Hi Dave,

Thanks for the run down on Volvos engine history that took place after and during the purchases of my fleet of used 240s.
With you talking about the horsepower racing it helped explain Volvo’s advertising with phrases like “blowing the doors off V8’s.”
I’m remembering that terminology only because I didn’t know anything about several smaller valves replacing one or two, large turbocharging, supercharging or some inter-cooling buzz.
It was truly a mixed bag of models competing on the global stage.

When it comes around to variable valve timing and the driving of those components are still putting engine in the grave yards long before reaching appreciable mileages of the 240s.

It appeared to me they (the industry) wanted engines to wear out with the bodies that rusted in America.
I don’t know if Volvo kept up with body undercarriage coatings later either?
I don’t believe the American domestics ever got any as it was truly an item a person had to purchase here from dealerships or body shops.

I’m glad to see the poster has given you some credit at being as close to an expert as one can get.
The word experiences put you in the realms of an expert and being to express those findings in your posts has given you lots of credibility.
Art Benstein is one in my arena and you have a blend of the whole Volvo line from what is see in that last post.
Both of you have blended your observations of the things you have dissected and concluded to be an accurate validation of Volvo’s evolutions.

As far as this thread goes, it seems he does have a bit of TLC to do.
The whole idle working and then not, is a failure of controlling a RPM reading that’s “good or bad” that goes with a failing CPS but he hasn’t said how it starts up?

What is the routine of the car starting and while during it’s warming up?
More idle information or any characteristics is needed.
During this time the ECU is running programs per the AMM and later the O2 sensor.

If it’s Okay, then I lean towards the throttle body area too.

The engine needs to know when to idle and that’s two different RPMs loaded by AC or not. The AC idle is triggered by the ECU that depends on the throttle switch/air plate position as well as the air through it or around it by the IAC that appears to respond OK.

It has been brought up about other outside air influxes that he is going to be working on.
My key is, he says the ISSUE gets created more sincerely when he activates it?

What state of tune are the spark plugs or the ignition system?
This question in general as far as any misfires?
My next thought is never want to blame any major electronics that we cannot test definitely.

So that leaves the crusty little intermittence group of gremlins to chase out.
As always 🤔

Phil