T2 MSW Posted February 22, 2010 Share Posted February 22, 2010 (edited) Had an odd issue for a while which I need help in fixing. Was most apparent when the car was recently on the dyno being mapped and the issue occured on almost every run but not when out on the road. Firstly I dont believe this is an issue related to being on boost, The car will do the same thing when just cruising and any speed but its completly random when it does it. Basically on cruise the car will loose all power and then a few seconds later its fine. It feels like the AEM is ripping all the timing. On boost (and when on the dyno) again the car feels like its ripping loads of timing away and it will severly backfire when on full boost ever so oftern. Ryan suggested the AEM was detecting a knock on the dyno and pulling the timing, Im sure he said he could hear it on the det cams too. He suggested the Ignitor may be on the way out but ive changed that and its not helped. Next on the list is to check the plugs one night this week but they are almost new. Check the coil packs but again they are all new and the clips same as the packs. Edited February 23, 2010 by JustGav (see edit history) Quote Link to comment Share on other sites More sharing options...
Geo Posted February 23, 2010 Share Posted February 23, 2010 better off sticking this in Technical bud, Quote Link to comment Share on other sites More sharing options...
JustGav Posted February 23, 2010 Share Posted February 23, 2010 Moved... Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 23, 2010 Author Share Posted February 23, 2010 Cheers Gav, no one seems to have any ideas though so this is going to be the shortest technical thread in history Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted February 23, 2010 Share Posted February 23, 2010 Didnt Ryan notice anything during the run, EGTs, AFR, timing changes etc? What condition is your ignition wiring in? I changed the coil pack clips on my Aristo the other week, ended up partially rewiring it because alot of the insulation had broken up on the coil pack loom. Might be worth stripping back the conduit and checking the state of the wiring. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 23, 2010 Author Share Posted February 23, 2010 EGT I cant say as thanks to a supplier in the USA I have no EGT readouts currently. The AFRs were uneffected. On the dyno it was detected as a knock and the AEM ripped the timing away, Im sure Ryan said he could hear it on the det cans too. But then it never did it on the road. Ill check the coil pack loom condition when I check the plugs tonight put from when the engine came out last year I checked then and it was in good condition. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 23, 2010 Author Share Posted February 23, 2010 (edited) Ok ive checked all the plugs tonight photos below and I can see any issues with any of them. However I have found one of the injector connectors I can get to is just placed on the injector connector. The wire is also bare from what looks like where something external connects into. Can you get injector connectors as replacment items and are they as easy to fit as the coil pack clips? Even with the above I dont think this its causing my issue, I fail to understand why if its an ignition problem i dont get just a missfire? I woudl have though it would miss and you would hear it and perhaps feel it alittle. When this occurs it feels something in the region of a RLTC hard cut. Edited February 23, 2010 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 24, 2010 Share Posted February 24, 2010 That connector dont look to good to me Still cant see it being the cause of this apparent 'missfire'. Im not realy convinced this is a missfire issue myself unless the AEM reconises a missfire as knock and pulls timing Input guys come on! Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 25, 2010 Share Posted February 25, 2010 What the hell is going on with that injector? From the picture it looks like there is a wire tapped into the injector wiring that goes off somewhere, but the insulation has melted?! If you've got a bad/overheating connection on injector #2 because of that, then chances are it is sometimes not openeing for as long as it should - runs lean, detonation. Or doesn't even open enough to get ignition, so misses a whole beat or two, runs on 5 cylinders. That nasty looking thing is where I'd start investigations. -Ian edit - is that a melted scotchlok?! Quote Link to comment Share on other sites More sharing options...
