Album56

Quote:- just a thought but you remove breather and then bts and then rev 3 times over 3000 and allow to idle, set idle speed and then switch off, reconnect bts and breather and restart. but you never mentioned turning off before reconnecting. Yes you are right, is switching off important? My trouble is that I cant get the idle to 850rpm with the BTS disconnected, as soon as I disconnect the BTS with the engine hot idle rises to 1100rpm & the idle screw makes hardly any difference over the whole of its travel which could mean false air is getting in but I have checked all the vacuum pipes & devices connected to the manifold & all are good. maybe inlet manifold gasket or injector seals but there are no noises whistles/hisses or sucking air noises & it runs fine on the road. Mick

Cheers guys, new dizzy then. Its a real pity the hall sensor cant be changed easily because some Bosch ones are available for around £30-40 as opposed to the cost of a new dizzy which I imagine is gonna be around the £200 mark plus then having to re-time everything. Does anybody know the VW & Bosch part Nos for a G60 dizzy? I was told by the dealers that 4 different ones were fitted to the G60 & mine is a type 4 which presumably means the latest one when I got a new cap & rotor. Mick

Well have a nice shiny new CO pot set at 500ohms, made no difference, car still runs perfectly except for this cursed wandering idle when hot, starting from cold its fine & behaves perfectly even settles down to a nice 850rpm idle for a short time until things start to warm up after 5mins or so from cold & then idle starts to wander up & down between 850 & 1000rpm . Have read that the hall sensor in the dizzy can become temperature sensitive when they get old & tired, this is my next suspect. A hall sensor type dizzy is very basic, just a 3w sensor with a revolving metal disc with 4 windows & a permanent magnet. The only bits that move are the metal disc with windows & the rotor, but the sensor itself does become tired apparently & if it doesnt fail altogther it can cause wandering idle symptoms when hot. Has anybody managed to replace the hall sensor? they look quite simple to replace if it wasnt for the metal disc with windows which is in the way. Any advice would be gratefully recieved. Mick

Do they have the same part no? if not then there are likely to be differences.

Would fitting 16" wheels on a stock G60 be an easy way of getting longer gears & how much difference does it make in practise? I have always thought 1st/2nd gears are a bit short on my G60 & I dont want to go to the bother of box out etc. Also it might make the speedo which reads 3-4mph fast more accurate. Anybody have experience of this please. Mick

Next stage new air temp sender/co pot part no 037 906 040B £79, arriving tomorrow at dealers, I'll initially set it to 500ohms across pins 1 & 3. Original one has gone faulty after I wound it up & down, it now goes dis at the higher resistance setting so its set on 180 ohms at moment. Could have been the co pot all along causing the idle to wander I guess, naa that'd be too much to hope for. If the new CO pot doesnt fix it then the ECU is coming out again, I may try swoping chips with the one from the spare ECU.

Apparently the heater supply for the lambda on a G60 doesnt come on until the engine is running so that turned out to be another non-fault. This fast idle when hot is an electrical/electronic problem I'm sure because it varies up & down in small steps sometimes like something is breaking down or a bad connection. I have checked all the loom connections which are all good, throttle switches are good, earths are good, the distributor still has the plastic cover over the fixing bolt so the timing is still as set at factory. The main suspects left are the dizzy, apparently the ECU uses small variations in timing along with mixture variation by the idle valve to achieve a steady 850rpm. The ISV is clean & working. What I am not sure about is how the timing is varied, is it a mechanical function within the dizzy, ie. the hall sensor moving or is it electronic within the ECU? I still think its tied up with the fast idle on start-up function, is this part of the Eprom function. These are quite technical questions I know but I have a basic knowledge of electronics & I'm determined to find the problem. Cheers Mick

Hi G60_Marc, thanks for the info, that explains a lot so the black wire in the 2w cable acts as a screen to stop any interference with the 0-1v lambda signal & it is earthed thro the engine mount, thats why its critical to the correct working of the engine management without that good earth the signal wire wouldnt be screened properly & induced voltages could upset things. Not happy to hear that +12v heater supply only appears when engine is running, will have a look at it again next week. Basically I've been chasing faults that were'nt there. Thanks again for the info Mick

Was wondering how I could easily check the oxygen sensor (lambda) was working now I've run a new heater +50v as getting at the wiring with the engine running to check for 0.2 to 0.8v on signal wire isnt easy. Anyway went to fill up with V power 14mile round trip & noticed that its running hotter (leaner mixture?), had been running coolish recently presumably due to over rich mixture because lambda wasnt working. Its quite cool out tonight 10c too so methinks the lambda is having an effect & leaning the mixture as it should do, I have filled the tank & will see how many miles it'll do, used to get around 380miles on a tank of mixed driving .

