Originally Posted by jeep373
I have a 1997 Grand Cherokee with A LOT of miles (373578) 6 cyl. We have changed the CPS and it was fine for a few days then started to stall again. I would be driving along and with no warning and stall. No dash lights nothing. It starts right back up and goes and might be fine for a few days before it happens again. I have noticed that when I step on the gas the car acts like it is off no power. Do you think I got a bad CPS?? Or is there something else going on.
What area are you driving in?
I had a 95 4.0 ZJ with high mileage and it absolutely refused to run well with regular or premium fuel in the LA basin. On first arriving I still had some decent Utah gas in it and it ran rather well... but after the first fill up it refused to idle or run smoothly at lower speeds and kept it up until I got to Vegas and put in real gas again.
I wouldn't think this is the CPS, but you can pull your fault codes using the key on off on off on and see if it is storing any related ones.
The no dash lights [assuming you mean that everything on the dash goes out] would make me look at the grounding, where the ZJ was infamous for poor grounding.
Remove and clean and tighten the ground from the alternator to the chassis at both ends. Also, there should be another ground back near the rear of the engine to chassis. I just put in a heavy braided cable from the side of the engine to the same
ground point the alternator uses.
From there, its a guess. Dirty throttle body sensor [a dealer can clean them with a treatment, but if you do it, use cleaner and a tooth brush] to really old plug wires to really old plugs.
But if you really are losing all the dash lights, start by looking at removing, cleaning, all battery connections and in particular the ground.
A bit further out would be the fuel pressure sensor that shuts down the engine and fuel pump if it doesnt see enough pressure with the engine running.
If you have any aftermarket security disables, bypass them temporarily.
Good luck... pretty much "the entire vehicle" is on the suspect list.