Mazda 323 Hard Start in Rain or when wet fix
 

I have a 1999 Mazda 323 1.3lt BJ SOHC (approx 175,000 miles) and it has been very difficult to start after heavy rain or in damp weather.

Initially I repaced the fuel filter (type: under back seat), Spark plugs, Spark plug leads, air filter and intake air temperature sensor/air flow sensor as well as cleaning the throttle body with carb cleaner and none of these worked.

Symptems are: difficult start, low revs for the first mile of driving and max speed of 25-30mph. If it cuts out after initial sluggish start it is even more difficult to start the second time around. After 1 mile when engine warms up, it kicks in and back to full revs. Moisture must be evaporating when it heats up.

A friend of mine watched the car taking off after heavy rain and said he saw white smoke from exhaust and it had a rich fuel smell. It mustnt be getting spark, seems like the cylinders are only firing intermittently.

So the next thing i changed was the distributor cap, only cost about 28euro.
To get at it you just need to remove the air filter housing and then two 8mm bolts to remove the distributor cap.
The distributor cap was covered in white dust, the carbon brush in the centre was worn away to nothing and the 4 contact points were very worn and covered in white dust (images attached).

After a month of rain and hard starts each morning I fit the new cap and had to wait 2 weeks for another wet day (a very dry spell in Ireland for a change!).
Today was the first wet day since i changed the distributor cap and the car has started with no problem. I recon moisture was getting into the cap some how and maybe with a combination of that and the worn distributor carbon brush and contacts that was causing the issue.

Hope this helps someone else.

Bob

I've been having similar problems. I've been suspecting the distributor cap, but now I know what to check first. :-)

Get a Spark Tester. Moisture in the air maybe showing up a dying or weak ignition coil.

I'll see later.
The ignition switch circus has pretty much robbed me a Christmas.
I just got it to work right.
Couldn't shop for nice Christmas food (had to walk to the nearest shop), Couldn't visit my parents, couldn't even take some candles to my wife's grave.

Now that I got the darn thing to work, I won't touch it at least for a month.
(Sorry if I sound like I was a bit bitter, but I am.)