2000 Jeep Grand Cherokee - Weird starting

Jeep Grand Cherokee 4.7 petrol+gas sometimes won’t start unless I disconnect the battery.

Car sometimes won’t start, so disconnecting battery helps.

I believe it resets car pc and then car knows, okay I can start now.

My question is how to detect issue and what could be the problem?

Your description is hard to read, but my guess (and that’s definitely all it is…) is that your Jeep isn’t recognizing the chip inside the key fob, but when you disconnect the battery it resets it. Do you have an aftermarket security system?

Hey!

Thank you for your reply.
I am always better in explanation if someone asks a question.

I bought this Jeep as a second-hand car from another owner. I unlock/close the car via Jeep remote.

What’s the best way to find out if it’s an aftermarket security system?

Do you think it could be the problem with ‘recognizing the chip inside the key fob’? Today I managed to start the car for 8x times but then suddenly one time I couldn’t.

I think the Jeeps around this time period had issues with the crank position sensor. I suspect that is what is causing the issue. You could carry some starter fluid with you so when the trouble happens again you can spray a small amount of fluid into the intake. If that doesn’t make the engine fire up then the trouble is most likely with the ignition (CPS) and not the fuel system.