940 Idle Problem

did u change the injectors did u have ur injectors tested if u did swap them out as well and i mean hot tested what coulor are they? and have u got a car steh to listen to the impulse i.e listen to it to see if any are difrent one more thing did u fir the second fuel pump and check the vac swtich ?

When you did the swap did you change the fuel ecu as well as the engine ecu? Are the leads rotor and distributer cap in good order?

When I took the EGR stuff off I swapped the inlet manifold for a normal one and swapped the injectors over. Fitted new seals as well. I haven't had them checked but the doner car drove ok so I'm not sure. I swapped the Engine ECU over and did the ignition one as well after realising it was different. Is there another one I don't know about. Wouldn't surprise me as this is bound to be something stupid . I think the leads are ok, and the cap is recent. I have put a message on Turbobricks and someone suggested that the Compressor Bypass Valve might be causing the problem. Sounds likely. if the excess boost pressure can't get out it could raise the idle speed (perhaps). I have noticed an odd noise when I lift off and didn't know if it was normal or not.

That answers my questions then, sorry I have do idea.

Thanks for the reply though. It could be that the plug leads are getting old, someone else suggested that but I can't see they would give such a strange fault. If it isn't the CBV then I might try leads just in case as I'm rapidly running out of sensible ideas.

Did you ever get to the bottom of this Steve? I now have a similar problem with my 240 (b230fk), idles at 1500 rpm half the time, I am getting codes 311 (signal absent from speedo sensor) and 144 (no load signal from fuel injection) The lambda light is on. I read the codes today and reset the ecu, after a 20 mile drive the light was still out but the idle was at 1500 rpm. on the return leg the light illuminated on start up. I have recently fitted a different instrument cluster from an earlier 240 (b230e) due to the original one having a failed rev counter, as far as I could see it is exactly the same as the one I replaced. Otherwise the engine runs smoothly as it should.