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idle speed regulator 900 94

A few weeks ago my '94 945T was idling rough, with a 1-2-1 code. Changed plugs, rotor, cap, wires, air filter and AMM. Car still idled rough, ran fine at speed. Got good advice here to de-ox connections at AMM, check integrity of battery cable, clean battery connections and check for air leaks on the AMM line. I did all this and .....engine still idles rough. Is my next step replacing the idle speed regulator, and if so where is it located on the 945? Appreciate the advice.









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Re: idle speed regulator 900 94

My BMW required cleaning of the idle

speed regulator, I used carb cleaner.








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Re: idle speed regulator 900 94

Terry,

You might check the two FI grounding points attached to the fuel rail brackets. These can corrode and/or come loose affecting fuel injection performance. I'd clean the connections and apply a smear of dielectric grease and snug them down. They are easy to get to.

Also and perhaps more likely, a dirty throttle body can produce a rough idle. Remove the intake hose and using a mirror and light check the inside of the throttle body. If dirty you can clean it up with a lint free rag soaked in intake cleaner. You can clean the TB relatively well in place but a good cleaning requires removing the throttle body. You'll need a new gasket if you take it off.

The idle valve is a small cylinder located beneath the intake manifold. There are two small rubber hoses running in and out of it and a wiring connection. One hose is connected to the metal intake duct (On the Turbo Engine)... the other comes from the valve into the intake manifold. Sometimes removing the constant idle motor and cleaning the gunk out with carb cleaner will restore them ... often if they are suffering from serious wear, a new part is the only practical solution.

I would clean the throttle body first. A dirty TB is quite often the cause of rough idle.

Hope this is helpful.







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