Lambda sensors

[gesme]

My 1992 940 turbo smokes a lot from first start until burnt off or when accelerating hard or if in slow traffic. Lambda light will flicker if in traffic or when between speed humps i.e accelerate/brake/accelerate. I have removed all the PCV system and cleaned out frequently but still find a small pool of oil just in front of the turbo impeller and in the various hoses. When I clean it out I dont get the light on, or the smoking, but when it starts to flicker I know it is time to clean again. I would love to know how to stop it. I seem to recall reading about draining the Intercooler. Is this something to do with this problem?

[ivor940]

Hi, If oil has in the past got into the ducting / intercooler, and you have stopped further oil from the engine breather getting into the turbo, you still may have oil in the intercooler. The cooler can be easily removed and internally cleaned, but you can let any oil out in situ using the drain plug. It is on the LH side above a small plastic blank plate. You cannot see the drain plug unless you remove the plate. After you fave drained the intercooler, you could also disconnect the over engine breather tube at the turbo inlet hose. Temporaly fit plug cap ( to the outside of the inlet duct connection so nothing gets sucked into the turbo) Then add a bit of pipe to the over engine breather pipe and put the pipe into a plastic bottle ( with a big enough hole to allow air to escape past hose). Put the plastic bottle where it won't catch in moving or hot parts. See if oil is gathering in bottle over the next few days driving. If the car still blows blue smoke ( and the breather is clear - as in you can blow down down the breather pipe and hear air in the open oil cap), the turbo could be suspect or there could be high crankcase air pressure ( due to ring wear) which is prevenving the oil drain from the turbo to the sump. Also, the turbo oil drain line could be blocked, but it is a 1/2" ID pipe with few bends.

ivor940

[gesme]

Thanks for the info, will give it a try this coming weekend, son's football permitting.

[cdunlop]

I have a long standing problem. The Lambda light came on and I had the code 1-2-1 in the ecu.
I have 1) Cleaned out the carbon in the Throttle housing so the butterfly shuts
properly
2) Replaced the Air Mass unit with a second hand one and remade the earth connection
3) Replaced the Air Filter in the intake box.
4) Replaced the Lambda sensor
5) Replaced the ecu thermostat in the cylinder head

Each time I have felt a slight improvement but the Lambda light stays on. Now in the last few days I have notice a pungent smell from the exhaust and a, having excessive fuel consumption. I have check the codes and the 1-2-1 is gone and now I get 1-1-3 and 2-3-2 which suggests the car is running rich. This may be nothing to do with my earlier problems, just cropt up now. I may have also knocked something whilst fixing the other problems.
Any suggestions as I am slowly going nuts over this car.
P.S. I replaced the hall/flywheel sensore about 9 months ago.
Chris

[cdunlop]

Thought it best to start a new thred.