i have a mk2 16v gti 1990 1.8 kr engine , my problem is when i go to start it from cold once i turn the key without hitting the accelerrator it starts no problem but when i hit the accelerator it cuts out it keeps doing that until its warm , ive being checking around with things , ive changed the overrun cut off valve but i have noticed if i unplug at the side of the head there is a switch called thermotime switch when i unplug it from cold its starts fine and runs fine until it warms up . ive changed this switch twice and didnt make any differance . could it be a faulty switch ?
This thermo time switch controls the cold start injector (the one in manifold on its own with blue plug). It sounds like yours is over fuelling on cold start, that's a fairly common problem on these unless fully setup (wur fuel pressures + heater element bang on). Try disconnecting the plug on the cold start, you should get the same. I have to have my csi unplugged through the warmer summer months to aid starting, and re-connect it as soon as it gets a bit colder. Do you have access to kjet fuel pressure guages or a r/r where they can setup kjet? To test the thermotime switch pull the 5th injector out of fanimold, and from stone cold the inj should spray for a second or 2/few. If the injector doesn't stop then the time side of the switch is duff, and if it sprays at all temps (ie when hot) then the thermo side of it is duff. It might be that the injector is stuck open maybe?
