Ok, i have Grand Cherokee Limited 1997, back wheel drive, 4.0L, 6 cyl.

When it humidity, moisture, dampness or cold weather my car starting with difficult from 5 or 6 time of starter turn. After that when engine start it can be work about 1-2 minutes or even 7 minutes and after that going off like somebody switch off ignition switch, electrical dash board is working and showing everything level of fuel, temperature of engine, battery.. etc. And it can repeat about 3 or 4 times before engine get regular temperature. After that it`s run good. I can drive everywhere, do my business. Stop the car, turn engine off about for 30 min and after this 30 (or 40) minutes i can start engine again without any problem.

So
1) when engine is cold starting with problem.
2) when engine is hot it`s works perfect.

Here is the list what replaced already:

1) Fuel pump and filters
2) All distributor
3) IDLE Valve
4) Oxygen Sensor
5) Crankshaft Position Sensor
6) TPS - Throttle Position Sensor
7) VSS - Vehicle Speed Sensor
8) Board computer (PCM)
9) All sparks and cables to them
10) Engine temperature sensor
11) Catalytic converter
12) Battery

So! Is anybody have hypotheses what it can be?

 

Mine is doing the same thing. I am going to replace the ignition switch. I will let you know how it goes. The part is only like 10 bucks by the way.

 

Yes please, let me know, because i have it too - new one. If after that everything will be Ok with your car, than i replace mine too

 

Ok just got mine done. It was tuff to get to. Its on the top of the steering column behind the dash. The directions I had said to remove the steering wheel and a bunch of other crap. I think that you could just drop the steering column with two bolts after removing the bottom cover panel (there is a screw hiding behind the ash trey) and then remove the two bolts that hold on the ignition switch and just replace it. There is a rod that goes down the column and ties into the switch. There is a couple other things that are tied into those screws by the way. You can see them from the left side of the column. When you take out the old one just turn it over and put the new switch in the same position as the old and then re-install it. Here is the site I got the instructions from. It was very limited but I figured it out. It would be helpful if there was pictures but there was not. Anyways here it is http://wiki.answers.com/Q/How_do_you..._Jeep_Cherokee Hope this helps you.