2001 volkswagen golf runs rough after and during rain

very common problem with your year model is missing inner fender not sure why but if one is missing good chance when it rains u are soaking the coil causeing it to arch and miss fire or arching at connection at the plugs and wires if ur missing a inner fender dont waste ur time replaceing plugs, wires, or coil tell u have replaced the inner fender

replace the spark plug wires

Same problem as some of the vw golf and vw jetta cars. Water runs from the wind screen down that small holes in the bonnet. Somewhere there is a fuse box or computer box that gets wet. Seal that box with denso tape or cover it with plastic that you replace every 3 months or the dealer of the car can help you seal it. Be strong.

condensation getting into the rotor button via distributor,if a distributorless engine then condensation on the coil packs.

Did you use electric grease on these parts, the plug wires,and coil pack need this grease on there. It prevents moisture and wetness from rain getting within the components and causing mis-fire. Did it rain or was it cold outside to produce moisture. Grease is $2 for small pack. I just worked on a 95 VW, changed the cap,rotor button, spark plugs, cleaned throttle body, new air filter, fuel filter. His would run fine, but would cut off sometimes up to hours until the moisture dried. After tuning it up, he no longer has the problem. He goes through water puddles to see if it will quit, but it hasn't yet. Worth a $2-$3 try.

Water is probably leaking onto your engine somehow and shorting out the plugs.

Sounds like you need new wires and or cap and rotor, had the same problem on my jetta 1.8L when I would drive it in heavy rain it would bog down and misfire. The water blows threw the rad right onto your distributor and wires causing the short (old and cracked or just defective). Try it out I'm sure that will fix it.

ok laker1761,

I would start with this: if its only happening when the engine is getting wet get a hair spray bottle, or any bottle and spray water on the engine when it is running to get it to act up. A blinking check engine light means you have a misfire, it most likely has something to do with your ignition.

The two most common things ive see when ive performed this test, was spark plug wire, or one of the coils. What you will be looking for is to see if the spark is arcing from one thing to another, like a wire, coil, something. I would start their, that is the quickest and easiest step to see you have a arcing spark.

If it has a distributor cap, check for moisture inside when it is raining.

thats the risk you run when you have a third party not liscensed by volkswagen mess with your ECM. take it to the tuning shop that did the remap work and ask them to redo it because it messed your engine up, if you make a big enough stink they might do it for free.