Hello, Just timed up and tuned my car for idle speed, CO etc. as per the guide on here but I have a long standing issue (5 years!). In short, no matter how I go about setting the idle speed, as soon as I recnnect the blue temp sender the idle speed always returns to about 700rpm and the car idles like Jordan (i.e. a dog), with the engine rocking back and forth and the exhaust sounding spluttery. When driving it is very smooth and pulls fine, no pinking, flat spots etc. but this one issue is bugging me. When setting the idle and CO with the blue sender unplugged I always set the idle to about 875rpm and it is fantastic, really smooth, but as soon as I reconnect the blue sender the idle returns to ~700rpm and I am thereafter unable to influence the idle speed at all using the adjustment screw. FYI the car is a 1989 pb GTi, 2E bottom end, GS2H cam, DIY p&p head, full supersprint exhaust. Engine and ignition timing correct to the best of my knowledge (ignition timing checked a few months ago). Recent lift pump (after fitting this the idle CO shot up to 3.5% haha, now down to about 1.7%). Recent blue sender (made no difference). Any suggestions appreciated...
I suspect that its your cam thats upseting your idle a little. 800rpm is what mine used sit at, with a standard cam. have you tried raising the idle with the temp sender connected by turning the screw on the trottle body? also, did you clear the ecu memory?
Hmm, well, I bought the GS2H as it was advertised by Kent as a "fast-road cam with a smooth idle", and as I say, until I reconnect the blue sender the idle is sweet and non-lumpy at around 850-875rpm. With the temp sender connected I am unable to influence the idle speed at all using the adjustment screw. I always follow the guide in the FAQ when adjusting CO and idle, but the idle speed never remains where I set it.
