Hoping some folks can help with some intermittent problems with an old warhorse manual 240 wagon with 416,000 miles on it. I got back from a year working abroad about a month ago, and some problems have emerged recently. While I was gone, the car was stored outside in rainy Seattle, with my brother starting it up every few weeks, and letting it run, but not driving it.

The car now has some difficulty starting up unless I give it a little gas, whereupon it idles a bit roughly but sounds better at driving speeds. On a couple occasions, when attempting to accelerate onto the highway, the car hesitates, or does not respond to pressure on the gas pedal and fails to accelerate, but this is not the norm. Once, stopped on a hill, there was no power when I shifted into first and the car stalled out. Upon subsequent startup there was power and was able to get moving again.

Recently the check engine light came on as well. Using the OBD probe I got the 1-1-1 code for the ignition system, meaning it's ok, but when I test the fuel system the LED just stays on. I followed the prescribed method of putting the probe in the correct hole, turning key to position 2, and pressing the button for 2 seconds, but then the LED just stays on. Doesn't show me any codes. Any ideas on what could be causing this, or how I can find out what the error code is?

I've tried some simple things like change the heater vacuum valve (could hear it leaking on acceleration), and spark plugs, but wasn't sure what the next step should be. I did notice that one spark plug wire is a bit loose in its connection to the plug. Doesn't snap on like the others. Could this have anything to do with its intermittent problems?

Any help would be much appreciated. I'm planning to do the fuel filter and some other simple things like a new flametrap, but I'd like to figure out what my next move should be before I move into more difficult territory.