Three seconds is way too long for a specific cylinder problem as the crank is spinning at around 600 RPM (10 x a second). The problem is more likely in the "outer emissions tuning loop". It could either be the AMM, idle air control valve, intake air leak, or even a dog slow failing O2 sensor.

I would recommend checking for ECU codes, they might send you down the right road. I'm not sure if this is a LH 2.4 or a LH 3.1 car, but on our 92 245 with LH 3.1, on rare occasion it goes into a cold idle surge cycle that has a period of almost exactly 3 seconds. I believe this is the coarse (slow) adjustment loop trying to cope with a odd situation.

Check codes, check for leaks with a small amount of carb cleaner (or ether). If neither pan out, try disconnecting the AMM and restarting the car, see if things change for the better.

Let us know what you find!

jorrell

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92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!