Last night we had a huge rainstorm. This morning it took about 5-10 minutes to get the car started. This isn't the first time it's happened. I was thinking the opti got wet, but how does that happen with the car sitting still and hood closed? Anything else that could do it?
If it is the opti, what can I do to prevent it from happening again?

 

that happened to me before... it was the ignition coil.. after it rains that extra moisture just sits in there and if your coil is going bad anyways it just does fire with that extra moisture

 

I have the same problem. As well, sometimes it will cut out during a rain storm, even if I don't hit any puddles.

 

Brad/Matty:

For me it was the O2 sensor wires.

I wrapped and insulated the wires and same for the starter motor. The connections get wet.

I can drive through puddles now.

 

Same here, my car used to stall out in puddles. Turned out to be the ignition coil and a corroded coil wire. (at the time replaced under warranty)

Word of caution, this is what led to my experience with the now infamous "low rpm hesitation/stumble". I think it had damaged my opti as well which I replaced a year or so later.. which kinda fixed the problem.

 

it did cut out int he carwash the other day too, but started back up after a few seconds of cranking. Just not sure which direction to look...coil or o2...how do you diagnose which it would be?

 

I have that problem only it wont start the next day after a heavy storm. I checked the coil and my o2's are new. I think mine is the opti, I have new wires and new plugs too.

 

Its not because of bad O2s.

If you get your car in the air you will see that the O2 sensor wires travel through a black plastic sheath. After that its wire and right before they go inside the O2 sensor body they sometimes have no sheath on the wire because it has slipped back.

Use some good electrical tape and tape up the wires after they leave the plastic sheath and tape all the way over the body of the O2 sensor. Make sure its water tight.

Same with with the starter motor wires. Tape the wires and terminals.

Don't go to the automated car washes that wash your car from underneath with a high pressure spray!!

Other than that, make sure you have dielectric grease on the plug wire terminals inside the boots.

 

Not sure how it could be related to the o2 sensors. The car doesn't use the o2's until they are warmed up and the computer goes into closed loop mode. So when you initially start the car, the o2 sensors should have nothing to do with the car running. (Just a guess ) To verify (and I've never tried this) umplug the o2 sensors and the MAF sensor and try to start the car. It should run, but it will throw a couple SES codes, run in open loop mode and will turn both fans on.

More likely it would be due to the coil, coil wire or as gripenfelter mentioned, the starter wires.

 

I have this problem. It's been doing it for a couple months now. After rain the car will not start. Sometimes it doesn't start for a couple days sometimes a few hours. I assume the seal on the opti is shot & letting moisture in. I don't see how it would be my coil or coil wire as they are both about a year old. I am running an Accel supercoil.

The car cranks fine, though.

 

The car cranks just fine though, so what at the starter wires could cause the not starting problem?

And I still am not sure how water could get in the opti with the car sitting still and hood closed...that would take a lot of humidity I would think to gathr enough moisture to make a difference. I could be wrong though...

 

Maybe its because I have a cam.

My car stalls as soon as it starts if the O2 sensor wires are wet.

Make sure all your plug wires are secure and have dielectric grease on the terminals.

Does you car turn over when its wet? If not its the wet terminals on the starter.

If it turns over but doesn't catch its your plugs wires.

 

same thing happened to mine last fall. after it would rain, the car would just crank over and over, but wouldn't fire up. mine ended up being the coil and coil wire were corroded real bad.

 

I've checked my plugs & wires and all is well. My car still does it, though.

After reading this thread I may replace my coil & coil wire. Hopefully it is that & not the opti

 

Pull and check for visible corrosion on the coil wire and the coil terminal, replace if neccessary or clean the areas.