chrisavila100 Posted January 15, 2008 Share Posted January 15, 2008 Hi everyone, right hopefuly someone can point me in the right direction with this one.. i would like to try and solve this myself, but if not it will have to go back to cw to sort things for me..(just a pain in the ass as so far away) Right apart from what im going to describe the car runs perfectly. OK when i put my foot flat down from anywhere below 3.5k the car pulls right to the red line in any gear, both turbos work fine, the transition between the two turbos is NORMAL, there is no problem at all.... But then when i change gear at the redline and plant my foot back to the floor, i get a smallish misfire/slight holding back and a small amount of blackish smoke out the exhaust.. This happens for about .4 of a second then the car will pull through to the red line no probs, then when i change gear again the same thing happens.. If i increase the revs whilst driving, to around 4.5k (off turbo) (and in any gear )then floor it, the same problem happens.. Normal driving of the car is fine, this problem happens weather the engine is hot or cold, it only happens when i boot the car to the red line then change gear and floor it again.. or i bring the revs up OFF turbo to around 4.5k then floor it from there.. The boost gauge seems to stutter around .5 bar when this happens, but then .4 of a second later the boost comes on as it should. The EGT gauge shows no signs of anything abnormal. This problem happens regardless of the amount of boost i run, ie stock levels it happens, and at 1.2bar it still happens.. Now im thinking it must be one of the sensors that control the 2nd turbo coming online, but then why does the car drive fine if i boot it from low revs, ie spooling the 1st turbo first.. The only thing that has not been checked with the "normal misfire check list" is the coil packs, but i cant see this being the problem as surley a weak coil pac would show its self when i floor it from low down in the revs through to the red line? Ive checked all hoses/pipes for air leaks/splits but found nothing.. Well sorry for the long story but wanted to give as much info as poss for you tech guys.. Now im no tech guy, but after lots of reading my guess would be one of the sensors on the sequentional system is not working properly. but which one is the question? Thanks for any help guys.. And if i cant fix it, well its off to Cw's to get it sorted, i hope!! Cheers chris.. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 15, 2008 Author Share Posted January 15, 2008 P.s im off work for a few weeks, so if there is anyone in the essex area that fancys a look/testdrive and think that they could be of any help, then im really good at making coffee, and a bacon sandwich.. If you have the bacon that is:rolleyes: Cheers again.. Quote Link to comment Share on other sites More sharing options...
DamanC Posted January 15, 2008 Share Posted January 15, 2008 I can look but i need to be told what to look for if thats any help? Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 15, 2008 Author Share Posted January 15, 2008 Lol cheers mate.. Well im hoping one of the tech guys will say, "that there is only this or that sensor that would cause this type of problem" Then i can get the bits from Mr T and im sure between the two of us we could fit them;) Thanks again everyone.. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 15, 2008 Share Posted January 15, 2008 To me it sounds like the turbos are working as they should especially if you get 0.7-8 on the first turbo and 1.2 with both? When you floor it are you doing just that? rather than a fast ish increase in throttle opening, only other thing i can think of apart from plugs, is that for some reason maybe due to bad adjustment, the ECU with richen up the mix under fast throttle opening, and it is for some reason too rich, what plugs are you using and what are the gaps? Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 15, 2008 Author Share Posted January 15, 2008 To me it sounds like the turbos are working as they should especially if you get 0.7-8 on the first turbo and 1.2 with both? Correct! no boost problems at all.. When you floor it are you doing just that? rather than a fast ish increase in throttle opening, To be honest i proberly do as most, which is push the pedal to the floor once ive changed gear,(i dont stamp on it) But i have tried progressively applying the pedal but it seems to hold the misfire a little longer:search: only other thing i can think of apart from plugs, is that for some reason maybe due to bad adjustment, the ECU with richen up the mix under fast throttle opening, and it is for some reason too rich, what plugs are you using and what are the gaps? Plugs were replaced by Cw in september whilst going full bpu! After reading up on the sequential system do you not think it could be one of the, EGBV/EGCV/IACV, vsv sensors? Thanks again guys, and for any more help you can give me.. Cheers chris.. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 16, 2008 Author Share Posted January 16, 2008 Right guys, i managed to take the car out for a drive on nice dry roads today and this is whats happening. AS BEFORE:On full throttle from 2/3k (in any gear)its running as it should but once i change gear around 6500k and put my foot back down, i get a small miss then it goes, until i change gear again. OK now, on 3/4 throttle from 2/3k the first turbo boosts fine, but then as the 2nd comes online i get the same misfire/holding back of power, but ALOT worse.... and for a longer period of time....infact it kept missing until i pushed the pedal that last 1/4 to the floor, then the miss went and again it revs fine..... I tried this 3 times, and twice as above happened, but on the other the car was perfect the boost changeover was as smooth as it gets and the power surge from the 2nd turbo was very surprising for 3/4's throttle... Well im now really confused, why at 3/4's throttle its at its worst:search: could it be coil pac related? maybe fuel pump? maybe one of the vsv's..hmmm Well let us know what you think guys....but i think i might have to bite the bullet and pack her off to chris for him to give her a good seeing too:eyebrows: Cheers again guys.. