OK... I just bought a '92 740 wagon, 68k miles, one owner. Still has the Dave Ostrem Imports badge on the back of the car. Leather, crank roof, no cruise. All the other popular power options. It's basically a new car, for a 740. The interior is virtually perfect. And soon it's going to be a 940, once I switch badges ;)

But: I didn't look at the car carefully before I bought it. I had taken the car home a few times in fall when my car was in the alignment shop. It never sold for some dumb reason, so I finally made an offer that I thought was good and now it's mine. I didn't want another wagon, but with the miles and the condition, I couldn't pass it up. It was expensive, but cheaper than buying a new car. All in all, I'm still really happy about it.

The thing is, I never noticed it has Rex Regina system. I don't know a whole lot about this system except it's similar to a lot of other cars. It's in my dad's 940 as well, but I never dug into the EFI system.

Naturally the thing has puked on me three times since I've been driving it (not even 2 weeks). Last time was Friday night at the airport, at midnight. An inopportune time for a breakdown. I did everything and the thing would not start; no spark and consequently no fuel, although the fuel pump relay is good. In fact, all the relays click and deliver current. So I was down to the coil or the crank sensor. No codes. It would only not start when warm. If I let it cool, it would start. Classic crank sensor, relay, or coil problem.

While I was perusing the engine compartment, I noticed a black box on the firewall, about 6" square. I have no idea what it is. It's stamped "Volvo". But what, I have no idea. Ignition? EFI? What is this thing, mounted right behind the engine?

I finally ended up diagnosing the big coil pack as the cause of my problems. I had a spare lying around and it would start with the new coil pack and then not start with the old one. Problem found. Actually, if I had just read the "made in france" on the coil pack, I would've replaced it anyway out of suspicion. The one I took out had a different P/N than the Volvo one I put in. Whatever.

Also much to my disappointment, I saw a GM map sensor under a little plate on the strut tower brace. I'll have to get used to that.

My basic question other than the black mystery box on the firewall is, what's the deal with the basic system? Is it decent? I don't have green manuals on this system, that I know of. Is there a place in the 700/900 FAQ that I haven't found? I'm curious to know more about the system, although it's similar to some Jeep and other products. I just don't know what is doing what. I do know about the GM fuel pump, although taking out the 740 gas tank is a breeze; easier than fighting through the little hole in the floor or the trunk. So that's not a concern. I'm just wondering about the basic system, it's reliability, or any little nuances that I might not be aware of. I haven't seen a lot of problems with the system, which is why I haven't seen many cars in the shop with Rex Regina system problems. But I'd love to know whatever anyone can tell me.

One last question is, what are the 3 pressure or temperature sensors on the front of the condenser? This is still an R12 system, and I'm the A/C boy... as long as it's 134a. There's no auxiliary fan on this car either, but obviously it has an electric engine fan.

Any help or suggestions on these little details would be greatly appreciated.






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Chris Herbst
1992 745, 68k

And others:
93 944, 150k
90 245, 110k
88 744, 160k
87 245, 185k