(First 940 I've worked on.)

Friend bought a 1994 940 Regina that had been sitting ~6 months (owners bought a new car; then decided not to keep the 940). Car had been a daily driver; maintained by a local (not Volvo) shop. Friend test-drove it ~1 week. Check-engine light came on.

Two driving problems: 1) with engine cold, it would start and stall. It took 5-10-15 tries before it would stay running at idle; 2) when driven it skipped and hesitated. In the shop I noticed that the idle would race up to ~1500 just before the electric radiator fan came on.

Checked/found and fixed/replaced, one at a time

a) Throttle plate wasn't closing - cleaned and adjusted it
b) Vacuum hoses, intake manifold gasket, and air-intake hose good
c) Pinching IAC hose didn't stall engine; after (a) above it does
d) ECT readings were poor - replaced it. Check engine light went out.
e) Fuel filter clogged - replaced

Doing a-d above didn't change much. After replacing the fuel filter, the start-restart problem was down to 2-3 tries. But it's now a problem hot and cold. Before - with motor warm - it would start and stay running 1st try.

After a-e above, there was still some roughness in the idle and during acceleration. The distributor cap, rotor and wires were new but I replaced with a used set. The idle skip and hesitation is now gone.

Timing belt is new and timing is correct.

I suspect the IAC might be sticky but I cleaned and it tested good.
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240 drivers / parts cars - JH, Ohio