Hi peeps! I posted earlier ago on this board about my 1.8 16v KR being flat on power. I closed that thread thinking I solved the problem by getting a new crankshaft gear (the little notch on it was worn out and allowed some play). This did not sort my flat power delivery. I brought my car to the MOT, and discovered there that at idle my CO % (without a cat) was a really low 0.30% So i’m guessing that’s where my problem lies, as the engine drives and performs well otherwise, just really low on power and pretty good on fuel (I can get 700km’s on one 55L tank..) I checked my plugs wich also seems to say that it’s running rather on the lean side. i’ve ruled out other things: Got new oem bosch spec injectors and seals. Fuel quantities between injectors are even. No dribbling of the injectors. timing is on point ISV buzzes and works cold start system does not work. Car starts difficult if cold, but once it’s been started once it fires right up each time, no hunting. new fuel pump, no vacuum leaks. Does anyone know the procedure to adjust the CO%? I know you need a long hex for the fuel distributor and that clockwise is richer and anti clockwise leaner. But i’m not aware of the extra steps, and also if adjusting co will adjust the mixture across the rev range or just only at idle. Any experienced with k-jet that can help me set it up to around 1.5% or 2 % CO? Thanks alot!
Aim for 2.5% and as far as I know it adjust the entire range to a degree. You turn the long 3mm allen key. I did mine with a Gunsen CO meter back in the day but would use a Wideband now (have one in both my cars, invaluable imho). There is a sequence, you need to remove the engine breather from the intake.
yeah 1.8-2 is just a base figure to aim for, you'll probably want extra https://clubgti.com/forums/index.ph...air-and-tune-your-mk2-corrado-1-8-16v.195423/
I guess my loom doesn’t have the spade fitting :-( Do I have to make one myself? Or can I adjust CO without the ISV in set up mode? I’ve taped in all the wiring, so no clue to as what wire colours are from the ISV
if its a factory KR then it should be there. look at the coil negative 2 pin white plug, there should be 2 red/black wires on one side and one of these is the one with the spade connector inline you disconnect
I can’t see them myself, the car is not a factory 16v. It’s been swapped. I believe the loom I used is from a corrado 16v Don’t know how to place images here, so i’ll link to mine: https://ibb.co/X5gB102 https://ibb.co/52tXD3T I don’t see any red wires :-(
on the actual coil itself, round the back was the full corrado engine bay loom used, i.e. all of the wiring for the isv, warm up regulator, 5th injector, over-run cutoff & cold throttle enrichment behind the airbox is all there? if its just had the ecu loom dropped on top of the old golf engine loom, thats why it isnt there and you dont even need this plug since you'll have no isv controller to put into setup mode
I have the little module in the centre console if that’s what you’re referring to. I do have the wiring for the cold start etc, but seems there’s a problem there too as my cold start does not work (injector does spray when I put power on it, just not when it’s on the car so there’s something wrong in the wiring I guess) Not everything behind the airbox is there, I don’t have the overrun cut off valve but the wiring for it is there. So I do suppose I have all that wiring present, I just can’t seem to find any wire with spade Or i’m blind as a bat.
ok if you really cant find it in the bay you could cut the red/black wire to the isv control module and put a spade on that instead it'll do the same thing. but only if the module is actually connected up to the coil signal as if you really cant find it, perhaps its not there but yeah. look at the wiring on the 2 spades on the back side of the coil (behind the plug lead) one of them comes from the ecu, the other one goes to the fusebox and should have a 2nd wire in it with spade for isv control module
As far as I can remember I did it both ways and didn't really see a difference. If you can't put ISV in idle setting mode as long as car is fully warm (80c + coolant temp) it's not the end of the world.
yeah all it does is stop the isv compensating for any idle adjustments really, so long as the base idle screw isnt way out of whack you'll be alright
if you did that it'll possibly cut out or idle way off, the controller still has the isv at a base PWM afaik. give it a go whats the worst that can happen
Heya, sorry to bother again. I unplugged my ISV when the car is at operating temp and it idles fine without it, bit low at that. With ISV it idles at around 1000-980. If I disconnect it it will idle on the low side at around 900-850. Would it be fine to unplug the isv if the car is at operating temp and adjust CO without the isv plugged in at all? And just plugging it back in after the adjustment? So I don’t have to make a seperate spade connection on the ISV wire. Thanks in advance!
Set it unplugged then check mixture again. ISV draws air from after the fuel metering head so technically it shouldn't make any difference.
