Hello, I’d be super thankful if anyone could help me figure out this problem that I’ve been working on…. The car is a 1984 244 four-cylinder

I bought a Volvo a while ago, and I had some big issues with idling sounded like it was misfiring, and would occasionally stall out.

I replaced the ECU with one I found out the junkyard it was a few years older, but I put the ECU in and it started fine and was idling smooth for the first time since I bought it. However, whenever I tryed to drive forward, it would lose our power install out.

I then bought an ECU from the same exact year with all the same numbers on it. I think the numbers at the end are 510. I put this new ECU in and now it will not start with either of the old ECUs either.

 

What years did these ECUs come from? (I trust you are talking about your fuel system computer mounted next to the passengers right foot)

Can't answer your question exactly - but I remember back in those days when one of my techs would mistakenly try a 1985 Air mass meter on a 1984 car (trying to diagnose by swapping parts ) - Something bad would get fried, it was either the ECU or the air mass meter - So if you tried an incompatible ECU you may have fried it or your air mass meter.

 

The first ECU I got was off of an 86 but it started and would run idle fine until I changed it to an 84 the same year of my car is it possible that It would still fry with the 86 but only found out when I switched it? And yes, I’m talking about fuel system at the foot of the passenger side door

either way, thank you and I will try to test the air mass meter or see if I can get a replacement (I’ll make sure it’s the same year this time) with the correct ECU in the same year as my car

 

83, 84 used an aluminum air mass meter - and is not compatible with the black plastic 85 to maybe 1988 air mass meter. 1989 changed again (in the 240) to a different air mass meter.