Hey Scotty or anyone else who sees this!
I have a 1988 Toyota Corolla All-Trac, manual transmission and 4A-FE engine with 168,000 miles on it.
Due to some kinda complication, the previous owner had a physical switch installed so the A/C condenser fan has to be manually switched on or off. The problem is, when I turn the fan and A/C on, the engine runs really rough at idle. The roughness goes away when I rev the engine, but as soon as I let off the gas, the RPMs drop dramatically before returning to a rough idle and occasionally it will just stall completely. If I'm driving on the freeway, where the engine stays at high RPMs, then the engine starts to run hot if I keep the A/C on.
The car has a new radiator and water pump.
Any ideas on how to remedy this?
Well when you hooked it up he obviously did not hook up the idle up valve in most situations. When you turn the AC on normally power goes through a solenoid and idle air control valve which makes the car idle a little faster. The compensate for the strain of an AC compressor running. Unless of course the compressor itself is starting to wear out in which case of strains the engine too much and it will always shake
