What a great site! I have a question. I have a 1999 Jeep Wrangler 4.0 L. We had a tremendous amount of rain here the past week. Yesterday morning when I went to start my Jeep it runs rough, wants to stall, hiccups and the check engine light is on. The temp, oil, are ok. Could it be moisture? Any suggestions? Thanks! :screwy:
I had a similar problem on my 95 Jeep Grand Chrokee, and it turned out to be the oxygen sensor. It is easy to test and replace if needed.
Moisture can always present a problem with spark-ignited engines. In
addition to those items already mentioned, take a good look at the spark
plug wires (and their boots). If possible, raise the hood in darkness (but
not in a closed garage!) and observe the running engine. Watch (and listen)
for sparks jumping from wire to wire or from wire to ground.
Another thing to check for following heavy rains is exhaust system restriction. This often happens after driving through deep standing water, and is caused by structural failure or collapse within the exhaust system, most frequently in mufflers, resonators or catalytic convertors, though it can also happen within a length of pipe. With single-wall pipe, it is readily apparent if a pipe has collapsed. Not so with the rest of the system... :)