This isn't your usual cold start/ isv / hot running problems associated mostly with 16v idle queries. All the above is appears to be working fine on my car. Basic quick history, its a 2l 9a with kr cams, running k-jet on a pre90 loom and ecu in a mk1. The car starts cold on the button, first turn of the key, idles at 2k for a brief moment then gradually comes to a touch over 1k within 5-10secs. When the engine is warm, again starts fine and idles again touch over 1k, no hunting issues hot or cold. Just wondering what is the best way to set the idle? As i think it is a bit high, the idle screw doesnt appear to do much at all. Is there a specific way to set the idle?
Apart from checking for vacum leaks, throtle stop screw adjustment and Co adjustment there is not much more you can do i guess proper procedure with waiting for fan to kick in, disconecting a wire from coil loom or something like that, can be found here, or in haynes manual
no air leaks just found this from DarrynK Try cleaning out the inlet tracts of oil and the airflow flap. If the engine isn't hunting when cold or hot, the CO is correct. 16Vs run best at 2.0 % CO. To achieve 2.0%, disconnect the famous "red lead" behind the coil (after the engine is at temp), pull off the breather hose and block the airbox hole. Start the engine and the revs should plummet, if they don't, the idle valve is shagged and you're idling off the bypass screw alone. Now, with the engine running, turn the idle screw up until you get 950rpm +-50. If the idle wanders or is lumy (engine visibly rocking), insert your 3mm allen key into the CO screw and turn it anti clock to weaken. Just prior to the engine cutting out, turn the key clockwise in 1/8th turn increments until the idle smooths out. Eventually, the engine should settle to a nice, steady idle. This will be 2.0% or very close to. Switch off and reconnect everything. Take it out for a run and when you dip the clutch, the tacho needle should gently fall to 1000rpm, not plummet. If after all that it's still missing and rough, investigate air leaks.
First thing is make sure the timing is right, then mixture, and finally idle speed. The above set up works well, I think I posted that back when I had hair !
