Hi all, the never ending story goes on and we've got here the next season called The Annoying Idle. Following on from this thread http://www.clubgti.com/forum/showthread.php?t=188600 From the director of "Hey, it's been so long since the car last broke down"... Co-starring "This car may be reliable today..." I'm glad to present...." THE ****N' IDLE ! ! ! " The story goes as it follows: One good KR engined Corrado has had its idle set by unplugging the red coil wire and oil recirc pipe out of the airbox. In the last days, (and before, but just to clarify that idle was correctly set) it's been idleing at 1000 - 1500. Idle didn't fluctuate from 1000 to 1500, but it was steady maybe at 1000, then after a couple of minutes 1200, then after some time 1500 etc... But today it almost stalled on idle! The action begins... I stopped at a set of lights and idle went down to 400, then quickly up to 1000 and then it fluctuated at 800-1000-800-1000.... I thought it would be a good idea to put my foot on the accelerator pedal (just enough to keep revs at 1000), and it rattled . When I started moving, it also rattled a little bit. It occurred for about 4 or maybe 5 minutes, then it went back to its 1500rpm idle.... I parked it and shut off the engine. Then, with ignition on (but engine OFF), ISV buzzes but if I disconnect its electrical plug and then plug it back in (ignition is still ON), it doesn't buzz until I turn the key to OFF and then turn it back to ignition.... Is that the way it should be?? Just to clarify, -no air leaks -CO is ok -fuel pressures are ok -coolant temp senders may be faulty edit: -isv switch is actuated correctly edit2: -when I unplug the coil red wire, idle isn't affected (should it?) edit3: yet another question. I'd like to replace the idle screw o-ring. is that a matter of unscrewing the screw, replacing oring, screwing it back in? any part number for this oring? I've spraid WD40 on that screw and it made no change on the engine note... edit 4: if I disconnect ISV's electrical plug with the engine ON, revs fall down from 1500 to about 1000. thanks for reading.... edit 5: Went out for a drive and the idle is at 1000 when cold and warm. Once the engine gets hot, it climbs up to 1300. When rad fan kicks in, it goes up to 1500. When all of this happens, while accelerating i.e. up to 4.000RPM, if I press the clutch and release accelerator pedal, revs fall down sloooooooooooooooowwwwwwwwwwwly, taking about 1 second to fall only 100 or 200rpm........ I've set the CO back to 1.000 (and ~1100 with rad fan ON) or so by the idle screw. Once done, I've pinched the ISV pipe and revs haven't dropped at all!!! I even disconnected ISV switch and it made no difference at all (while a couple hours ago it did affect idle)!!! However, the ISV was buzzing (I also checked it with engine off but ign on, just in case engine vibrations made me think that ISV was buzzing.... and yes it was buzzing!!).... I can smell a strong oil smell coming out of the exhaust now.... OMG please I hope the engine dies soon and so it's time for ABF
3 things to start with 1.did you check the valve timing (cam belt timing) after the crash 2.is the throttle valve switch clicking when you open it 3.you said in the other thread (loss of power thread) that revs dropped really slow,check the wires on the throttle valve switch are not broken
1. Not yet. I'll be replacing it soon (I hope), but this IDLE mess didn't happen before yesterday... 2. Yes it is. ISV is buzzing as well, and I think it would't if that switch was knackered. am I right? 3. Yes that has been happening from time to time, randomly, but mostly with hot engine thanks for your help Neil btw I've updated the first post
ok id check that cam timing as soon as you can isv will buzz even if the throttle valve switch is open check wires anyway also a point rubjonny made out to me is on the throttle body where the spindle is there are some nylon washers and these can crud up or wear i think he said and can make for a sticky throttle so worth checking throttle wires throttle mech,see the white nylon washers at the bottom
Hi, I checked isv switch and it does get pressed by throttle body, but thanks anyway, that nylon washers thing is good to know so what difference does the throttle switch do to the ISV then, if you say that it will buzz even with the switch depressed?
that im unsure of,maybe it adjusts internally and closes the valve slightly to let less air through??
know what? The car has been running like a dream this evening... .. . . I just started it and set IDLE at 900pm without disconnecting the red wire and crank ventilation pipe... I had to give the idle screw 2 turns clockwise in order to achieve the 900rpm idle. What's interesting is that 2 or 3 weeks ago I set the IDLE back to 1000rpm by turning something like 2 or 3 turns on the idle screw...... I'll replace the idle screw o-ring tomorrow and I hope (and pray for!) it's the cause... but I sprayed wd40 on the screw and it made no difference at all...
it sounds like problem i had on my digi, the o'ring wasn't leaking but it was worn enough that the screw would unwind itself after a week or so. it is just a case of unwinding the screw till it pulls out, then pop off o'ring and replace
well it's been a while since I started the thread, so apologizes there please! I set the idle at 900rpm and after a couple of days, it climbed back up to 1200; so I gave the idle screw two turns and re-set it back to 900. After a couple more days, it went back up to 1200 so I had to turn it two more laps.... I had a spare throttle body at home so I pulled its idle screw+o-ring out and dropped it into my car. The "old" idle screw was all the way knackered (I wonder how can it have happened??) and was wiggling around... Since I've been using the "newer" idle screw, the idle has been OK for the last 2 weeks and another thing that has cured is that (mostly) when I started moving the car (1st gear) it looked like if I had a totally dead engine mount as the whole car was "jumping" while using the clutch in order to start moving.... Now this isn't happening any more! So it was an air leaking idle screw in fact!! edit: now the revs are not falling down slowly any more, so another fixed thing edit2: the newish idle screw is "harder" to turn than the oldish one Sorry for this huge paragraph LOL and thank you all for your help, once more!!!
