I have noticed that not too many 240 series people post problems about the power stage.

Though 700 series owners have lots of issues with it.

Here are my investigations:

240's starting in 89 (thus weeding outs lots of bricks already) started using EZ-116 ignition system, which incoporates RPM sensor on the flywheel. This systme also requires a power stage, a flat solid state piece in front of the batter right against the fender, which breaks the ground (terminal #1) to the coil. (according to Bentley)

I called Groton and the guy has no idea what it is, he has never heard of it. I was shocked. Maybe not many of these parts fail.

Lots of 700 series owner point to this as being a part that can fail intermittent (yes, as well as the FI relay), causing the car to stall out randomly at all speeds. Only to find the car starting right back up.

I called the IDP guys and he mentioned that these parts either burn out or work, being a solid state part.

I have been suffering from this type of intermittent failure and replaced so many parts (relay, pumps, 25 amp fuse, RPM sensor, throttle switch...) problem continues. I was curious if the problem was with the ECU, but I think that's rather unlikely, also I should start with cheaper parts first. ( My brick didn't have a tach, but I installed one yesterday, but problem hasn't resurfaced yet)

What are your thoughts? It seems quite number of people suffer from intermittent failures on these Volvo's.

Cheers,