This is half info half venting..skip to the end for cliffs..
For year now i have been having problems with blowing out spark and having to run such a small plug gap that i'm losing power.. So fast forward a couple of years when i help my friend swap a 1jz into a supra.. through my knowledge of blowing out spark, i helped him the best i could.. well through a mutual friend who works on mainly chevy's, we learned that ls truck cils are good for up to 300+hp per cylinder.. after he went standalone, he swapped in ls coils in his supra and opened up the plug gap.. the difference as beyond day and night. It idled perfectly and ran ike a scalded ape.. such an improvement that i always said i would do the same to my truck when i could.. well after rebuilding my engine and fixing about everything else, i decided to go for it.
So i ripped out the harness, and soldered in the ls coil harness.. well it started up first try and ran for a whopping 2 seconds before dying.. and the same again and again and again. Through my research i discovered several things.. first is that the ls and toyota coils have completely different feedback signals to the ecu. the toyota coils use a flat pulsed signal, these signals are known as igf signals. .. the ls coils have a more peaked grounded signal..
So ls coils did not work on the stock ecu as is. more and more research led to mostly supra owners running e-manage piggybacks, having a problem with the igf signal not being generated due to the ignighter being bypassed.. so after reading through it all i saw that some had made a chip using a npn transistor to take the coil firing signal and through the transistor , create a igf signal and feed it back to the ecu.
so after making the same chip myself, i installed it.. and it did not work at all for me. i tried switching up several things.. After three weeks of trying everything i could try and with no success, ive soldered back in the stock coils..
I must say though that i feel gutted.. ive never worked so hard and long on something to fail in the end .. the sad part is that th coils would run just fine given the ecu wasn't so pissed off at the igf signal..
The only good news in all of this being that i'm going to convert to a standalone at the first of the year and this problem will be a distant memory.
so in closing, if you every think of running ls coils, good luck to you
Cliffs: Tried to run ls coil's on the stock taco ecu.. tried everything, it didnt work out.