Hi there. I have a 1992 Ford Tempo 4 dr GL. It has about 146,000 kms on it.

Anyways..recently I've been having problems with keeping the vehicle running during the rain. It's quite annoying. I will describe to the best of my ability what exactly happens here.

Firstly let me say that the problem comes and goes but has an absolute correlation with the weather. When it's sunny or even overcast the car runs fine, however when it is raining or just finished raining the car has issues.

What happens, is that when it is raining or has just finished raining, the car will start but will not idle properly. It runs really rough. My car idles at about 764 rpm but in the rain it varies wildly. I will hold the gas pedal steady at about 1000 rpm and even with my foot steady the revs still oscillate between about 800-1200 rpm. While this is going on the car shakes madly and will often stall, requiring restart.

Once on the road, the engine propels in fits and starts and does not accelerate evenly even with the pedal being held steady almost as if not enough fuel is getting to the engine. However, I'm sure this actually is not the case because the car works fine when the weather is sunny.

My best guess is that this is some type of wiring problem, because if it was a fuel line problem it doesn't seem to make sense that it only occurs in the rain.

 

So....I did some work on the car today...I really don't know what the problem is but I will eliminate possibilities one by one until I either find the problem or can afford to have a mechanic figure it out for me.

I disassembled the windshield water drainage system, i.e. that black plastic bit where the wiper stocks are. I unscrewed the black plastic bits but couldn't figure out how to get the windshield wiper arms (the arms not the wipers) (I'm not that dumb...lol) off. So instead I went under the hood and removed the black foam rubber bit that covers all that drainage stuff. The drain holes for the windshield water seemed okay on the upper part.

On the passenger side of the car, there appeared to be a drain with what looked like to me, a bizarre design.
Instead of lets say sloping the metal slightly so that the water ran through the drain, the drain (if it was a drain) had the metal around it raised by about two inches, and it had two covers to prevent larger crap from falling in, and at the bottom the last "filter" was a sponge.

I was tempted to pour water onto the sponge to see how well it drained but then I thought I don't really know with 100% accuracy whether this is actually a drain or not, and if it's not, pouring water down there might either create a new problem or make the existing one worse.
Does anyone know if this is indeed a drain or not. The location of said "drain" is on the passenger side, underneath a black foam thingy at the top of the hood (ie the end of the hood furthest from the bumper and closest to the passenger seat)

I should have taken photos, I didn't think about that though at the time.

Anyways, there seemed to be no obvious drainage problems from the windshield which I thought might be getting into some wiring.

Assuming this is a drain I can test the drain out, though I will just remove the foam bit and leave the black plastic exterior pieces in place (it's not necessary to remove them to access this piece)

So....yeah...no obvious windshield/roof water running onto wires around the top of the hood as far as I can tell.

Also for the record since this caused me no shortage of grief today, how does one remove the wiper arms??