[anilv]

HI Higgy,

I believe rock-steady idle is not the strong point of carburetted Volvos.

Things you might want to check.

1. Plugs. Are they in good condition? is any one different from the others? They need to burn equally so one that is different from the rest will lead to poor idle.

2. Plug wires. These degrade and poor connections may lead to poor idling. Also if one wire is bad it may cause the plug for that cylinder to be different from the rest. Check that the wire from the coil seats fully as well.

3. Dist cap..is it in good condition.. One way to check is to observe the engine in darness (very dark). You may see arcing across the dist cap.

4. Check all the hoses coming to and from the carb.. follow vacuum line to ensure no leaks. I have no problems pulling the vac lines off, putting it in my mouth and seeing if they hold vacuum. I use wet wipes to get most of the crud off.

5. Fuel filter good? Might be worth checking. SHops have pressure testers but I just disconnect the hose to the carb at the fuel pump and fit another hose (leading to a container) and crank the engine.. if a steady spurt comes out then the pump is good. If a weak stream then either the pump is bad, filter is clogged or the tank outlet is clogged. It could even be the metal line from back to front is bent, reducing flow.

6. Strong spark? Check with the engine cold and hot. Sometimes coils go bad and the spark gets weak. One sign of this is the coil gets hot. Its ok if the coil is warm or at least as hot as the surrounding parts but it should not be really hot that you cant touch it for more than a few seconds.

Good luck

Anilv