b18c1 swap in a 97 civic. Everything on this motor is mint. regular maintenance, swap was done by the book, etc. So...only when it rains really heavy...the motor will start stuttering really bad at low rpms, even if i down shift it will eventually start to lose power and next thing you know the car is sputtering and jumping and then...nothing. It wont start for a few minutes and then when it finally does it is still all jumpy and stutters. I had a 93 hatch with stock motor and it did the EXACT same thing! i have seen a few threads here and there on this, it seems like a common thing...what the hell is causing this? It almost happened to me today but luckily i got through the rain, i pulled over and popped the hood, nothing was really that wet. Air filter was dry, grounds were dry, i have a msd blaster but i put a plastic baggy over it and zip tied it to keep it dry, what the hell is going on! uhg!

 

usually it's water in the dizzy...

 

If you don't find a cracked dist cap or you replace the cap and it continues to happen, bad spark plug wires can also cause this problem.

 

Yea Wat he said up there and after do a tune up to be safe

 

my guess is the wires get some good wires that have a good seal

 

talked to honda service they said its moisture seeping into dizzy cap or something. i got new ngk wires and plugs, i looked at the cap and i can definitely see a small seem where moisture could be an issue when heavy rain, next question is do they make something to combat this? distro cap gasket? such thing?

 

You don't need anything special to fix this.

Personally, I would replace the distributor cap/rotor 1st. If the problem goes away, you are done. If the distributor cap is good, moisture shouldn't be an issue. You don't need a gasket or anything.

FYI, when replacing the cap, I always replace the rotor as well. If the cap has been on there long enough to cause a problem, the rotor is likely worn as well. Might still work but always a good practice to replace the cap/rotor together. If the problem persists after you've changed the cap/rotor, then replace your plug wires. This may not solve your problem but I've resolved issues similar to this lots of times over the years by doing this. Good luck!

 

you can always take a squirt bottle and spray the wires and dizzy cap. with water of course

 

Cap and rotors asap, cheap way to find out.

You don't have a hood with a scoop or say Evo style with vents do you? That can let water near the dizzy.

 

no hood scoops, the splash guards are there but not the best. what bothers me still about it all is that when it rains and i pop the hood after, everything looks and feels dry...its madness!

 

Don't forget about humidity, moisture etc, damp days all can affect it.

 

That happened to me on the way home from work, there was no water in the throttle body but in the distributer it looked like the inside was sweating. Once I cleaned the water out it started up like nothing happened...thank goodness it started, cause I didn't have any money for a tow truck.