aye,real fun job aint it. ya reckon its worth a shot? edit:thing is,the problem clears and then revs freely? i dunno,im racking my feckin brains...its as though the ecu is altering/correcting something? neil. Edited by: riley
well..it is something g60's suffer with, and if youve got one its not gona cost nothing does it smell rich/sooty tailpipe etc?? and black smoke when it bogs?
well ive just(earlier) noticed that it smokes from the exhaust when the problems happening it dosnt use a drop of oil though? weird anyway,i went for some optimax earlier,and i managed to get a full vid of the problem starting and finishing/clearing! please only watch this if you think you can help,as its only there for so many downloads/7 days. hopefully you can see where the problem starts through the exhaust and clears up under the bonnet. vid here,quite big i think? neil.
[:^(] problem starts at 12 secs,and clears at 1min 2ish secs. ps:ignore the battery light,it does this weather thats on or not,and the batt light problem only started last week i think. feckinell,sounds a right pile a crap dunnit Edited by: riley
Watched the vid and can see why it drives you mad!!!! I would have thought that for a stable and controlable idle you need to feed metered air via the ISV but you seem to have fitted a K&N to the ISV and it leaves me not knowing of any real advantage to this? Does the G60 use a MAP sensor or a flap type AFM? In either case the ECU will not know where the air is coming from at any time the ISV is active - again conjecture. Have you done a compression test since replacing the head? The smoke didn't look serious to me and once the running problem is cleared it won't be an issue I am sure. As in a previous post, the only reasons for backfires into the inlet are incorrect valve timing (you have checked this many times), incorrect ignition timing (would need to be a mile out but just adjusted anyway), badly sealing inlet valve/s (just reground?), a sticking valve or fault follower. I think that is a complete list but will stand correction/addition. An ECU is a computer and as such will always do the same thing in a given set of circumstances. The problem you show in the video changes for no apparent reason which stears me away from electronics - excepting intermittent cables to sensors. When the fault cleared the engine sounded sweet to me - a credit to the hard work you have put in. If you need a compression tester let me know and I will run it round. Please remember that the above are only ideas of mine and in no way am I trying to make light of your efforts. It must be very difficult to keep having to deal with! Cheers Steve.
Looked like unburnt fuel to me rather than oil or too rich. It was onlty there when the engine was back fireing! That is why I think it will go away with the fault - if the bores are not damaged through lack of lubrication!!!
i spose the question is..is the problem being caused by too much fuel or is the excess fuel due to another prob
Excess fuelling would not cause backfires into the inlet system? Although a cat bypass is fitted the ECU still reads the lambda so mixture shouldn't be a problem? NO boost return pipe and an ISV breathing fresh air leaves the ECU not knowing where all the air is coming from though? Remember - I know little about engine management and G60's but pointing out things that occur to me may be problems! Still sounds like a sticking valve or follower to me.
Is that whooshing sound under the bonnet the filter on the isv or is it something else? I would try and recreate the the video again, having the car at the same temp etc, then start her up then time if it's still starting to pop and bang after 12s and stopping it at stopping after 1m 2s, this would indicate to me some programed error, ie a corrupt chip or the ECU signaling through a dodgy wire/connector. if it starts the problem and then stops it after the same amount of time every time, it's something that's meant to happen but isn't or is going wrong when it is.
Euro car parts sell a lambda probe tester for about a tenner, might be worth testing yours. Do you have an a/f guage connected?
Neil,is there a chance one of the bores that the followers sit in could be scored and causing one to stick? Watched the vid,sounds like f**king Darth Vader is under your bonnet Edited by: GVK
yeah the k+n is part of the boost return delete,normally it would take air from excess boost from the throttle body/vent it back in.plenty people running this with no probs g60 uses a map sensor(or so i think ive learnt?) which takes a vac from the back of the throttle body,the 1 meter pipe which is new and in the correct place/correct length. im glad you can tell the smoke dosnt look serious,once the problem stops then it dosnt smoke at all,when giving it some stick or anything,and the oil level has never dropped thanks steve,gav off the rado forum drove it the other week and said it sounded well. pbladder,i think you should sit in all day and download the vid please! [:^(] the whooshing sound is the isv,it sucks loads of air when the problems there,not a bad idea about checking the times etc,but before that vid it did it a couple of times but actually stalled im just thinking... am i right in saying that untill upto running temp the lambda isnt used? if so,whats controlling the fuelling until then? so just to get this right,it seems it could be overfuelling or a sticking valve/follower? cheers gary,just caught your reply before i replied! somethings just clicked now you put it like that gary im guessing you mean a tight tappet? well when i put the tappets back in/re fitted the cam etc,there were a couple that were tighter to get in/out,once in they span freely. ive seen a m8 struggle with plenty and he's always said you get tight ones? thanks a lot guys. edit:gary,isv just bleeds excess boost after so many psi,other than that its sucking in to keep idle. Edited by: riley
One thing you can try, when it's next backfiring up the inlet - pull each plug lead off in turn ( don't give your self a shock tho) see if the problem is isolated to just one cylinder. If it is, the engine might stop when you pull the lead from that cylinder.. Edited by: GVK
Engines run in what we call open loop using values for fuelling on a 'warm up' map - Once at a certain temp or time from start up they will run in closed loop which basically means the fuelling is controlled by Lambda. This is when the voltage from the Lambda is switched not static. Edited by: GVK
cheers gary,ill try the plug lead thing,if i find the dodgy cylinder then the rpm wont change will it what ya reckon to my tappet description?
If it spins freely when in the bore it should be ok - I would say if it was a sticking tappet it might not be so intermittent, but you never know. Only other thing would be an air leak from inlet manifold gasket, also tho - that would'nt be so intermittent either, just thinking aloud really.
aye,ive done way too much of that lately for some reason i wanna go upto the unit in the car and take the cam out
