What the hell.....!?

[a-soares]

I there, I have a 96 Polo with a AEX Engine fitted. The proble i'm facing it's so strange i'm looking for some help trying to find out what is wrong.
It fires up OK and apears to work fine for about 5-7 minutes or so of normal driving. After reaching the normal working temperature it starts to misfire and turn the ride into a rapid sequence of pulls and pushs. After some time (about 30 minutes or so) it returns to normal again and stays that way for as long has the ride may take.
This first apeared last winter after a VERY HEAVY rain.
What the ..... could be the problem? any ideas from anyone?
The problem desapeard in the summer but returned with the first winter rains.
What i've already done with no success:
I've already checked the connections and none seems to be loose.
I've checked if the ECU is not loose and the cable is well attached (but i didn't took it out to see if there's any pin corrosion)
I've took the distributor apart and cleaned all the connections
I've replaced the spark plugs
I've check all the wires, but i'm not shure what sensors are connect were (a schematic would be apreciated...anyone?)
I've already pulled some hair off my head
:confused::confused::confused:

[zukgod1]

Wow, sounds like you have touched most if not all the ordinary bases already.

Have you replaced the disty cap? I know you said you cleaned the connections already.

How big of a rain storm are we talking about here? Massive down pore or just a slight drizzle?

[a-soares]

It was a massive pourdown.
I've talked to a friend who is a mechanic and he told me that the simptoms my car is showing are usualy due to a defective injector-the most usual is a car start ok and becomes terrible when hot.
I'll try to take them off and see if they're blocked by any dirt. They may have some problems wth the return spring or something like that besides the dirt problem. Other problem that may arise is contamination of the fuel with water that causes rust problems in the injectors. Let's see... They do wear out... (car has 180.000km)
At least i have a possible cause for this strange behaviour.
If the probles is due to the injectors i'll put a post to alert anyone about the simptoms from bad injectors.
Thanks for the help

[zukgod1]

That a possibility I suppose.

Before you tear it down try running some SeaFoam though the tank. That will eliminate any dirt but wont take care of a truly bad injector.
180k isn't really that many miles really when it comes to a gasser injector but stranger things have happened.