Not 4-pot unique, but on any older miggy, I think this thread is worth a view, especially if you smell petrol in the cabin:
http://www.omegaowners.com/forum/YaBB.pl?num=1186065848On early 4-pots (inc. our N/96) there wasn't a flametrap/breather-filter fitted between crankcase breather pipe and camcover. Well worth the money to get one from Vx if yours doesn't have it. Should reduce clogging of the breathers beyond this point.
With the breather cleaning, I can't over-emphasise the importance of clearing the small breather jet just below the throttle, as detailed well in Grumpy's How-to. Ours didn't idle reliably even with a brand new IACV until this was cleared.
One more: In the wiring tray that runs fore-and-aft along the top of the engine beside the camcover, there is a potential for short-circuits between wires.
This comes about because the injector connectors are integral to the cable tray, with the wiring emerging vertically. Either side of these 8 wires, running horizontally, is a mass/mess of wires going to all sorts of sensors/DIS/EGR etc. Because of the horizontal/vertical crossovers, there is potential for chafing of wires with engine vibration, and shorting out once the PVC insulation has been worn through. This killed the Coolant Temperature Sensor on ours, and its replacement, before I discovered the real problem.