It rained pretty good here last night and this morning. I ran through about 4 or 5 deep puddles of water today. After the first one I noticed that the check engine light was blinking on and off. Then it would stay on constantly. Then start blinking. I took it too AutoZone and had them do a diagnostic on it. It said the 1 through 3 are misfiring. It idles and runs alright. But the CEL is still on and blinks. There was water all over the engine. I drove for at least 50 miles with it doing that with no noticeable problem. Plugs are only about a year old. Could I have gotten water in the distributor cap? Or something else? Any ideas? Thanks

 

How old are the plug wires ? Seems every time I see or hear of misfiring and rain/water, it boils down to moisture on/around plug wires. Went through something similar this week myself. Washed engine, next day misfire, water on plug boots (on 4.6L boots sit inside head). Dry the boots, no more misfire.
Go figure, the wires are the originals (1997, 125,000 miles). Bet they're due.....

 

If you can find a distributor cap under your hood, you'd better change it!

Seriously, yoiu have to specify which engine you have. Certain ones have common faults.


Steve

 

Plug wires are the originals. It's a 98 with about 130k on them. Plugs are about a year old. Engine is a 4.2l. You could see where water had gotten all over the engine. But it was pretty much dry by then. While I had the hood up I decided to get the crud off of my battery leads. I disconnected them and cleaned them. When I put them back on, then started the thing up, the CEL was gone. I did notice something else though. When I give it some gas, it shudders for a second or two then stops. It just noticed that today.

 

That shudder is your misfire and is what needs attention.

Steve

 

CEL's will go away when you disconnect your battery. They will pop back up when your computer realizes it still has a problem.

 

The CEL has not come back on. I started it up twice this afternoon and it's not shuddering anymore. I don't know it the problem is still there or not. Is it okay to drive it? And what should I do about it? Change out the wires?