I see Art cured your problem. I was going to suggest the same solution, I'm just slow. The question of the CPS, is use the original Volvo one and keep the IPS as a spare in the toolbox. Your main pump sounds like all the others ,push on it a little and it changes tone. I've always gone by the saying, " if it ain't broke don't fix it" well except for the problematic fuel pump relay behind the glovebox. I always keep an extra of those. Only thing I'd do in the main pump is to keep the filter clean and changed every couple of years. And keep that flm trap cleaned out. Good luck, if you ever want to get rid of it just stand outside and shout, I'm probably close enuff I could hear you. Max

We have a couple of 89's, one a wagon, the other a 4-door.

The battery for ignition arrives at the coil on the blue wire. Like Chuck says, the blue wire originates at the ignition switch (circuit 15) and appears on the hot side of the fuse block. It does not get fused, but leaves the hot side into the wiring harness bundle going through the firewall to a connector close to the coil, here:



I've had the experience of repairing the connector for corrosion in two cars, strangely neither of them were our cars.

But until just this year I would have never suspected the wire itself could be a problem between that connector and the fuse panel. In our sedan, the tach stopped working. Some rodent, either mouse or squirrel, chewed into the harness where it passes under the left strut tower. Got the white/red wire, not the blue one next to it. Difference between tach not indicating and car not running depended on the rodent's choice of wire.
--
Art Benstein near Baltimore

“How much does a chimney cost?”

“Nothing, it’s on the house…” or "It's gone through the roof..."

12v at coil 15 comes from the ignition sw, through the fuse box, etc to the coil. you need a wiring diagram. the 25 amp fuse at the battery is the fuel injection only-never had ignition on it.