I have a 93 240 Classic Wagon and it seems to be stumping the mechanic. It has a very erratic idle when the brake is pressed or when in park. It is a low to high idle and finally sputters out and dies on the low end. I have just driven the car 3000 miles from San Francisco to Rhode Island. I had a ton of work done to the car in SF.....it made it to Rhode Island but finally broke down. Before I left SF I had the air mass meter box and thermostat replaced, it had the same issue it is having now only the engine light was on with the oil light. After those parts were replaced they also cleaned the throttle and inspected the idle control valve. The problem seemed to have progressively come back after about driving 2000 miles, there is no engine light on...only the oil light. Again this only happens when the brake is engaged or in park. When the car finally broke down, I was driving through hard rains and hit water that was up to the wheel wells. I was able to pull off to a parking lot, but while pulling off was giving it full throttle and it barely made it to a spot in the lot....then died. An hour later it started up again only with the same problem, oil light on, low to high throttle and barely drives.

Any suggestions. Kind of a lot of info, sorry about that.

thanks.

It has a very erratic idle when the brake is pressed or when in park. It is a low to high idle and finally sputters out and dies on the low end.

typically what you describe is caused by a large vacuum leak/s. check the intake manifold gasket and tightness of the 8 nuts. check the line and one way coming out of the brake booster.

you need to put a mechanical gauge on in temp place of the oil sender to verify you have normal oil pressure. if you do look for a sporadic short in the wires behind the alternator with black wire attached to the sender. if the pressure is low you have bigger worries than bad idle. look for a loosened oil return line o gasket into the block only visible with the oil pan OFF.

also pull back the rubber cap from the lone signal wire from the o2 sensor at the passenger firewall and measure voltage swing to make sure the sensor isn't on the way out. a failing o2 sensor can make for bad idle, stalling, running rough, etc since it primary to the ecu to set fuel trim.