imi Posted February 25, 2010 Share Posted February 25, 2010 http://www.mkivsupra.net/vbb/showpost.php?p=2620351&postcount=8 Whats the deal with people using scotchloks when it seems like they cause more trouble than they are worth.... Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 25, 2010 Author Share Posted February 25, 2010 (edited) What the hell is going on with that injector? From the picture it looks like there is a wire tapped into the injector wiring that goes off somewhere, but the insulation has melted?! If you've got a bad/overheating connection on injector #2 because of that, then chances are it is sometimes not openeing for as long as it should - runs lean, detonation. Or doesn't even open enough to get ignition, so misses a whole beat or two, runs on 5 cylinders. That nasty looking thing is where I'd start investigations. -Ian edit - is that a melted scotchlok?! Cheers Ian, Believe it or not thats how the alarm fitters tapped into the igntion system. Its very next on the list to sort out this weekend. I have got a second hand loom from M_Life's car which he has kindly offered me the injector connectors from. Were going to chop it off and connect the wiring correctly. The clip is actually broken too and just sits on the injector, you can remove it with no effort what so ever. Even still I would ask the question would the injector not firing and missing a run maybe two cause detonation or a knock? Edited February 25, 2010 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted February 25, 2010 Share Posted February 25, 2010 The issue is a strange one and i would say either related to a problem somewhere in the ignition system or the valves (maybe sticky). When the miss happens it creates a nice knock in the engine which the aem detects are knock and then it pulls the timing back but this is after the event has occured. Saw this once before and it was a faulty ignitor but as thats not curred it i would looking into the following: Swap Dli with known good one and check earth is good! Check timing star on crank is secure and not loose Check crank sensor and cam sensors are securely tightened. Swap cam sensors around (only one is used by aem so will rule out fauly sensor) New crank sensor Finally check valve clearances Ryan Quote Link to comment Share on other sites More sharing options...
bluecoup Posted February 25, 2010 Share Posted February 25, 2010 not something stupid like a loose battery terminal or a evil earth somewhere mates scooby had a kick like fcd and was battery terminal Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 25, 2010 Author Share Posted February 25, 2010 Cheers for the input Ryan, so the loss in power is the AEM pulling the timing. Could you hear the knock when it was on the dyno? It did it on almost every run IIRC when we got over 1 bar? Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 25, 2010 Author Share Posted February 25, 2010 When the miss happens it creates a nice knock in the engine which the aem detects are knock and then it pulls the timing back but this is after the event has occured. Swap cam sensors around (only one is used by aem so will rule out fauly sensor) Are you reading the above M_Life, Sensor's lol Ryan do you know if the AEM uses the front or rear sensor? Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 26, 2010 Share Posted February 26, 2010 Even still I would ask the question would the injector not firing and missing a run maybe two cause detonation or a knock? Well I did cover it in my post, albeit briefly. Here's my thinking in more detail. Obviously the scotchlok fitting was a bodge, and the scotchlok itself has melted. Melting = heat, and the way you get heat with wiring like that is from too much current is going through too thin a wire. So this implies that the scotchlok has, in its own special way, cut through too much of the wiring. The injector works by opening when current flows through it. The more boost you run or the higher the rpms, the longer the injector is open for so the more current it gets over time. If the wiring is now thin because too many strands were cut, it'll heat up when the duty cycle goes up, and resistance will go up with it. This then means that not enough current reaches the injector and control of it goes haywire - it doesn't open long enough, not enough fuel goes in, too lean a mix, and the result is detonation. While it sounds like something Dr. House would come up with, it does actually fit all the symptoms - intermittent misfires, causes knock, nothing shows up in the datalogs. And you've got the smoking gun of the melted scotchlok showing that it's heated up significantly before... How's that for input Quote Link to comment Share on other sites More sharing options...
FireStormNBI Posted February 26, 2010 Share Posted February 26, 2010 if you have time, try to open your ECU and check if all components are ok.. it took me almost a year to find out whats causing the misfire on my supra, i already disassembled the dashboard to check the wire harness,changed my ignition coil, plugs, HT leads, distributor caps, rotor, until just recently out of desperation i opened my ECU, it was then that i found out there was 2 capacitors and 2 diodes that got fried.. check my thread.. http://www.mkivsupra.net/vbb/showthread.php?t=210732 hope this helps... Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted February 26, 2010 Author Share Posted February 26, 2010 Cheers for the detailed explination ian I sahould point out it's not a melted scotchlok it's that black goo stuff used to seal things. The actual wire is soldered on all be it very badly. I'll remove the alarm wire and fit a new connector this weekend. The alarm wire is the pickup for the antijax on the Clifford I believe and I can turn that off. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted March 1, 2010 Author Share Posted March 1, 2010 Well it's possible it is down to the injector connector. Removed the alarm wire and fitted a new connector (thanks m_life) few high boost pulls yesterday and drive about today and all seems really good so far Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 29, 2010 Share Posted April 29, 2010 Something jogged my memory about this thread, so I found it and have dug it up to ask - did swapping the connector and sorting the wiring end up being a permanent fix? -Ian Quote Link to comment Share on other sites More sharing options...
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