michel lane Posted March 5, 2006 Share Posted March 5, 2006 I seem to be having some issues with the car when it warms up and comes onto boost. Today i started the car and it ran fine, came on boost to 14 psi , after about 10 minutes of fast acceleration i started to get a missfire , between 3000 rpm all the way to the top. So i checked the plugs and tried it again , it still missed . I then thought it could be my coil packs , so i went back and changed the coilpacks with ones i had laying around, took it out for a spin and the problem was still there. so i went back and changed the plugs for another set , took it out and the problem was still there. So i went home and left the car for about 1 hour while i had dinner , came out and noticed that one of the injector connectors looked abit doggy , so i rewired it and took it out . Well i was not getting any missfire at all ,i was well chuffed , but 10 minutes later it started again!! .. it seems to start missing when the engine starts getting a bit hot ... so any ideas anyone ??? I drove about 300 miles last weekend to get it tuned and and did not have any problems with it missing, but i was not running any boost , today i started going on boost and thats when the problem started.. things i have checked: 1:coilpacks - changed 2:sparkplugs -changed 3: DLI -checked 4:injector harness - checked replaced one i also noticed when you rev it , it does not miss at all , it only misses when you go on load ?? Link to comment Share on other sites More sharing options...
Markie Posted March 5, 2006 Share Posted March 5, 2006 O2 sensor? Link to comment Share on other sites More sharing options...
michel lane Posted March 5, 2006 Author Share Posted March 5, 2006 iam running AEM , WIDEBAND . Link to comment Share on other sites More sharing options...
TT-DEK Posted March 5, 2006 Share Posted March 5, 2006 HI m8. Sounds very similar to mine last week. Had mine on RR and up to 6k seemed fine. After this it seemed to miss like mad. Turned out to be my FCD, cause of work id had done recently. fuel and a few other things were all over the show. Had it tuned on RR for almost an hour. Purrs like a kitten now! Hope this helps. Pm Greg at T/Fit for more advise if needed. Link to comment Share on other sites More sharing options...
Ian C Posted March 6, 2006 Share Posted March 6, 2006 I very much doubt it's an FCD issue as Michel has a full AEM standalone Michel - how are your coil pack connectors? Especially if you've been changing the plugs and 'packs a lot recently are they getting a bit fragile? If it only misfires under load it's gotta be your ignition system. -Ian Link to comment Share on other sites More sharing options...
eyefi Posted March 6, 2006 Share Posted March 6, 2006 could be mapping, what are the afr readings? Link to comment Share on other sites More sharing options...
Ian C Posted March 6, 2006 Share Posted March 6, 2006 Spurious with a misfire, as unburnt or part-used fuel zips through the misfired chamber He'd have to be running 9:1 to get misfires, that's a big map glitch but it's worth investigating, I once typo'd a duty cycle cell to +100% lol -Ian Link to comment Share on other sites More sharing options...
Alex Posted March 6, 2006 Share Posted March 6, 2006 Could it be knock control? Does the AEM auto retard if it feels knock? Instead of a missfire as such could it be a stutter because of det? Seeing as it only happens on load etc... Link to comment Share on other sites More sharing options...
michel lane Posted March 6, 2006 Author Share Posted March 6, 2006 iam going to try the ignitor first and then check the coil packs , to see if it is this .... also i have a HKS DLI , the unit pulses as the car revs , is this normal , i thought the light was suppose to stay constantly on ..... Ill have a look at the coil clips aswell. I dont think its the knock but saying that it could be ... but if it was then it should happen when its cold aswell. ill keep you informed Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 6, 2006 Share Posted March 6, 2006 iam going to try the ignitor first and then check the coil packs , to see if it is this .... also i have a HKS DLI , the unit pulses as the car revs , is this normal , i thought the light was suppose to stay constantly on ..... Ill have a look at the coil clips aswell. I dont think its the knock but saying that it could be ... but if it was then it should happen when its cold aswell. ill keep you informed the led on the dli flashing is normal. as long as its not on/off type flashing. as soon as you pull the throttle cable that minor flashing should go away. it is vital to know the a/f ratios. post this and it will help. also, what bar of boost has it been mapped to? are you running any aem sensors like the 3 or 5 bar map sensor? i personaly think its a glitch on the map, if you want me to take a look at it then email me your map and i will take a look at it for you.... cherio. bijal Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 6, 2006 Share Posted March 6, 2006 sorry, just noticed, you have a 5 bar on your sig, double check wiring on that too. Link to comment Share on other sites More sharing options...
Ian C Posted March 6, 2006 Share Posted March 6, 2006 I just noticed your sig too, any chance it can be smaller?! And less colourful Jaysus. Anyway, I just noticed everything was apparently running fine: "I drove about 300 miles last weekend to get it tuned and and did not have any problems with it missing, but i was not running any boost , today i started going on boost and thats when the problem started.." So maybe it is the map I thought Michel had been mapping it himself -Ian Link to comment Share on other sites More sharing options...
