I just bought a 2003 2 door 4WD that is stock. I have put a new air filter and new tires on it. It has only about 83,500 miles. No mod's. We have had about 2 weeks of rain here everyday. I park the SUV outside. Yesterday, I tried to start it and it would spin over but the engine wouldn't fire. I was turning the starter for short bursts. Some times the engine would cough, and not fire. Then it would sputter a few times and not fire. I kept cranking in short bursts and it finally cranked up and fired.It then ran well---smoothly-- after that. I drove into town about 13 miles away. After that, it cranked up and ran on first turn of the key. I have not changed the plugs , s/p wires, O2 sensors, or fuel filter. After searching the forum for dampness related hard starting, one thing that is frequently mentioned is the Ignition Control Module=ICM. I have only noticed the crank and sputter or cough a couple of times before. But these occasions were few and far between. When they happened, the engine would catch and fire up on the next key turn, so I ignored it. What do you think I should check and /or replace? The battery seems strong and reads 12.64 Volts on a DVOM.

 

It's almost 99% not your ICM. Treat your new truck to a nice new set of wirers, cap and rotor. Delco is best if your not on your last nickel.

When other problems come you can post that you did it.

Also start shopping for a fuel pressure gage now so you don't put yourself in the position of "I need it today" and have to pay triple.

Trust me, at some point in the not too distant future you WILL need it.

 

I agree, only thing I would add is to make sure you put dielectric grease in your spark plug wire boots at both ends. I like to take an old screwdriver and smear it on the inside of the boots while trying not to get much on the connections. You will notice that your distributer cap sits nicely underneath the rear hood seam so everytime it rains water will drip right onto your distributor cap. Mine ran poorly everytime it rained until I greased my wire boots.

 

Put a new cap and rotor on it first, using ac/delco parts and it will crank when it is damp outside

 

Tuesday 7-16, was the first day without rain in a long while. Of course, when I went out to crank it this Wednesday morning , it did start up and ran without a stumble or sputter. Since I had put the battery through a lot two days ago when it wouldn't start, I checked the battery voltage before stating--12.54 Volts-- and while idling--14.55 Volts. Seems both the battery and alt. are healthy. It started up and ran fine while doing errands in town 13 miles away.
Now that is it sunny, I am seriously thinking of getting a water bottle and spraying the different trouble sources one at a time and see if I can recreate the problem: The distributor cap, the spk/plug wires, and the crank position sensor, ICM, and so on. I know some are thinking--- why make trouble? It would be great if I could isolate the problem. I know the problem will come back soon. I am glad I have other transportation.