A few weeks ago my 1994 850 Volvo started "missing’ momentarily losing power- check engine light coming on, then ran ok. One trip it happening 3 times in about one minute. The mechanics couldn’t find the problem. The next time I drove it, it shut down completely and wouldn’t start back up. After towing to the station, it started up immdeiately. I’m leery to drive it now until I can find out what’s wrong and fix it. Any ideas are appreciated. Thanks!
The mechanics MUST have read the stored computer trouble codes. Please let us know what they were.
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P1234) not just their translation into English and post it back here.
They found 131 indicating the engine speed signal. Replaced the crankshaft sensor, but that didn’t seem to help. The only other thing they could think of is to replace the main relay. Those are the 2 things they experienced go most wrong with those Volvos. Haven’t had the main relay replaced yet.
The OP’s car isn’t OBDII.
Relays can do that. They get thermally sensitive. An internal connection breaks open when they get hot. When it cools it re-connects Ignition modules can do that too. That would account for the missing.