88 Cherokee 345,000 miles runs great on highway. But it has an intermite problem. It will stall sometimes and sometimes it won't. I can sit at a stop light for 2 or 3 mins idle just fine, then the idle will drop to 300 rpms them just stalls. I have replaced all the parts you here about on the internet. Such as plugs,wires,cap and rotor, TPS,idle position sensor,CPS,air filter,fuel filter,fuel pressure at fuel rail,map sensor and cleaned trottle boby. Sometimes when it starts to stall I have to pump the gas pedal fast and it will stay running. The only thing that I notice at high speeds is a slite hesitation. What next a new computer? I could use some real help with this. problem.