1990 Volvo 240

Had some rain recently and this has only happened two days so far, hard rain all night, go to start my car day after, not necessarily still raining and go to start, barely starts, I’m talking 3-4 turns of the key with 8 seconds each time just to get it to start. Once it starts, horrible idle that evens-ish out, but the second the pedal is touched-it can barely get the rpms up and stalls half the time. Tried to drive it like this once and it stalled.

Anyways this morning this happened, same stuff. I don’t go anywhere and intermittently today I’d go outside to start the car as it got drier outside. About an hour ago I started it up and it’s fine everything is working perfectly. I do not want to get stuck because of the rain again, thank god this has happened on non-important days at my house.

I have two codes
ECU: 1-2-1
EKF: 2-1-4

 

A common cause of poor starting/bad running in the rain is tracking in/on the distributor cap or rotor button. The moist air allows arcing to take place in/on the cap/rotor, redirecting the spark to the wrong place. Once the arcing has happened, there will be tracks/ tracings that the spark will follow easier next time in the presence of moisture. The tracks are visible is you know what to look for -

An easy test is to use a spray bottle with water and spray on all the ignition parts, in a shaded environment - looking for arcing. (engine running)

 

And if I find an area where it’s arcing? Does that mean bad wiring or a bad part? What do my codes have to do with it?

 

If you find a little grey line running from a pole in the distributor cap down to the base where it's attached to the aluminum base - you have to replace the cap, you can't get rid of the "tracking" in the cap. Or in the rotor) And sure plug wires can arc to the valve cover if bad enough (that's where the spray test comes in handy)

Your two codes are for air mass meter signal and engine speed sensor. The engine speed sensor are known to fail.
I would check the engine speed sensor wiring - the insulation on the wiring to it tends to crack and fall off causing all sorts of problems. (poor running, no starts etc.) You can also check it's resistance with an ohmmeter - I've forgotten what the value is supposed be be - maybe less than 90 ohms? (anybody have that info?)

I trust you have a legend for those codes and erasure instructions, if not you can find that info here

https://www.volvoclub.org.uk/faq/Eng...agnosticCodesi

 

Gotcha, I will do this tonight while it’s dark to look for arcing, I’ll check the cap and the resistance on the other thing while it’s still light out, where do I check the resistance on that thing?