I have a 2001 Jeep Cherokee XJ. last weekend after the rain, I went off-roading and ended up hydro-locking my engine. I took the spark plugs out and blew all the water out of my engine. I then replaced all of the spark plugs. I also checked my air intake and found a little water in there so I dried that out. After all of that, my car started up just fine. I have been driving it for a couple days now and recently my car has been rough to start, it has a rough idle and I have to hold the gas a little to get it up to rmps. After a few minutes of warming up, I am able to let off the gas and let it idle. it still has a rough idle then and driving down the road I get an occasional stutter and almost like misfiring. Any ideas on how to fix this problem??!!

 

Any check engine light? Even if no, I would scan the computer as it's possible you have a pending code.

With water intrusion as you mentioned, the #1 engine management sensor that gets affected is the throttle position sensor. It hates water.

You could try unplugging the sensor and spraying the connector with electrical contact cleaner but If you get stuck with this, you may want to replace this sensor. Do yourself a favor and buy a genuine Mopar/Jeep TPS for best performance/reliability/mating with engine management of your 4.0 engine.

Good luck and keep us updated!

 

Water in the fuel??
Put a vacuum gauge on it and measure intake vacuum. A brittle hose might have cracked during the repair process.