1990 240 will not start after rainfall

Distributor leads were causing difficult start and poor cold running in mine when it rained.

Thanks for that suggestion JG. Tomorrow morning I will try a new set of wires and see if that helps. I just went outside to try again (its still raining) and still no start.

Might be worth checking the resistance first, mine were probably original

Get the car somewhere dark (pitch black) and crank it. You may be able to see arcing along the wires. You can wet your hand and run it along the wires, but it feels real bad, and be careful that you don't jerk your hand into the fan or some sharp object. You want to be able to still count to 21 when you are done.

Take a spare spark plug and pull one wire at a time and connect it to the plug. Be sure it is grounded, and crank it to check for spark.

Also open the distributor cap and look for corrosion, carbon tracking or signs of oil, moisture, etc. Ecamine the carbon center contact and the rotor as well.

Pull the plug wires where they connect to the cap and look in the twers for corrosion, and examine the connectors on the wires the same way. Also check the same on the coil.

Examine the coil connections. It is not a bad idea to remove them all, clean them with Scotchbrite, apply a little silicone dielectric grease and reassemble. Use same on both ends of the plug wires as well. it also makes it easier to get the wires off the plugs later.

New spark plugs may also be in order.

Check the connection on the ignition module. Remove, clean, grease, reattach.

But it's probably the wheelbase.... ;-)

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Thanks Randy G..I am extremely adept at doing just about everything on this, my 3rd 240 Volvo (started with a 1979 240 wagon), from engine rebuild to electrical troubleshooting, but this problem has me beaten. So far I have changed the main relay, changed fuel filter and pressure regulator and fuel pump check valve. I will follow you instructions and hope that either yuors or JG's suggested fix will solve this wet weather intermittent problem.

The easiest thing is to spray the distributer and all HT leads with a water repellent such as WD40.

Used to get my old Ford Escort going every time in wet weather.

- Matthew

........... ha ha ha, you mean with all your good and helpful ideas RG, you don't have a way/s of avoiding ht lead pain? I don't either, except to abstain... But your "precautions" are classic :-) A mechanic told me it can kill a pig.

Well, the problem occurring in the wet does suggest an electrical problem. I'd check the spark plug wires, coil wire, coil and distributor cap. Probably the likeliest scenario is voltage leakage from one or more of the wires (especially the coil wire, if it plain won't start or doesn't even try to catch). Use some dielectric grease on the connections. Another possibility is the spontaneous composting of the wiring harness under the hood, given the age of the car.

The wiring breakdown was from the early 80's vintage 240s. I haven't read that it is found on later models, although wiring faults can occur from other sources.

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Based on that, next time it does not start, pull a plug and see if it is wet with fuel. That should narrow it down. ALso try a voltage check at the battery when cranking, and maybe even a voltage check a thte ignition module and coil when cranking. I once traced a no start fault on a VW when the ignition switche supplied voltage to the coil when in the "on" position, but it did not supply voltage in the "start" [osition although it did crank the motor just fine. if you got the motor spinning then released the key it would sometimes start.

As you stated that it only happens in the wet, it would certainly lead to an electrical problem. BUT.. is it ignition electrical or is it fuel electrical? Maybe a cam position sensor wiring problem...?

Compression Fuel mixture Timing Ignition

It's gotta be one of those! ;-)

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

But the WD-40 draws dirt which will hold more water over time and in the long term make the problem worse. Best to fix what is wrong, but in an 'emergency' the moisture repellant property of WD-40 can work.

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

A standard Kettering system puts out about 9,000-12,000 volts, but the amperage is VERY low, so not life threatening unless you apply it directly to the heart tissue or to the chest for a prolonged period of time. A electronix high energy system can put out 50,000 volts and that can be quite painful. I had a Delta Mark 10 CDI system on a car, and it would throw a hot, blue spark a full 3/4". It was so hot that the instructions said to WIDEN the plug gap in the winter for easier starting!

__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Checking the resistance won't do much good, it's insulation breakdown that's usually the cause of rain problems when spark cables are the culprit. They arc to the engine block rather than delivering the power to the plugs.

If you can, first try a blow dryer on the distributor. If the car then starts, you know that the problem is there. And it could be the distributor cap, especially if it is dirty or has a crack.

If you'd rather test it in the dry, fill an old spray bottle with water and mist the ignition parts qhile the engine is running. When you hit the sweet spot it will either stumble or stop. Beesides you don't have to suffer the sting of success when you find the leaky wire. :)

Bob

I'd bet on a bad coil. One went on my son's 1990 740. If it's the same design in the 240 (an open steel core with encapsulated windings), it's a design that's very subject to moisture absorbtion if it's wet/damp if any cracks develop in the encapsulation (and at possibly 15 years old, yours likely has them). Any dampess will result in a weak or no spark condition. You might be able to confirm this by drying out the coil with a hair dryer. Since it's an all or nothing situation when wet, that would tend to rule out individual plug leads (would more likely have a repetitive miss or rough running from that condition.)

I once had a 1970 Austin America with Lucas ignition components. Same problem as yours - would sometimes not even run on a FOGGY day. Finally I ran into a sudden thunderstorm downpour on I-95 near the CT/RI line. Car just up and quit. Fortunately, there was (and still is) a truck stop just down the embankment from where I ended up on the shoulder. Got a new ignition coil there and the car ran fine afterward.