1990 240 will not start after rainfall

This car will not start after rainfall. Engine cranks but will not
start. This has happened a few times this year, sometimes the car will
start the next day after the rain stops.

 

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
1980 and the car might have had a few less other potential things to go
wrong.

 

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.

 

Wiring harness

Well, there are a few more things that can be checked if what has already been said is not helping.

The wiring harness coming off of the distributor and wrapping around the motor eventually going through the fire wall is known for being faulty in 240s 1987 and older. These will usually have been replaced at around 70k miles, but if your car is from a warm climate may not have been replaced. You can usually tell because it will be wrapped in electrical tape instead of black harness shrink wrap.

Check the fuse on the rail next to the coil. check it again.

Spin your fuses inside the car, sometimes they can lose connection.

Loosen and tighten the ground strap from the block to the firewall

Make sure you have fuel to the fuel rail.

If your car fires (which in this specific case it isn't) try disconnecting the first injector wire. Now turn the car over... Often the car will fire up on three cylinders and then you can reconnect the injector wire and drive away.

Other things. Test the spark starting at the coil. Ground the coil to the frame and see if it sparks. If it does then attach the cable running to the cap and test the cap end of the cable. (If no spark, bad coil wire) if you do have spark, check the cap and rotor, any corrosion can cause it not to fire. Also hairline cracks that you can't see can cause it to arc all over and not fire. Check spark plugs for spark.

If you are still coming up short check the connection in the cable coming out of the computer (by the windshield wiper fluid reservoir) but DON'T nessecarily unplug the computer. There is often a connector in that wire down near the alternator unplug that one and clean the connections. (Some cars do not have this)


If this doesn't work then it is most likely your muffler bearings

 

Also, check the connection on the electronic control unit/module (ecu/ECM) it is located on the passenger side outside wall behind the plastic kick panel.

The only other options are of course trying to die from electric shock, which I have had to do on two different cars. Grab those wires! And hold on tight!

 

Probably have a leak in the windshield, Check the fuse relay under the passanger side. White square, replace for like 12.50. Same thing happend to wifes 240. Alot of times if there is a leak they get corroded.