Was on my way home today on a 120 mile trip in at/near 100F temps when after about 60 miles at 70-75 mph highway speeds with the AC on, my '96 Cherokee (4.0L / manual tranny) with 187,000 miles experienced a power dropout - no response to the gas pedal but not stalled out either (no dash lights). No CEL either - and about 15 seconds later it returned to life and drove fine. Another episode occurred in about 100 miles - same event. This did not occur at all on the entire trip up in the morning - just on the way home.

No restart problems when I filled up at the gas station - did several starts to be sure. No problem. No change in idle, oil pressure, water temp or charging on the stock analog gauges while driving. Got home fine and thought maybe it was some bogus gas near the bottom of the tank (1/4 tank left). Vehicle has new plugs, wires, cap and rotor as of 6 months ago - all fluids are kept tiptop. Got an average of 18.3 mpg on this trip too - not too bad with the AC huffin'.

I imagined the fuel filter is starting to fill up with crap as this is a largely overlooked part - and no telling when it was last changed. Intermittent fuel pump performance perhaps? Felt no firing on any cylinders (really dead!) so also wondered if the coil was dying, but then it ran fine. This was the first longish drive I've taken the old girl on and, considering the temps, wondered if I'd have any issues.

Any ideas, gentlemen? Please advise whatever checks I can perform to determine the cause. Many thanks!

 

Bumpity bump...

 

CPS is known to have heat failures. For sure replace the fuel filter.

 

It does sound like you CPS is on it's way out.