A while back, I asked about a starting problem (no idle at start) with my 1991 245. A couple of the suggestions were a dirty throttle body and the microswitch in the throttle linkage. Since the 91 has no external microswitch, I picked up a TPS at the pick n pull, and waited for a new throttle body gasket to come in. Yesterday I pulled the TB, and it was filthy, so I cleaned it and the intake hose. I'd also previously cleaned the flame trap (ordered the kit and they shipped the wrong one), cleaned the nipple in the intake manifold with vacuum to the flame trap fitting, replaced a couple of vacuum lines, and replaced the spark plugs. The TPS on my car didn't click at all, but the one from the yard had a distinctive click, so on it went. Today the car starts and idles strongly, and all seemed well... for a while.

For whatever reason, at times now the car wants to idle at 1400 RPMs. If I turn it off and restart it, the idle returns to normal. Not a biggie yet, but strange. With the old TPS, the car didn't like to idle when first started, but was solid as a rock once it decided to get with the program.

As for the old TPS, I placed it on my desk, and came home this evening to a puddle of used motor oil around it, which came from inside the unit. I'm assuming that being filled with oil could cause the lack of click, but how could it have become filled?

The next problem involves overheating. When I got the car, it would occasionally overheat, not to the point of hitting the red on the gauge, but enough to be noticeable. I pulled the thermostat, and the tower was broken off, so I replaced it. The car ran solid at just below 9 o'clock on the gauge for a week, but it's started a new intermittent overheating cycle. As soon as I notice it, I can turn on the heater and it'll cool off, and then stay that once the heater is turned off. Is it possible that I installed the new thermostat with the vent "clocked" in the wrong position, and it now has an air pocket? The overheating only seems to happen either idling or driving in town at low speeds. The fan clutch seems to be working correctly, and it's moving a lot of air.