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Discussion Starter #1
I don't post here often, but I need your help. I've been running a large single turbo on my sc300 for quite a while and have been an AEM user from day one. Obviously, the AEM is designed for wasted spark; so, I acquired a DIS4, Stealth/3000GT wasted spark igniter, and VVT-i coils from the IS300. I never had a problem with this setup and powered the car past the 700hp mark on a stock GE bottom end.

I recently swapped out the Stealth igniter for an IS300 igniter, and the darn thing now rev limits at 5k RPMs. The only difference is that I switched igniters! If I install the Stealth igniter, the car runs fine.

Here's my question: Does the IS igniter require some type of signal from the ECU to operate past 5K? I looked at the wiring diagram, and it has all the typical Toyota signals (3 IGT, 3 Coil outputs, +12v switched, ground, tach, and one IGF signal). The IGF signal should be the only "return" signal to the ECU. Is it possible the IGF is bi-directional? That's the only thing I've come up with.

I want to run a complete Toyota ignition and really want to dump the Stealth igniter because AEM informed me the input driver levels to the igniter transistors are different between Mitsu and Toyota.

Any help is greatly appreciated.

Thanks!
-scott
 

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That's really odd... I believe the IS300 uses the same ignitor as all the other later model 2JZ-GE's...

I can only suggest checking for coil dwell on the AEM and see if the ignitor is seeing too much current and cutting itself out. I also looked at the wiring myelf and doesn't seem to be bi-drectional nor anything different about it.
 

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Discussion Starter #3
That's really odd... I believe the IS300 uses the same ignitor as all the other later model 2JZ-GE's...
Keep in mind, my sc300 is a '95; it was originally a distributor ignition. I had such good success with the VVT-i coils, Stealth igniter, and DIS4 that it only made sense to convert the igniter to the IS igniter because it was designed to work with the coils. Plus, the coils are very stout. They're basically a two-post design that fit under the cam gear dust cover. TT coils do not. Oh... and on a side note, I'm using OEM plug wires, too; and they have worked flawlessly under 30+ lbs of boost generated by a T71. :)

I can only suggest checking for coil dwell on the AEM and see if the ignitor is seeing too much current and cutting itself out. I also looked at the wiring myelf and doesn't seem to be bi-drectional nor anything different about it.
Agreed... I'll play with coil dwell. That's a good idea. Thanks!

This really has me puzzled, and I appreciate the input.

-scott
 

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Discussion Starter #5
Lambchop/Tony,

Thanks for the replies... All help is appreciated. :)

So, I believe TonyTiger had the right idea. I cut the coil dwell in half, and it stopped rev limiting. With a CDI, a shorter dwell should be fine.

Here's why I believe no one else has experience this. I converted my distributor ignition to a dual-pole Hall effect using a modified aftermarket cam gear with rare earth magnets. I also modfied my AEM to accept the Hall output.

I've been running this setup for over 3 years, and it worked flawlessly until I installed the VVT-i igniter. As it turns out, the cam gear only has 12 crank triggers which is half of the number of OEM crank events; so, I had to cut all the crank teeth in half as well as the ignition and injector phasing in the AEM cal file. I did NOT, however, change the coil dwell settings to account for half the number of crank events per engine revolution. In other words, the max crank teeth for coil dwell is actually twice as long as the OEM dwell when the number of crank triggers is divided by two. At least that's all I think it could be.

Hopefully, this gets me past a very frustrating mis-fire. It's plagued me for about 6 months.

Thanks guys!
-scott
 
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