Normally this is the Water Temp Sensor. It tells the CIS-E system when to make the mixture more lean or more rich depending on engine temp. Also fires the cold start valve. Idle will wander when cold and this is bad. At least mine did.

Edit: Check the EHA thread near the end I have posted the chart of values for the Water Temp Sensor! Also make sure you check the wires, my connectors fell off my wires and I had to improvise and make new connectors!

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~Jamie
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2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....