Kikih Posted June 17, 2022 Report Share Posted June 17, 2022 Hi all, we have a 2JZ GTE powered drift car, it has run off a G4+ Storm for the last four years with no issue. Two months ago it melted a piston, so it got a full rebuild. Our issue is since then it has melted two coil packs while on the dyno. We completely ripped the loom apart, checked every wire and could find no fault, so this prompted us to fit the new G4X Fury we had for it but never got to fit as you cant transfer the map. So our tuner created a map for the Fury from the map we had on the Storm, but the car wouldn't start, no spark or fuel. We had to give up on it and took it home. So we are now trying to locate the problem. We noticed the crank scribe was out of phase, it started downwards before heading up.. we swapped the pins on the Crank connecter and presto we had spark, but the car backfired into the intake. We know re timing it will probably solve that problem, but what is bothering me is why do we have to connect the crank sensor wrong to get it to fire, bearing in mind is ran perfectly when it was connected to the Storm. Anyone any ideas?? Also anyone with any idea why we keep melting the R8 coilpack on Cylinder 3, bearing in mind the 12V+, Ground, and signal ground are common to all six coilpacks, so the only wire that can single out a coilpack is the trigger wire? Thanks in advance for any replies. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 17, 2022 Report Share Posted June 17, 2022 Attach the triggerscope of it cranking. Your symptoms suggest the crank sensor was always wired incorrect polarity and no one noticed with the G4+. With the crank sensor wired the wrong way the cam sensor would sometimes cross over a crank tooth at a certain RPM or set of operating conditions and cause a loss of position. When the ecu has lost position it cant just fire a random spark at the planed time at an unknown position (some bad ecu's do!) Instead the ecu must stretch or shrink the dwell out until it re-establishes correct crank position and can fire that coil in the right place. This would usually happen right before or after the sync event - so likely always on the same cylinder - so this would explain the fried #3 coil. The G4X does further validations before and after every sync event and wont even fire a spark if not happy - so the inverted polarity would have been immediately obvious with the G4X. Quote Link to comment Share on other sites More sharing options...
Kikih Posted June 18, 2022 Author Report Share Posted June 18, 2022 Wow, thanks, amazing reply. How would this event present itself while the engine was running, would it misfire? would it be noticeable? The piston that melted was cylinder 3, do you think this issue could have been the cause? Finally, how would this cause the coilpack to melt, is it constantly triggering creating heat?~ Thanks again for the reply. I will get the trigger scope later today and post it. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 18, 2022 Report Share Posted June 18, 2022 13 hours ago, Kikih said: How would this event present itself while the engine was running, You would likely see significant timing drift when performing the ign delay test during trigger calibration, and I would expect in logs and on screen etc at some points there would likely be significant dwell scatter. 13 hours ago, Kikih said: The piston that melted was cylinder 3 Depends what you mean by "melted". Ign timing can cause knock - but this would usually break things rather than melt them. Melting is generally pre-ignition which can be caused by lean mixtures or something "glowing" in the combustion chamber such as an incorrect heat range spark plug or wrong head gasket bore size etc 13 hours ago, Kikih said: how would this cause the coilpack to melt, is it constantly triggering creating heat?~ The "dwell time" is how how long you have the ign coil "turned on" for. When the coil is "dwelling" the power you are feeding into it is being stored as a magnetic field. Eventually this magnetic field reaches saturation (with an R8 coil it is around say 3ms). Once it saturates then any further energy you put into it after that point is just making heat - it is not having any impact on the amount of energy stored in the coil. The longer you have it "dwelling", also means there is less time between each dwell event to cool. koracing 1 Quote Link to comment Share on other sites More sharing options...
Kikih Posted June 19, 2022 Author Report Share Posted June 19, 2022 Hi, these are the Trigger Scope files, thanks again for your help. TriggerScopeLog 3.llgx TriggerScopeLog start 2.llgx We actually had a hole melted on the sidewall of the piston, we had the injectors tested and they said there was a problem with injectors 1 and 3, problem showed up during the duty cycle. Its just cylinder 1 was fine but 3 was a mess.. I was just wondering were they connected. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 19, 2022 Report Share Posted June 19, 2022 Crank sensor is wrong polarity in these scopes. Quote Link to comment Share on other sites More sharing options...
Kikih Posted June 20, 2022 Author Report Share Posted June 20, 2022 Yes we copped that, thank you for your help, it answered all our questions. Quote Link to comment Share on other sites More sharing options...
Kikih Posted June 20, 2022 Author Report Share Posted June 20, 2022 Set the base timing tonight, car started and is now running well, next stop the Dyno and hopefully 650 to 700bhp.. Quote Link to comment Share on other sites More sharing options...
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