What a car!
I bought this 1989 740 Turbo as a cheap project to fix up. I am planning to use it as a road trip car. My daily car is an 850 T-5.
The big problem it had was intermittent stalling when warmed up. Brickboard.com resources (especially the 700/900FAQ) suggested a possible bad Hall sensor connection in the distributor. Boy, was it bad! The previous owner or his mechanic did a crap job of repairing the broken Hall sensor plastic insulator with some kind of high temp epoxy. I ordered a replacement refurbed Bosch complete unit with new rotor and cap, and fitted it myself. Put in new ignition module and fuel injector relay just to be safe. Changed plugs at the same time. The car now runs perfect with no stalling.
The OD relay worked intermittently. I fixed it by removing the circuit board from the plastic housing, and resoldered the apparently OK looking solder joints connecting the brass pins. OD worked perfectly after that. (I got clued into the problem being bad solder joints when I rocked the OD relay forwards and backwards to see if it made a difference to the OD light appearing on the dash, and it did)
Replaced the old cat converter with a $100 Magnaflow (thought it was a choked cat causing the stall).
Given that I hadn't driven this car for 6 months and have left it parked by the side of the road for all six, and only starting it up intermittently, it's amazing how well the thing is running now. I don't think the previous owner showed much love to it in terms of maintenance. I have replaced most of the important fluids. Doing an Auto-RX (http://www.auto-rx.com) cleaning cycle in the oil at the moment, and on the transmission soon.
On the road:
This car picks up speed very unnoticeably. It's a fairly smooth pickup to 80km/h. Does freeway speeds of 110km/h quite easily, though given the boxy and less aerodynamic shape, it slows down very easily when you remove your foot from the accelerator. Good low end torque. Climbs hills well.
The only complaint is that, because the AW71 auto trans has probably not been well taken care of, it takes a while to get out of 1st and at fairly high RPM. And then it shifts hard. I have read that this does not mean that the trans is going to die soon, but is pretty normal for an old 740 like this one. I will be Auto-RXing the trans soon to see if it will make shifts better.
Volvo (s**t) box (that's what some of the younger generation call them 240s/740s here) drivers get no respect on Aussie roads. So it's quite funny when you can sense that other drivers in modern cars think it's a slow fuddy-duddy car, and keeping pressuring you to drive faster by tailgating you. And then you just take off and leave them in your wake!
Given that the springs, bushings and dampers are really old, it's surprising how well the car soaks up the aberrations on our bad Sydney roads. Turn in is pretty damn good for an old car. The high-driving position is excellent, as is the ground clearance. This car has better supporting seats than my 1994 850T-5 (!).
1. Fix the intermittent dash lighting.
2. Replace all cooling system hoses and that silly plastic heater valve.
3. Replace brake rotors and pads.
4. All belts and seals to be changed.
5. Converting from two fuel pumps to one high pressure in-tank Walbro pump.
6. Installing new used wheels (paid just AU$250 for a set of 4 with 80% threaded Toyo sport tyres)
7. Will modify stock airbox to let it suck in more cold air, freely.
8. Will see if I can install cruise control.
Used parts are cheap and plenty, especially on Ebay. I have bought my new parts from http://FCPgroton.com. Even with the shipping, it's much cheaper than any other source I have found locally.
I love this car. With the numerous Volvo resources on the net, it's easy to fix most faults yourself.
It only still has less than 200K km on the clock. Will surely up the mileage taking it to Perth and back some time this year!!!