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1110 Views 20 Replies 14 Participants Last post by  Z63R
I noticed this when I go through a drive through car wash, when I leave, my d23 stumbles a few times, like the plug wires or somthing is getting wet, after a few minutes, its ok, ok, fast foward, today is the firs time ive driven in the heavey rain with my cai, and it did the same thing in 5th at about 55mph, stumbled. I popped the hood as soon as i could pull over, the MAF is dry, (connector), and the entire engine is dry. Could this be my traction control kicking on and off when the tires are wet (hopfully), As soon as I thought about it, I turned it off. If the filter is getting wet, it would take ALOT of suction to suck water up the filter, tubing, and to the maf or tb, i would think. Anyone else having these problems.
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Anyone else having these problems.
I have had the same problem on my ’03 2.3L. I initially thought it was from rain and my CAI. But after cleaning the top of my valve cover one hot dry day it stumbled the same way. So my guess is its coming from the coil packs, knock sensor, or the wiring harness in that area. If I barely give it gas it won’t do it, but too much throttle and it does.
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I will feel 100x better if more people chime in and have had this. The first time this happened, its only did it on 2-3 occasions, I just knew I sucked in water from the carwash somehow. I was thinking how I could put a new engine in my car when its so new.
This has happened to my 2.0 since the day I bought it, more often when newer then now... It still does it here and there, but not nearly as much. I don't believe water has anything to do with it, not in my case at least.
I recall reading on a Formula SCCA web forum ( ) that there was a problem with the spark plug terminal ends not making good contact with the top of the spark plugs thus causing a mis-fire. The Formula SCCA open-wheel and sports bodied race cars use the stock Mazda 2.3 Duratec engine.

This issue was adressed about a year ago so a person might have do do a little research. This may or may not be the cause of your problem.

Gerry Dedonis
Kansas Engines
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can I bring this in under warranty, or will they frown at this being a symptom of my CAI?
Remove the CAI and put the stock intake back on.
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Ok this is what happens to me. If I start my car up for beig turned off for a long time and I slam on the gas to rev it, it will bog down and then idle or when I slowly start moving and slam on the gas same thing. So it's like when it's warmed up then it's all good. As far as doing anything weird in the rain not yet for me.

Nobody has really changed their spark plug wires because they think it wouldn't make a big difference, but what if they are wrong? I would certainly try it if anything it's just gonna make the engine <---> bit more efficient.
You can give it a whirl, but we don't have spark plug wires.
like he said, we don't have spark plug wires.

we have what's known as coil-on-plug ignition. There is a coil that sits on each spark plug. That means we have no plug wires. Coil on plug is the best ignition setup around, hands down.
i've heard the term coil packs more than coil-on-plug ignition which is right either way. i know that they are totally the way to go if you plan on boosting or putting any real strain on the engine, i really dont' know why ford didn't start with that on the zetecs.
Coil-on-plug is the type of ignition our cars have. Coil packs are the actual assemblies that sit above each spark plug.

To clarify the above, we do have wires leading to the coil packs. However, they aren't nearly as important as plug wires in a vehicle with a distributor. They also can't slowly go bad, or be replaced with higher-performance wires. They either work at 100% or they don't work at all.
OMG whatever coilpacks, spark plug wires, you say tomatoe I say tomato. [censored] it I'll get the Nology COILPACKS soon and see if it helps.

Nology doesn't make coil packs. All they make is a retarded conversion kit so that you can put huge spark plug wires on it. It moves your stock coils down out of sight and uses thick red plug wires to carry the spark from the stock coils up to the spark plugs. If you think that's a performance benefit, I have an APC factory in Arizona to sell you with an awesome oceanfront view.
LOL point taken. Well that is so lame about it being a conversion.
when I had my longtube cold air intake I had stumbling problems everytime I went to a carwash or when it was raining just driving down the road, regardless if I was in a puddle or not.......I would get rid of your cold air intake and go w/something that still brings in cold air but doesn't have the filter sit at the bottom of your a volant, pipercross viper, won't feel anymore stumbling if you did that......
I have the same problem, and this is my diagnosis.

Yes, it's water related (after car washes), It seem's that it is water (now in mist form after being sucked through the wet filter under high acceleration) getting on the MAF sensor, temporarily giving the car a case of the hic-ups. It's not hydrolock volumes of H20, just the sensor not being able to read for a second, and cuting off the fuel/ignition till it can get a new reading.

Yes, removing your CAI would solve the problem. Or you can just not drive WOT for a few minutes till it dries out.
the MAF sensor voltage is simply the amount of current required to keep the wire at a set temp. more air (cooler than the wire) cools the wire faster and a higher current is required to heat it, making the car think there's more air moving into the engine.

now, say air (not that dense) cools it fairly well. if you spray water (generally cooler than ambient air in most conditions) that is much cooler and more dense (way more cooling power) hits the wire. the car thinks it got a huge burst of air and it richens it up to compensate, causing a stumble.
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