My 1999 escort 2.0L sohc is having idle issues. It idles perfectly after a cold start. When the engine warms up, the engine starts to lope, and often dies. I've searched for leaks and replaced parts that are the most obvious possible reasons. Also replaced some parts that were questionable. The head was cracked and the gasket blown. It was obviously like that for quite some time. There was only a leak between the coolant and cylinder.
So far I've replaced: fuel pump, fuel filter, timing belt, timing belt tensioner, water pump(trashed), thermostat, cts, radiator fan switch, head w/gasket, radiator cap, iac valve, ccrm, pcm/ecu, tps, cleaned maf sensor, cleaned intake, cleaned injectors, new injector o-rings, spark plugs, coil, checked and cleaned pcv valve. Knock sensor is ordered, and O2 sensor will be installed soon. I've started throwing money at it, and I'm about ready to scrap it. Any help is appreciated.
Forgot to mention: The loping goes away with the headlight and/or A/C on. The car previously would overheat without the cooling fan switching on, hence the cooling parts being replaced.