Quote from JMC:- Not sure why you haven't had an answer to this but to be honest I'm struggling to follow what you are doing (maybe that's the reason). Some pics might help. With regards to earthing, on my lambda sensor connector the earth is directly to some adjacent metal work, it doesn't go anywhere else. Thanks for your reply, yes its difficult to follow but all I was trying to do was test the lambda loom (car side), when I found there was no heater supply I assumed wires were broken where the loom is clipped to the bulkhead & bends 90 degrees out to the engine mount but it turns out that part of the loom was fine, the heater supply is missing on a red/white wire connector at the back of fuseboard so looks like thats come adrift behind there somewhere, anyway I have found ignition switched +50v that I can use. Pin 3 on the lambda plug has the black wire that runs with the purple wire in the screened 2w cable all the way back to the ECU where the purple wire terminates pin2 & black wire is cut back it seems at manufacture & doesnt connect to anything. This is the wire that earths on the engine mount at lambda end & we are told is critical to the correct working of engine management? So it connects a good earth at the engine mount to nothing. Mick

Well would you believe it, when I pulled the rubber boot back on the ECU plug the cable from the lambda was easy to recognise with its purple & black wires & the black wire was cut close to the sheath, looks deliberate at manufacture so the earth that we are told is critical for engine management doesnt actually connect to anything. The purple signal wire connects to pin2 as it should. Seems very odd that VW would go to the trouble of a 4w lambda & terminate the earth at the engine mount end, unless the capacitive effect of the wires is helpful, also I thought I could see the edge of a foil screen where the outer insulation was cut. The signal wire does carry very small voltage variations, apparently the ECU applies a standing 0.45v & when the probe gets up to temp the signal should vary from 0.2v to 0.8v if its working ok. Still a bit woried about the +50v heater supply, I read somewhere its not fused & the fact that its missing from the red/white wire at the fuse board end suggests its come adrift somewhere there but its impossible to see much behind there. Anyway one mystery solved .. Mick

Registered with CC of Canada to ask question on there, its an active forum & Dennis their technical guy is very knowlegeable, also gonna try looking under the rubber boot on the ECU plug to see if I can recognise the 2w cable with purple & black wires at that end. When you look closely at the loom at the lambda end there are 4 wires, the heater wires are lose inside the sleeving & the other 2 wires, the lambda signal & earth from the mount are in a separate 2w cable inside the sleeving. This makes sense the heater batt/eth comes from fuse board & the other cable goes across to the ECU. I'll update this thread when I get a definitive answer. In my search for an answer it seems that problems with the G60 lambda loom are common as cars get older & symptoms can vary car to car from quite subtle, slightly high idle & rich mixture to almost undriveable. Mick

Bump The earth that is derived from the engine mount into the lamda wiring loom on pin 3 goes where? Should it go to the ECU plug, possibly on pin 6. My lamda loom is bad, testing from the lamda plug back into loom there is no heater battery on pin1 with ignition on, pin2 heater earth is ok, pin3 doesnt seem to go to ECU when tested, pin4 the lamda signal goes to pin2 of the ECU plug ok. Really need confirmation that the earth from the engine mount into the lambda loom goes back to the ECU so I can rewire it, doesnt seem to go anywhere at the moment but it is "critical to engine management system" , have found a way to easily get +12v ign/on battery to pin1 heater supply so just need this info please anyone. Mick

Payment made via Paypal :D :D :D Cheers Alex

Well I dont understand it but the lamda heater battery loom is ok thro to fuse 18 & the fuel pump works ok & yet there is no battery on the red/white wire behind the fuse panel with the ignition on?? Have decided to run ign on battery wire from coil to lamda plug pin1 as its the easiest way . Still not sure where pin3 (engine mount earth) goes. Anybody any idea.

Found this in an old thread by Supercharged in 2008:- Plug connects to engine loom at bracket ontop of rear engine mount and on the G60 / 9A probe this bracket also provides an earth which is critical to the engine management, The VR6 part earths thru the loom back to the ECU (I assume) - deffo worth checking all engine mounts are in good condition when fitting a new part as VW give little slack on the cables to allow for movement (altho it's usually the ECU loom side that breaks and you need to either use repair wires or get a new plug from VW - £7ish) So can I take it that the earth from the bracket should be back thro the loom to the ECU, if so thats busted on mine as well as no 12v heater supply, other wires in the loom, signal & earth from batt -ve at lamda loom plug seem ok. I guess the break is gonna be where the loom bends out from the bulkhead & continual movement of the engine flexes the wires at that point, I'll strip back some of the outer cover & have a look.

