Actually it’s a little more complicated…
If it’s cold and rainy out the car will start just fine, however if I drive it for just a short distance, say 2 miles or so and park it, it won’t start again till the next day.
This only happens when it’s cold and rainy and if I let it sit for a day it fires right up.
If I drive it for at least 15 minutes the problem doesn’t occur and it continues to drive normally.
I took it to a mechanic and he had no idea what was wrong.
Any ideas?
Mods - wasn’t sure if these type of threads go hear or GQ so feel free to move
Maybe you have a cracked distributor cap or it’s not sealed properly. When it rains, it wouldn’t get wet, protected by the hood of the car. Once you get moving and water is kicked up into the area, something is getting wet and killing it.
Could be a cracked wire casing somewhere possibly.
Starting problems in the rain makes me first think about bad spark plug wires, distributor rotor and cap, and maybe coil problems. This is if the engine is turning over. Possibly the driving in the rain is spraying water on the ignition system. Has the car ever been in a front end wreck? Or has some of the shields under the engine broken loose? That could leave water in.
Is the engine turning over, by the way? Not turning over and not starting when turning over could have much different causes.
Possibly the fuel injection is running richer than it should (excessive fuel) when the engine is cold. This could cause fuel fouling of the spark plugs, where they’re actually wet with gasoline. Sitting for a day would let them dry out. Running the engine until it’s fully warmed up would help evaporate any fuel on the plugs, and also likely gets the fuel injection to a point where it’s not delivering too much gas.
To check on this, I’d pull the spark plugs when the symptom occurs to see if they’re wet. If they are, the first thing I’d test is the engine temperature sensor. A false temp sensor reading could induce the computer to allow more fuel than is appropriate for the actual temperature.
Some fuel injection systems have a “clear flood” mode that disables the injection of fuel if the accelerator pedal is held fully to the floor while cranking. If this is the problem, and if your system has that feature, you may be able to start it by keeping the pedal floored until it starts.
This problem would be affected by the cold, but probably not by the rain. The ignition components mentioned by JerrySTL are the main items susceptible to wet weather, and if that’s going on the ignition spark may be weak. I’d test them by spraying water on them (when they’re dry, in the shop) to see if it had an effect.
Assuming it doesn’t act up when it’s cold and dry or when it’s warm and rainy, I would suspect you have a combination of both fuel injection and ignition issues causing the problem.
What is needed for the little explosion that drives the piston down is (1) air, (2) fuel, (3) an ignition source, and (4) compression. 1 and 2 need to be mixed in a proper air/fuel mixture of around 14-to-1 give or take. Ideally 3 (the spark) should happen when the piston is near the top of the cylinder which provided (4) compression.
As the engine does run at times, we probably can eliminate 1 and 4 as the problems. That leaves fuel and ignition. As rain is a factor, I’d look for ignition problems like bad spark plug wires, cap and rotor, or even ignition coil. Next time it happens, open the hood and have someone try to start the engine. If you hear any snapping sounds, it’s almost certainly ignition related.
If not ignition, it could be fuel. The next time it doesn’t start, you need to put a fuel pressure gauge on the system and see if the pressure and volume is right. That’s probably a job for a mechanic. You may need to take the car to a mechanic the next time environmental conditions are right.
What did that mechanic do to troubleshoot the problem? I’m thinking that you may want to try another wrench as a good mechanic would probably know how to troubleshoot such a problem. I’d be out the with a spray bottle of water on the ignition system myself.
If it is something really strange and difficult to isolate, you may want to go to a Volvo dealership. There might be a TSB (Technical Service Bulletin) on such problems. You’ll probably pay more, but it will probably be fixed faster.
Oh! Is the service engine light or check engine light on? If so that could be a major clue in the problem.
This sounds eerily similar to what happened to my Mom’s 98 S70 – difficult starts in wet/rainy conditions, sometimes leading to the engine cutting out. The mechanics replaced the plugs, the coils and the cap but we still had the problem. Some googling led to me to suspect the fuel pump relay was faulty, however the real problem was even more fundamental. What I discovered is that the fuel pump relay sits in a tray that would partially flood, causing an intermittent short. After digging a ton of muck and a deck screw (!) out of the plugged weep hole the car has started without a hitch ever since.
The relay is the red cube thing in the middle, the drainage assembly is to the left. Hope this helps!
