Rough Idle When Cold. 1994 Volvo 940

volvo
940

#1

1994 Volvo 940, 275k miles, Regina Rex ignition, Non-turbo (Vin 88 B230F).



Car has difficulty starting, with rough idle when and stalling when cold. Smell of gas seems to accompany the starting. Rough idle around 500 rpm for 30 to 90 seconds, then idle momentarily spikes to 750-1000 rpm before settling down and then running fine. Generally this does not happen when starting the car warm.



Have replaced fuel filter, air filter, cap, rotor, plugs, wires, IAT sensor, fuel pressure regulator, cleaned throttle body, replaced injector o-rings, intake manifold gasket, exhaust manifold gasket and cleaned the fuel injectors. Idle control valve cleaned and not setting off a code. All grounds checked, cleaned and set with dielectric grease, vacuum elbows replaced.



On board diagnostics report 1-1-1 (no problem). Plugs are tan. Compression runs about 150 PSI per cylinder, holding steady for 20 minutes. vacuum gauge shows rapid fluctuation between 19-20 in hg.



Ideas?