure increases due to blocked components. Even more counter intuitive is that if system pressure is too high due to a blocked fuel distributor the atomisation quality at the injectors will decrease and the car will flood (lean due to poor atomisation but large fuel droplets make plugs black)

Blocked warm up reg and or fuel distributor are by far the most common cause of the symptoms you describe an simply tryin to clean them will not suffice a rebuild with new internals is required to bring them back within range.

If leavin the left fuel line to the warm up regulator loose during runnin helps prevent the car from stalling then you know the problem is the one I have described. The 02 sensor rarely has enough input to stall the car.

Hth

[saabfan9]

guys thank you very much for the help..as soon as it stops snowing here in Chicago i'll dig it out to test further...chris