The earth that is derived from the engine mount into the lamda wiring loom on pin 3 goes where? Should it go to the ECU plug, possibly on pin 6. My lamda loom is bad, testing from the lamda plug back into loom there is no heater battery on pin1 with ignition on, pin2 heater earth is ok, pin3 doesnt seem to go to ECU when tested, pin4 the lamda signal goes to pin2 of the ECU plug ok. I guess that is why my idle has been a bit flakey of late & its running a bit rich, help would be much appreciated. Mick

The red/white apparently comes from the fuse panel & uses same fuse as the fuel pump which is working ok so not the fuse blown. Its stand on yer head time with the door sill cutting into your back peering up at a mass of wires/plugs behind the panel to see if I can see that red/white wire to check for 12v that end. The loom in the engine bay disapears down by the fuel pipes & servo vacuum pipe but there is a bit of slack after I unclipped it from the bulkhead, cant see where it goes but can get my hand down there & feel it going into the corner & it seems quite loose at least thro the 1st skin, can also hear what sounds like a connector moving about inside. Need assistance now, someone to tug gently on the loom while I look up at the wires behind the fuse panel. If I cant find it then I'll just have to find a suitable ignition switched 12v to use & run a new wire. One things for sure it wont have done my fairly new lamda probe much good & what about the old catlytic converter...

Closing in on a problem now, there is no 12v heater supply to the lamda with the ignition on, looks like that old favourite the lamda loom to the plug by the engine mount again. Has been repaired years ago by the dealers when it failed MOT on emissions then the signal wire & the earth next to it were pieced out & repaired. Cant see any obvious breaks but the 12v on pin1 is missing & pin3 has no earth. If I am correct pin1 red/white is +12v, pins 2 & 3 should be earths & pin4 the signal wire to ECU.

Well tried the other ECU today & if anything it made matters worse, was idling at around 1200rpm when warm after set-up, tried switch off engine & disconnect ISV plug & then re-start & that improved things to around 1000rpm hot idle. Put the original ECU back & back to square one. Now thinking I need to get timing checked & make sure the dizzy etc is working correctly, strange that this started to happen shortly after I had new plugs/dizzy cap & rotor. I was told at the time that several different Bosch distributors were fitted to the G60 & mine is a "type 4". Does anybody know if new ones are still available from the dealers or Bosch & roughly how much it is? Found a thread on the Canadian corrado club forum from a guy who had a similar problem, read thro it quickly & he changed alot of stuff & checked everything but there didnt seem to be one thing that he did that definitely cleared the problem it just went away as mysteriously as it appeared on his car?? I'll read it again more carefully in a minute to see if there are clues. Mick

Tried setting the base idle again today, got her nice & hot pulled the cam cover breather pipe off & pulled the plug off the blue temp sensor, the idle increases to approx 1100rpm, the strange thing is the idle screw has no effect on idle speed that I can detect whatsoever until it comes out & then air whistles in & idle increases to 1250rpm, over the whole range of its travel it doesnt change the idle from 1100rpm so I just unscrewed it a turn or so from fully in & left it there. Checked the CO pot which was set at 403 ohms before I tried adjusting it & found that did affect idle speed when adjusted by many turns but not by much. Ended up setting it back to 403 ohms & when the plug was put back on the blue temp sensor the idle falls back to approx 900rpm but as soon as I blip the throttle to 3000rpm 3 times .to clear the memory it idles back at 1000rpm each time. The throttle cable is fine & not sticking. The strange thing is when started from cold it behaves perfectly for the warm up cycle & after idling at 1000rpm for a short while then falls back to 850rpm until temperatures start to rise & then it will start to rise again to 1000rpm. I am determined to track this down, took the plugs out the other day after a good run & they looked slightly rich to me, black but not sooty but not nice brown colour either. Trying the other ECU tomorrow, will update this thread.

Hi guys , my G60 has a wandering hot idle any where between 850-1000rpm after 18yrs of rock steady 850rpm, have checked all the usual suspects, all vacuum pipes are fine, blue temp sensor changed, ISV is clean & working ok, CO pot appears ok, idle screw & seal is new, idle microswitch operates & tests ok, loom tested for continuity from engine sensors/switches to ECU plug ok, all earths cleaned/tightened. ECU removed & inspected, nothing obviously wrong, multi-pin plug looks clean, sprayed with contact cleaner anyway, lamda probe recently renewed with geniune Bosch one, lamda earth wire good & tight. The car is completely stock & now I'm wondering if the fast idle on startup function is intermittently cutting in because it wanders to 1000rpm but no higher? If I slow the idle down to 850rpm by letting the clutch start to bite in gear it will quite often then stay at 850rpm until I blip the throttle again. The 2 suspects I have left are ECU or dizzy faulty, I take it the fast idle on startup is a function of the ECU, Ive got my hands on a good second hand one now & will be fitting that next week to see what happens.... Corrados heh, never a dull moment :D

Any good quality 10-40w semi-sythetic will keep your PG G60 running well, I use Castrol or Mobil depending on whats better value at the time. Mick

Yes my windows do rattle well when down, 4 for me please. :D

I dont have your engine but on my G60 there is the knock sensor plug that looks like that that plugs into a fixed socket into the loom down near the starter moter in that area.