E30 Zone

The idle on my M10 has gone a bit funny.

When cold it's a bit low (650rpm), when at normal temp it's a bit high (850-900rpm) and sometimes sticks higher (1000rpm). I can't see any vacuum leaks. Oddly, when the lights are on, the idle behaves better! Also the car sometimes struggles to start without right foot, i.e. catches and dies or catches and struggles up to correct idle.

Any idea what's going on?

I took off the cold start injector and it was covered in black gunk, I cleaned it with carb cleaner and it's made no difference. Could it be broken/leaking causing the poor start? Is it worth taking the ICV off and cleaning that with carb cleaner?

Stewart

do you have the aux air valve along the side of the inlet manifold dude ?, if so, remove and test with a 12V feed, should be "open" naturally when unpowered, and then over 5 minutes slowly close with 12V applied.

I've seen M10's with a "waxstat" setup too, a water heater version of the above

either are known trouble spots, clean, test, replace ?? as required.

HTH

Do you have a pic of this, or a diagram on realoem so I know what I'm looking for?

Cheers,

Stewart

I have checked and I have an aux. air valve (bolted near the cam cover, two air pipes and plug?) so I'll clean test and replace as required.

Ta,

Stewart

Took the auxilliary air valve off, sprayed for a long time with carb cleaner and put it back on and the idle shot up to 1200! Good methinks? Anyway, I've now got to get the idle back to normal as past owners, me included have probably fiddled with the idle to compensate for the way the AAV was behaving. Is there a scientific way to adjust the idle screw? When hot? When cold?

Stewart

stranter wrote:Took the auxilliary air valve off, sprayed for a long time with carb cleaner and put it back on and the idle shot up to 1200! Good methinks? Anyway, I've now got to get the idle back to normal as past owners, me included have probably fiddled with the idle to compensate for the way the AAV was behaving. Is there a scientific way to adjust the idle screw? When hot? When cold?

Stewart

Anyone?