Your '89 doesn't have an impulse sender on the distributor, so that's not a worry. But you do have the 25 amp fuse, fuse holder, and wiring in the coil/battery area. Those items are known suspects the older they are.

The Fuel (Injection) relay is also a known suspect. It's actually 2 relays in one case. The Fuel part is usually the culprit, and can be bypassed for testing by connecting a jumper wire between the Left side contacts of fuses 4 and 6.

This jumper also bypasses the 25 amp fuse, so it often can get a stalled car running. With secure alligator clip ends on the jumper wire you might even drive it like that (people have done it with a paper clip).

The RPM sender (aka crank position sender) is only $30 at FCP Groton, and is long overdue for replacement if it's the original.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

The impulse sender in the distributor messed me around for about six months once. Car would start and run fine but then just not start at the supermarket, causing a tow home. It would then start after a couple of hours and run fine.

Then it began to stall right in mid-flight. Let it sit for a half hour and it would start and run fine again.

Local mechanic found the snag by bringing a second distributor around to the car and hooking it up when it stalled a block away from his garage.

I think the impulse sender was reacting to heat from the engine and making and breaking contact.

Bob

I had the same problem with one of my 1984 244's ,however I'm not sure if the ignition systems are the same. On mine it turned out to be the pick-up in the distributor. Replaced it and no problems.

Good Luck.
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1984-244 GL with 192K and 1984-244 GL with 260K, 67 Mustang and 62 F- 250 4x4

Well, used fuel relay, $3-10, CPS from FCPGroton at $40 or so (and pretty easily self-installed) would be my first guesses and moves. What fuel injection relay? ECU is notorious in '89s but usually 561 as you know, and usually a full no-start condition. ECU failure is very common, but I do not think it is your problem at all.

in my service manuals from volvo/87 240 volvo warns that the ECU is the least suspected culprit, it's actually the very last thing on the list to check...the most likely things are ignition components/ air leaks in intake system such as loose broken hoses/ evap hoses , even the ones coming off gas tank (a problem that i had, that i never thought to check until i found a s shaped metal hose connecter hanging of the brake cable near the differential, this problem caused me months of aggravation and i didn't even know about it, so check all hoses and simple things, fuel injection components are designed for an extremely long life and hardly ever fail, i mean the do but my manuals say cheek them last.