For a while now my 245 has been running rough and I was quite certain that the fuel pump was not working and that the car was operating only on the tank pump. Is that even possible? On the highway I would notice that the engine would stutter for a moment and then kick back in and it just seemed anemic. Also, if I down shifted and put the car into neutral at speed it would stall or near stall, so I had to keep the pedal down to keep the engine running. With the car parked I listened for the main pump with the key in II and didn't hear any hum. I checked the fuse and jumped 4/6 and then heard the main pump hum. I'm going to replace the plugs/wires/cap/rotor to see if driveability improves - it's way overdo for these anyway. And I'll run the codes too. Any other ideas?

Remove 25 amp fuse to reset OBD.,this should eliminate the check engine light.If not check for codes.The service light can also be reset,you should have a "button" in the dash that you can depress several times.The oil light,check for a loose connection or chafing of the wire to ground under the engine.

It would be impossible for your car to be running on only the in tank pump.
--
1966 122s, 1968 142s, 1969 144s, 1979 245dl, 1989 244gl

That's what I thought, but I wasn't sure given I couldn't hear the main pump running. But maybe my hearing was off?

Clean the TB and IAC.Look for cracks in the accordian hose,a small flashlight in the hose[off the car] will show any pin holes.Good luck.

^This must be it. The TB was gunky and I cleaned it well - all the corners, brass fittings, etc. I removed the fresh air hose, and sure enough, there was a half inch slit on the under side. Is there a better quality aftermarket hose that I should use? Should I just order the replacement from Volvo? What can I do in the meantime to seal the hose so that the car is driveable?

Duct tape!

Ha ha! That's what I figured, but couldn't find any so I just wrapped it really well/tight with electrical tape and it seems to be holding fine. There was a cluster of pinholes near the large hole as well, so I taped the whole section.

As far as replacement goes, is a new OEM hose the way to go? What about some of these aftermarket silicone hoses? This plastic OEM hose seems pretty flimsy actually. Any better options out there?

SO the good news is the car fires up and runs with a much smoother idle after changing the plugs/wires/cap/rotor. The real test will be after a rain. The bad news is all the dash lights aren't coming on when I start the car. All but the ABS (this is a non-ABS car) used to come on during ignition. Now only the check engine/oil/and briefly the service light. The rest stay dark. I had disconnected the 1 coil wire per the Bentley manual as well as the battery. Did I miss something?

You accidentally disconnected the small red wire to the alternator or your alternator ground wire has an intermittent fault.

Both are common issues. In the case of the red wire, oil from oil filter changes, mis-routing, vibration and corrosion take their toll. It is usually a pretty visible fault.

The alternator ground wire can only be completely ruled out by removing it from the car and twisting/pulling the ring connectors on the ends, cleaning where they mount and reattaching to the alternator and cross member (I think...been a while).

Thanks for your responses guys. I think this must be it. I also had an oil change done yesterday, and it was a little sloppy. I probably also knocked the alternator wire when changing the plugs/wires. I'll have a look, but I bet that's it.
Thanks!

Your ignition component refresh is a good first step. Next, check your air: air filter, AMM, throttle body, vacuum leaks.

Definitely check OBD for codes.

Once you know that the ignition components are good and there are no serious air restrictions, you can start to diagnose a more serious problem.

Sounds like a plan. Thanks, and I'll report back.