Hello All,

Patient is my '90 744GL w/223k. When first started every morning it will rev to 1200 rpm or so and stumble, frequently dies but will usually restart and run OK, however it never idles really cleanly and is quite noisy.

I have replaced the plugs/wires/cap/rotor and cleaned the throttle body but the problem persists.

I leave the serious wrenching on my car to a friend who is a fine mechanic but has little experience of Volvo's, he is convinced the problem is a vacuum leak of some sort but can't find it. The narrow hose from the flame trap housing to the inlet manifold had a crack in it but changing it didn't do anything either.
The other hoses look OK but are there any "usual suspects" I should check more carefully?

The return tube beneath the flame trap looks oily and nasty however I can't see how I can access this without taking most of the car apart... The trap itself is clear and the car has no leaks or oil consumption issues.

As alluded to in the title, the car refused to start after lunch today & would turn over but showed no sign of starting. I came back about 3hrs later and it started OK which only served to annoy me as I have no idea why it chose today.

I would be grateful for any suggestions where to start on this one...

Thanks for listening.

Matthew