No problems, glad to help!
Certainly idling will be affected by not having the switch present, I suppose under different conditions such as cold weather, it could misbehave in different ways - in my case it was last summer when I bought the car, so nice and warm and dry, and I found the car would idle pretty well without it. There is every chance that you may have other issues that need ironing out though.
On the SPi the key area to check for trouble is the vacuum lines. The most important being the one which goes from the manifold to a fuel trap (a small black plastic box mounted to the left of the air box as you look at the front of the car) and then on down to the ECU. From manifold to trap is a small plastic hose with rubber elbows, then a longer one runs down to the ECU, on the underside. This is the MAP sensor (Manifold Absolute Pressure). The MAP sensor is the main factor for the ECU to set the fuelling, as it tells the ECU alot about the level of vacuum in the manifold. This then indicates the amount of engine load, air flow etc. Check these two pipes carefully for any cracks or splits in the pipes or elbows. It is best to remove them to do this (can be done without removing the inlet manifold, just a little fiddly at the back there). I would take them off and cover an end and suck - you should be able to get them to hold vacuum against your finger without leaks. Also check for any cracking in the elbows. You can do a similar suck test on the fuel trap too.
If they are at all suspect, renew them. Then there is also a vacuum line (Should be red) which goes from another port on the back of the inlet manifold down to a valve on the underside of the air box. A leak here will tend to cause a high idle, and will lean out your mixture somewhat. Note that the valve it connects to can also leak, so similar 'sucking' tests are wise here (pipe and valve). All the red line does is act on the valve to operate a hot / cold air flap, which will close as soon as the engine warms up, so is mainly for cold running. If the valve is leaking you can just plug the end of the red pipe temporarily to eliminate the vacuum leak. Again though, make sure the red pipe is intact and not leaking, and that it is connected at the rear of the manifold.
Post back with progress / questions and any picture of anything you need identified or explained and I'm sure it'll get sorted out easily enough.
By the way, there are some great pinned guides about injection cars, including good pictures and information relating to the vacuum lines here :
http://www.theminifo...oint-injection/
Cheers
Edited by carlukemini, 30 April 2015 - 08:18 PM.