Hello we have a 96 Jeep Cherokee 4.0L that when the outside temp is 90F+ and high humidity chugs and is hard to restart when it dies. At first thought it had to do with vapor recovery(fuel tank replaced) but am now leaning towards O2 sensor. Any ideas??? Am I crazy to suspect O2 sensor??
This is not typical of an oxygen sensor problem. This is typical of a failing ignition component, often the coil pack.
Do you have a Check Engine Light?
We can’t get the problem to happen when a mechanic is handy (typical) Anyway he(mechanic) says wait til the Check Eng stays on so he can get the codes; but once the engine starts the CkEng lights goes out. We are using this truck to deliver a rural mail route so short burst of speed and frequent stops compound the “overheat” aspect. Truck does fine for routine trips about town etc.