Hello,

Try to check the timing. Perform an inspection of the timing marks by removing the timing belt cover and see whether the timing marks align correctly at all points.

Next try to clean the insides of the vacuum nipples where all small vacuum hoses are attached to. They may be full of crud after all these years resisting vacuum flow (especially to FPR). A simple tool such as needle or wire would do.

Next inspect rubber fuel hoses all the way from the tank to engine for leaks. High pressure fuel hose from fuel pump to engine suppose to last about 10 years. Replace if its due.

Lastly inspect the valve clearance. In a high milage engine the clearances may not up to specs. Shims may be needed for adjustment. The clearance may be checked on cold engine. Camshaft wear is seldom heard of in Volvo engine but inspect it just in case.

Hope this helps.

Amarin.