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 16, 2008 Share Posted January 16, 2008 What grade and type of plugs? and try gapping then to 0.7mm. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 16, 2008 Author Share Posted January 16, 2008 Hi mate, they are NGK's fitted by chris w, not sure what grade and gap that has been used.. But im sure they must be the same ones that he always puts in for bpu cars, and gapped to the norm..i presume... Do you think a faulty coilpac would cause this type of problem? But the thing that still puzzles me is, why is the car fine when you floor it from low revs to the red line? You would have thought the problem would show up the most under this sort of stress, and not more so when driven at 1/2 to 3/4 throttle....very weird.. And remembering at full throttle there is no probs between the two turbos but at 3/4 throttle it really misses at the transition point... Thanks again.. Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted January 17, 2008 Share Posted January 17, 2008 Doesnt sound like a spark issue to me personally, possible overfuel at transition as Dick said but your running stock ECU arnt you? Just looking at your spec i assume you have the boost controller connected? If you have the gain set too high this can cause hesitation. Can you clarify that its a missfire and not the second turbo failing to come online all the time, or until you plant it? Does boost rise as it should at transient point? Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 17, 2008 Author Share Posted January 17, 2008 Hi mate, Doesnt sound like a spark issue to me personally, possible overfuel at transition as Dick said but your running stock ECU arnt you? Yes i am.. Just looking at your spec i assume you have the boost controller connected? If you have the gain set too high this can cause hesitation. Yes its connected when i set it up i read the instructions many times,and set it up manualy, ie no auto learn! I set stock boost .8bar then you set the desired boost level ie 1.1bar then adjusted the gain until it hit that amount under full throttle in 4th.. i think the gain is set around 75 out of a possible 100.. Can you clarify that its a missfire and not the second turbo failing to come online all the time, or until you plant it? Does boost rise as it should at transient point? Yes its deffenitly a misfire with some black smoke out of the exhaust, And at transition point when on 3/4 throttle the boost drops off a little as normal then just as No2 starts to come on line it misses and the boost drops and jumps around between .4/ .5bar and will do that until i let off or floor it... And remember WOT from 2/3k there is no problem with the power or transition, in fact not once in 5 years of having her has the 2nd turbo failed to come online... Thanks again for the questions and answers.. Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted January 17, 2008 Share Posted January 17, 2008 There are two easy things you can do to that will cut the check list down: 1) Turn the boost controller off, does it still do it then? 2) If so, then leave it off and try TTC mode as this will bypass most of the electronics involved with the sequential system. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 17, 2008 Share Posted January 17, 2008 Sean could be right about to much BC gain, but the reason i said about the plugs, is because you are getting misfire at WOT and high RPM therefore high load+full boost= injectors at or near max, which usually equates to very rich, and the classic symptoms of plugs not handling either high boost or too rich is a misfire, hence the check plug heat range (could even be too cold,) and check plug gap, as some need smaller gap to cope with high boost. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 17, 2008 Author Share Posted January 17, 2008 Morning guys, There are two easy things you can do to that will cut the check list down: 1) Turn the boost controller off, does it still do it then? Yes Bc off and i still get the same problem. 2) If so, then leave it off and try TTC mode as this will bypass most of the electronics involved with the sequential system. Will give this a try.. whats the easiest way to do this? Sean could be right about to much BC gain, but the reason i said about the plugs, is because you are getting misfire at WOT and high RPM therefore high load+full boost= injectors at or near max, which usually equates to very rich, and the classic symptoms of plugs not handling either high boost or too rich is a misfire, hence the check plug heat range (could even be too cold,) and check plug gap, as some need smaller gap to cope with high boost. I see what you are saying, but remember if WOT from low revs its fine to the redline, no miss and boosts fine! Its only when you change gear and push that pedal back to the floor that you get a slight miss... And after yesterday ive found out that the problem REALLY shows itself when you try and accerelate on 3/4 throttle through the transition point of the turbos... Cheers again guys.. think i will try the ttc mode first... Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted January 17, 2008 Share Posted January 17, 2008 I ruled out the ignition side of things because it runs ok at WOT and full boost, or atleast thats how i have read it. If it was ignition breakdown (plugs,coilpacks,etc) related then this would almost certainly get worse as load increased. Try the TTC mode mate. Easiest way to do it is to bypass the IACV & EGCV vsv's...see the following link, shoulder only take a min or 2 if that! Dont worry about using a check valve as your only trying it out http://www.mkiv.com/techarticles/ttc/ttc.htm Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 17, 2008 Author Share Posted January 17, 2008 I ruled out the ignition side of things because it runs ok at WOT and full boost, or atleast thats how i have read it. If it was ignition breakdown (plugs,coilpacks,etc) related then this would almost certainly get worse as load increased. Try the TTC mode mate. Easiest way to do it is to bypass the IACV & EGCV vsv's...see the following link, shoulder only take a min or 2 if that! Dont worry about using a check valve as your only trying it out http://www.mkiv.com/techarticles/ttc/ttc.htm Cheers mate, yes your correct in saying "it runs ok at WOT and full boost" Thanks for the link, i will try it in the morning, as its pouring down at the mo! But to be honest with the symptons i was thinking it must be vsv related..or somthing to do with the sequential system.. lets hope the ttc mode will shed some light on the problem.. Cheers again..... Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 17, 2008 Author Share Posted January 17, 2008 OK just tried the ttc mode, i also reset the ecu at the same time and took her for a spin... Im afraid guys that the problem is still there in ttc mode! The car now accelerate and boosts fine under 3/4 throttle, from low revs(result) and flooring it from 2/3k is fine too...(as before) But its still the same when i change gear at the red line and re apply the throttle, i still get the same misfire. If i floor it after changing gear at high rpm, i just get a very slight miss just as the boost starts to wind up(.1/.2bar) and then its fine... But if i floor it to high rpm, then change gear and apply the throttle proggresivly then the miss is a lot more apparent.... I also found that if i hold the revs around 4.5/5k then apply the throttle lightly or even fully it misses very badly!! but the less pedal i give it the more misfire i get?? This was all tested in ttc mode! Not to sure what this test was surpposed to tell us, but it has in no way, solved or hidden the problem:( So what do you think guys? could it be coilpac related?? Car has now done 80k on the stock ones... Thanks again...... Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 22, 2008 Author Share Posted January 22, 2008 Hi guys, ok today i replaced all the coilpacs with known good ones and i still have the same problem!! I checked the plugs, they are NGK PFR7AB, The gap is 0.7mm But as i said before these have only done 6k since fitting.. Anybody got anyother suggestions before i send the car chris?? Thanks again... Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 22, 2008 Share Posted January 22, 2008 Well i usually change my plugs before 6K, have you had any rich running problems recently? as this will often cause a misfire due to plugs being sooted up, if i where you i would buy a set of NGK copper plugs and bung them in gap then at 0.8 and see what happens, dead cheap a sets about a tenner. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 22, 2008 Author Share Posted January 22, 2008 Hi tricky, i have a spare new set of NGK BCPR7ES kicking around so will try them in there tomorrow... (i thought the platinum ngk's were good for around 20k?) Ive not had any overfueling problems that i know of, but when i get the misfire it does throw lots of black'ish smoke out the exhaust. Just to note, it does not smoke in anyway, shape or form, the rest of the time. After really trying to note exactly when it happens, the only times it happens is when.. 1) Floor it till red line, change gear,put foot down, miss happens for approx .4secs @.2bar then revs and boost's fine. 2) Floor it till red line, change gear,put foot down, but only 3/4's throttle, miss happens for approx .8sec @.2bar then revs and boost's fine. 3) Drop it down a gear so revs sit between 4.5/5k, then give it any amount of throttle and it will miss, for approx .8sec, but the more throttle you initially give it, (after changing down) the less it will miss, then it revs and boost's fine to the redline again. I took a pic of two of the plugs i pulled out to check. They looked a bit white'ish in the flesh but not as much as the pictures show.. Cheers for the help again mate... Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 22, 2008 Share Posted January 22, 2008 Plug colour is OK but TBH you can never be 100% certain going by colour alone, its the area down in where the ceramic insulator meets the body that you cant see that gets sooted up and causes problems, i know it doesn't really sound logical but i have proved this countless times when tuning bikes, and unless you have a proper plug cleaner, its best to just change them,last time i had a mixture problem that caused a misfire on boost from too rich mix, after that i just kept getting a miss, as soon as i changed them it was fine. Did you pull all the plugs? and did you check the insulators? Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 22, 2008 Author Share Posted January 22, 2008 No i only pulled 2 plugs, and the insulators on them looked a white'ish, brown colour. Will change the plugs tomorrow and report back.. Thanks again.. Quote Link to comment Share on other sites More sharing options...
n boost Posted January 23, 2008 Share Posted January 23, 2008 Have you checked all your intercooler connections? you will get a miss and black smoke if any are loose. I would change plugs as well. Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted January 23, 2008 Share Posted January 23, 2008 I would change the plugs as a precaution but i still cant see it being directly related given you dont have issued top end, just at certain specifics. Does it hold boost at WOT? As TTC mode didnt work and the boost controller is turned off im starting to wonder if its ECU related due to the specifics. Possibly an issue with the acel parameters. Quote Link to comment Share on other sites More sharing options...
chrisavila100 Posted January 23, 2008 Author Share Posted January 23, 2008 Have you checked all your intercooler connections? you will get a miss and black smoke if any are loose. I would change plugs as well. A new c/w smic was fitted in september, all piping has been checked visualy.. I would change the plugs as a precaution but i still cant see it being directly related given you dont have issued top end, just at certain specifics. Does it hold boost at WOT? As TTC mode didnt work and the boost controller is turned off im starting to wonder if its ECU related due to the specifics. Possibly an issue with the acel parameters. Yes it holds boost fine WOT, no boost problems at all! Im starting to think it could be related to, the crank postion sensor/throttle postion sensor, but then the ecu is showing no error codes:search: Just about to change the plugs so will let you know how i get on.. Cheers for the input guys... Quote Link to comment Share on other sites More sharing options...
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