Any suggestions?

[eelwell]

I own a 93 LS 400. I changed the plugs, caps and rotors. Car ran great for a day. I took it to the car wash to clean the engine. Drove a mile or two from car wash back to my garage. Car was off for about an hour. Strarted up fine, but started missing, rough idle and sound like timing is way off. I thought something had gotten wet. Not the case, it has been 3 weeks or more since this started. I check caps and plugs, they plugs are black like it is running rich on fuel. Replace spark plug wires. No better. It idles better with the wire to the cam pick up sensor ( not sure if that is the correct name for that ) on the drivers side cam unplugged. Also idles much better with the AC on. Did I get some sort of fuel sensor wet and ruin it? I'm at a loss!!!

 

[Zuffen]

I can't think of any sensor that would fail due to moisture ingress.

You could find some slight corrosion on a terminal is giving false readings to the ECU.

To be honest I can't suggest where to start.

The air con has an idle up feature run by the ECU.

The plugs will normally be black due to unleaded fuel.

Have you checked the cam timing marks are as they should be?

 

[samsdad]

you have water in the airflow meter plug.. Check and clean it

 

[eelwell]

Thanks for the tip. Can you tell me how exactly to do that?

 

[XR8tt]

I assume ?? Unplug and spray with WD40 or straight metho ???
Seems it was condensation ?? Dist caps dry ??? Plug leads around plug o/k ??