michel lane Posted March 6, 2006 Author Share Posted March 6, 2006 you can map aem ??? can you map them using the GM BOOST CONTROLLER ?? and control meths ?....if s i need to callyou . do you use boost comp ?? or do it properly No Ian , i cant map for toffee..... i just play around with the programs ....i wish someone would give me a crash course in basic engine mapping so i can do the changes myself when i get the logs. michel Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 6, 2006 Share Posted March 6, 2006 I just noticed your sig too, any chance it can be smaller?! And less colourful Jaysus. Anyway, I just noticed everything was apparently running fine: "I drove about 300 miles last weekend to get it tuned and and did not have any problems with it missing, but i was not running any boost , today i started going on boost and thats when the problem started.." So maybe it is the map I thought Michel had been mapping it himself -Ian LOL!! does the sig hurt your eyes now mate (just changed it slightly) if it still does then put your sun glasses on and look guess it was a bit OTT right? anyways, enough of making people happy with my sig, lets try and help this poor chap with his problems...at the end of the day we've all been there and it can be really annoying.. Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 6, 2006 Share Posted March 6, 2006 you can map aem ??? can you map them using the GM BOOST CONTROLLER ?? and control meths ?....if s i need to callyou . do you use boost comp ?? or do it properly No Ian , i cant map for toffee..... i just play around with the programs ....i wish someone would give me a crash course in basic engine mapping so i can do the changes myself when i get the logs. michel yes mate, factory trianed. gm boost control is good, but i personaly prefer to use an external controller like blitz, greddy (personal choice mate) i try and keep things simple as and striaght foreward as possible, number 1 rule!! you cant learn these things over night, you need to invest thousands in traveling and getting qualified and gain experience....or else...kabooom!!! bye bye 2jz!!! anyways, yes, minor skills is easily attainable, like uploading maps, downloading maps. changes to settings if you know what they do. like i said, to help you out send me your map and if you have it, a log file when this problem occures. i can try and sniff something out for you if i find something obvious to me. email address: [email protected] when this miss fire occures, how bad is it? does it missfire to the extent where it seriously struggles to reach higher rpm or does it missfire very slightly? if you dont mind me asking, where did you have it mapped last? bijal Link to comment Share on other sites More sharing options...
Ian C Posted March 6, 2006 Share Posted March 6, 2006 LOL!! does the sig hurt your eyes now mate (just changed it slightly) if it still does then put your sun glasses on and look guess it was a bit OTT right? anyways, enough of making people happy with my sig, lets try and help this poor chap with his problems...at the end of the day we've all been there and it can be really annoying.. Lovely job, cheers Back to techie content -Ian Link to comment Share on other sites More sharing options...
michel lane Posted March 6, 2006 Author Share Posted March 6, 2006 well its not fully mapped as yet , i only took it up to 4000 rpm to make sure the wastegate opened . We took it down to thor and they had a problem with the wastegate , so i needed to look into it. I checked the wastegate to make sure it opened and it did , but the pipes to the boost controller was the wrong way round . I have a base map at the moment, and it was ok until 4000rpm when it built up boost , my previous turbo was a t78 and the new one is SP71GTS , I have not been boosting it over 4500rpm. On the drive back it seemed fine to 4000rpm. Its seems ok when the car is cold , but when i have been driving for about 10 minutes it starts to miss. So i think it could be the ignitor or even the coil packs as they get up to temp. There will be a ignitor arriving for me tomorrow to test with, that will eliminate the first section, then i will test the resistance of the coil packs before and after the car is warmed up. If that does not cure it , then i will look at the map. Link to comment Share on other sites More sharing options...
eyefi Posted March 7, 2006 Share Posted March 7, 2006 Spurious with a misfire, as unburnt or part-used fuel zips through the misfired chamber He'd have to be running 9:1 to get misfires, that's a big map glitch but it's worth investigating, I once typo'd a duty cycle cell to +100% lol -Ian probably a combination of bad cell refrences multiplied by fuel vs air temp and fuel vs coolant temp modifiers and god knows what else. Link to comment Share on other sites More sharing options...
Wez Posted March 7, 2006 Share Posted March 7, 2006 Could this be somehow part of the warmup enrichment map. When the water/inlet temps are below a configured level the ECU will add additional fuel, so the question is was the car mapped from cold or once it was at full running temp? Link to comment Share on other sites More sharing options...
michel lane Posted March 7, 2006 Author Share Posted March 7, 2006 you got a point there .... Link to comment Share on other sites More sharing options...
Stevie Boy Posted June 19, 2006 Share Posted June 19, 2006 Did you get to the bottom of this misfire Michael? I've had and ongoing intermittant miss under load haven't really done much to try and diagnose it as it's so itermittant but when it does you know about it. I've bought one new coil pack and systematically trialed in each cyl, still there. Replaced low milage Iridiums with NGK-BKR7E gapped to 0.8mm, still there, tried another extreme and gone to 0.5mm (just as experiment) think it's still there and now idles not too smooth so i'll pulling plugs out again when i get a chance, to regap to 0.7mm and see what happens. I,m suspicicious of my Ignitor pack as when it miss's it feels like more than one cyl, no ECU fault codes to go on either, have an E-Manage Blue but have to have faith there's nothing wrong with that. Can't find any data to test Ignitor pack and every keeps telling me they don't go wrong, was wondering if you've sorted yours out yet?? Link to comment Share on other sites More sharing options...
Stevie Boy Posted June 19, 2006 Share Posted June 19, 2006 Does AEM use stock Ignitor Pack by the way? Link to comment Share on other sites More sharing options...
Lucifer Posted June 19, 2006 Share Posted June 19, 2006 Yes it can do. Link to comment Share on other sites More sharing options...
b_have Posted June 19, 2006 Share Posted June 19, 2006 I had a wierd misfire under load which was due to upping the fuel pressure (stretching 550s) Remember that a misfire will make afr logs nonsence (can show leaner than actual) so maybe you are running rich? Link to comment Share on other sites More sharing options...
LeeT Posted June 20, 2006 Share Posted June 20, 2006 I had a wierd misfire under load which was due to upping the fuel pressure (stretching 550s) Remember that a misfire will make afr logs nonsence (can show leaner than actual) so maybe you are running rich? very true, thats what caused my misfire. A sticky injector which eventually became a stuck open one. RICH on one cylinder and lean on the other five Link to comment Share on other sites More sharing options...
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