[Dark Skies]

I'm about a gnat's cock from going insane right now.

As mentioned previously I've been suffering an annoying problem with poor idling (shuddering on the edge of death) on my (early)85 fuel injected 944. It was mainly noticable when I switched the lights on or the radiator fan cut in. The problem has now progressed, although in truth it was never far from this before, to stalling at traffic lights or junctions. She's fine on the fly at motorway speeds.

My first question is this - why is it you always end up getting stuck behind a prat who can't read the road ahead, stops for no good reason at every clear junction, or drives at fifteen mph when you're trying to nurse a spluttering car home?

Secondly - I've checked or replaced the following recently with no change in the symptoms:

Timing and balance belts - Porsche fitted.
Spark plugs
Fuel filter
Air filter
Ignition leads
Coil
Distributor cap
Rotor
exchanged alternator (with regulator)
Battery (last July)
Checked all earth leads
checked all fuses and connections
Checked relays
Fresh fuel
Injectors (I removed them, attached a reservoir full of injector cleaner and operated them off a 1.5 volt battery harness to check they worked (all squirted the same volume of fluid in the same time - figured that they wouldn't all fail at once so although it's hardly a very technical approach it must prove they're at least reasonably in spec).

Bypassed the engine earth strap with a booster cable attached to the inlet manifold straight to the neg terminal of the battery.

Apart from the exchanged alternator (seemed to be low on output) which was borne out of desperation the rest was just done out of regular servicing.

Soooooooo ... anyone got any ideas why my car still won't idle but goes fine on a straight road? Fuel pump is a little old - worth replacing? I'd have thought idling would be good but top end would struggle rather than tother way round.

Starting to get a little desperate here - help would be much appreciated.