Anyone else have issues with their Evo breaking up or stuttering in the rain? Getting into boost it gets progressively worse. Full throttle the car just breaks up and goes no where.

This has been a recurring issue for me that I have not been able to track down. I've tried searching over the last few months and haven't been able to find too much.

Car still has all of the factory plastic (undertray, wheel wells, etc). I still run the engine cover as well.

Hundreds of people run short ram intakes or open elements and don't have any issue. I don't see why my car would be the exception?

Any insight? I'm starting to think I'm getting water somewhere in the ignition system somewhere. Not sure where tho...

Mods
FMIC
Intake
Exhaust
BOV
3Port
Tune

 

I have this same issue. I found that my mass air flow sensor connector gets wet also the exhaust camshaft position sensor connector gets wet. Look there.

 

Gotta be the intake it's getting too wet and misting you. Do you have pictures of your engine bay or how your setup is?

 

Here is a current picture of my setup. Pretty standard?

 

that is funneling water right into your intake from the fender. In heavy front rain I don't see how that isn't soaking your air filter and making water pool in the bottom of the cone. I had a drop in Cosworth filter for my tune, never an issue in the rain, roughly same gains. Dunno, that's pretty wide open imo

 

check your spark. I had the same issue and it almost felt like complete misfires under boost, which was exactly what it was with no cel or codes. I pulled my plugs and found that cylinder 4 plug was all rusted up. Turns out water was seeping into the plug well through the coil pack. Swapped that plug and all was good again.

 

And here I thought I was the only one.


I have the exact same problem but it always happens whenever I'm not in boost for a very long time.


For example, my commute to work is 95% highway. After about 30-40 miles of cruising with the intake under vacuum, as soon as I tip into boost I get the exact symptoms you describe.


I have to repeatedly tip into boost many times until it clears out and I can beat on the car normally.


Otherwise if I drive spiritedly for the majority of the ride I never get the problem.

 

^if you are running rich and/or have too cold of a spark plug - the plugs may be fouling...


Inspect plugs after driving out of boost for a long period. Are the very sooty with soft black deposits?

 

From the fender? What??

This is definitely not the case. The intake has never been wet after driving through rain, and there has never been any water pooling anywhere.

There are thousands of evos that have their intake setup the same as I and have no issues. Water is getting somewhere else.

I've pulled cylinder 1 & 4 plugs before to inspect, but didn't notice anything weird. I just picked up a set of replacement plugs so we'll see once I swap them out. Out of curiosity, did you run the plastic engine cover?

 

Water getting into the intake/filter is definitely not the issue. I can guarantee that one.

 

No and that is the reason in my case. One day I took my engine cover off to clean off some spilt oil around the oil fill and left the engine cover behind the car. I completely forgot, backed up and shattered it into pieces.

 

I'm using the OEM DILKR8B6 and tuned for E85. AFR is stoich in closed loop while cruising.


The only thing I can think of is that I may need a hotter plug or tighten the plug gap with E85 since it burns cooler. I hardly have this issue when I use 93 but I haven't used that in months.

 

Drove through a rain storm a few days ago and no breaking up.

The few times I've noticed it it has been extremely humid. Could have just been a fluke. I'll check back next time something pops up.