Car stalls when it rains.

[SagaLore]

My 04 Dodge Neon completely stalls out when its wet outside. Its fine as long as I'm driving it, but as soon as it goes idle, the engine dies. I have no problem starting it back up, but it will just die again when it idles.

I plan on replacing my spark plugs and distributor cables... anything else I need to look out for? I get regular oil changes, occasionally run the fuel injector cleaner stuff through it, and replace my air filter once a year.

 

[zoiks]

Probably moisture getting into the electricals. I would look at the distributor first and wipe it inside out. Look for any signs of moisture. Try starting the car after you put it back together.

 

[nakedfrog]

Plug wires, right? Not distributor cables?

 

[SagaLore]

Originally posted by: nakedfrog
Plug wires, right? Not distributor cables?

Uh... yea, those.

Originally posted by: zoiks
Probably moisture getting into the electricals. I would look at the distributor first and wipe it inside out. Look for any signs of moisture. Try starting the car after you put it back together.

Would it help for me to wipe it out and make sure its dry, and spread vasoline like gunk to block moisture?

 

[boomerang]

In a darkened garage, raise the hood and use a spray bottle to mist over the spark plug wires. Check for arcing. If the spark plug wires need replacing you'll see sparks jumping around. You may see them without misting.

I'm not sure if your car has a distributor. But if it does, look at the underside of the cap. Looks for cracks and carbon tracking. Look for buildup on the posts inside. If you see any of this, replace the cap. replace the rotor too.

Don't spread any Vaseline like gunk.

Edit: There is no distributor in your car. How many miles? Any warning lights on?

 

[SagaLore]

Originally posted by: boomerang
Edit: There is no distributor in your car. How many miles? Any warning lights on?

No warning lights, I think 57,000 miles.

 

[nakedfrog]

Yeah, I have an 04 Chrysler and IIRC the plug wires are scheduled for replacement at 45k.

 

[boomerang]

Originally posted by: SagaLore

Originally posted by: boomerang
Edit: There is no distributor in your car. How many miles? Any warning lights on?

No warning lights, I think 57,000 miles.

I asked because it seems unusual that a spark plug wire related problem would cause stalling at idle but the car would run fine at higher speeds.

The rain factor compounds my confusion as is the fact that it will start right up afterwards. If it was spark plug wires, the high humidity when it's raining would most definitely make the problem worse, but as I said, I can't explain why it would run fine at high rpm and stall at idle.

Has the car been in a wreck of any kind? Could it have damage where the air intake is located? If it was mine, I'd be taking a good look at the entire air intake system right up to the throttle body. Look for signs of water.

The other thing going through my head is a failing MAF sensor (if it has one) and/or a MAT sensor of IAT sensor (if it has these). They could be affected by high humidity and their output is being skewed. Still within the parameters the computer is looking for, but enough to make it stall at idle.

Don't start replacing these things based on my thoughts. They are not much more than thoughts. This is all I can think of right now. I need to ponder this one a bit. Maybe someone else will have some ideas. I would not be surprised to find that this is a common problem.

 

[Squisher]

Another thing related to the spark is the coil(s).

Coils can make any one of a dozen different problems. It seems sometimes that no two coil problems are alike

 

[SagaLore]

I plan on replacing my spark plugs and wires regardless of what the problem ends up being. Its about time for that maintenance anyway, and with any luck it will fix the problem. Any recommendations on plugs?

 

[StageLeft]

Rain has screwed the ignition coils on my MPV before. Just the dampness took a mild problem and made it severe.

Try OEM plugs from the dealer.

 

[evident]

alternator getting wet?