[modain]

My 1999 RC 2.5L I4 has a peculiar problem. It won't start or run if the air is wet from any consistent amount of rain. Even sitting, not run, no leaks, etc. After a day or two of heavy rain the engine will not fire up and run. I might get some (mis)fires when cranking, but it will not start. If it ever does start, it will run very poorly, then die - never to start again until it has been warm and dry for days.

It would seem to be an ignition problem, and most likely the distributor is collecting moisture which condenses and fouls up the electronics in the distributor. Questions: 1) has anyone else had this trouble and what did you do? 2) would this be as simple as a cap replacement? 3) is there perhaps a seal missing on the cap or distributor that I should look for/verify?

Thanks!

 

[immattj]

I had an older 318 that I was doing some puddle jumping with and moisture got in the cap & caused a short between a couple of contacts which actually seemed to change which contact in the cap was firing which plug wire (i could switch a couple of wires and get it to run better). It didn't shut it down like yours, but I suppose the extra cylinders of a V-8 would make it more forgiving of losing a couple.

I don't know anything about the 2.5; does it have an ignition module of any kind? I am thinking not.

But sure, I think a cap (& might as well do the rotor & the cam position sensor while you have it off) would be a good affordable place to start throwing parts.

 

[immattj]

. . . after the game was over, I did a quick look on Rock auto at your year & engine, and no, I don't see anything out of the ordinary, such as some kind of module, under the 'ignition' section. Maybe the coil is some how getting permeated with moisture? I am not suggesting that you throw a coil at it.

Something you could do, next time it is in this condition, is check for spark from the coil, se if you can carefully identify a good strong arc from the coil, and if you are getting that I guess you would have to figure it was something between the spark plugs and the coil. So I am kind of thinking while I am typing, and maybe if your plug wire insulation is old and nasty and worn out the high humidity in their environment is affecting them?

 

[modain]

Hey thanks for your suggestions. I fixed it today. The coil was giving good spark, so that didn't seem to be the trouble. When I pulled off the cap I discovered the terminal posts were pitted and corroded. The center pole was nearly flat with the bottom side of the cap. I don't know how long they have been on, but I do remember changing them a few years back. Maybe ten, but in that time maybe about 10K miles have been put on it? The wires are good at the connectors - no corrosion.

Anyway, with a new cap and rotor it fires right up. Just like it should. $21 fix. I like that! I'll have to give it a spin in the rain just to verify all is well.

 

[immattj]

Thanks for the update. That's interesting, you wouldn't think the contacts in the cap would be that wiped out in 10k. If you don't know when they were last changed, it might not be a bad idea to get the rotor & cam position sensor (aka distributor pickup coil) which also live under the cap. They are both what I would consider tune up parts.