Car won't start after even the slightest rain.

[Mr. Schwarz]

So Ive searched around off and on on just about every E30 site there is, and I still haven't found a solution.

This is my dilemma. Car in question: 1989 325i M20B25

The car will run excellent, tons of power, gets decent mileage blah blah. If it so much as fogs in the mornings, my car will not start. Rain, forget about it.

I do have a hard time starting the car ever since I've owned it. Lumpy idle, long starts, some intermittent hesitations. Ive tracked down the vacuum leaks and fixed many of them, now all i need is a silicone boot and ill be set. Ive also changed the CPS, AFM (brand new) and cone filter, new spark plug wires, new spark plugs.

So my question is, what would become wet that could keep my car from getting spark?

[noneya54321]

Are there a check engine light, either during start up or when acting up. I'd defiantly try the intake boot. also check the connections to the CPS sensor. But also check the distributor cap I also live in Nashville area if you need any help let me know.

[Gregs///M]

Also check that the TPS is adjusted correctly. Throttle position sensor. This sensor is connected to the throttle body. It sells the ECM when the vehicle is at idle or when it is at full throttle.

Check the bentley manual for the testing and adjusting procedure.

Also make sure to check the condition of the engine to chassis ground cable. it runs from the oil pan to the frame rail on the drivers side. This cable must be corrosion free, and secured tightly. It closes the electrical ground loop for all the engine electronics including the starter.

[Mr. Schwarz]

You might be on to something Greg. My chassis ground looks to be burnt and quite old/worn out.

Ill also check the Bentley for the tps adjustment.

Do you think water/moisture on the ground would cause it to lose spark?

[Mr. Schwarz]

There is no check engine lights at all. And I have cleaned the connections and put dielectric grease on the prongs after cleaning them.

[noneya54321]

but have you checked the actual rotor cap and button the littlest moisture in that will cause problems. It may just have a small crack.

[Mr. Schwarz]

I have. Not a drip drop. The gasket is good. It started this morning after our heavy rain last night... Hmm. This has been a tough one to track down.

[noneya54321]

I just had a problem the past couple of days with the round plug under the intake. it powers the fuel injectors i unplugged it and took a wire brush to the contacts and my car is flawless again. I got an extra ecu if you wanna try it. Just gotta keep trying things.

[Mr. Schwarz]

Hmm. I might have to do that. Can't hurt. I also have another ecu. I appreciate the offer. Ill try both of those.

[Mr. Schwarz]

I replaced my cps because of this problem, unfortunately it hasn't fixed the problem, but when it does start, it runs damn good.

[Ceeker]

check the trigger wire to the starter. it's only hot(has power) when you turn on the ignition. also check all your starter wires.

[Mr. Schwarz]

The car will crank and turn over, but won't fire because of the absence of spark. I'm loosing spark somewhere when something gets wet.

[Mr. Schwarz]

The car is currently not starting and sitting in the driveway until whatever is doin this dries out.

Everything works when it's dry, but something gets wet and cuts my spark. It's not like my hood is open in the rain. This is depressing.