Issues with Split Second ESC1

[steezemcqueen]

A couple weeks ago i installed the Split Second ESC1 on my 97 4runner S/C. For the first couple days, everything worked fine. The video below shows what is currently happening.

To explain what the ESC1 does, here is the info sheet from Split Second
http://splitsec.com/products/datapdfs/esc1ds.pdf

"The ESC1 EGO Signal Conditioner alters the signal from EGO sensors under boost conditions. Under vacuum conditions, it outputs a signal which is identical to the EGO signals that appear at the input. Under boost, it outputs an internally generated signal to allow open loop operation."

Basically under boost, its richens the AFR so you make more power and have less chance of pinging.

However, mine appears to be doing the opposite. It worked fine for awhile. Then it started randomly leaning out the AFR's. I disconnected it a few days ago because i didn't want it to run lean. I reconnected it tonight and i can't get it to operate properly at all. I have double and triple checked all my wire connections and boost lines. It runs normal and does not lean out with the ESC1 disconnected and when i go full throttle, it still goes into open loop fine and doesn't lean out.

Here is the video. Yes i know its kinda long.
4runner split second ESC1 problem.

I know most people here 96-98 owners here are not supercharged and even less(if any) have or are familar with the ESC1. But i figured crossposting it here wouldn't hurt.

Anyone have any input?

[mastacox]

Welcome to the club buddy, it's a cold lonely place here haha

I have the exact same kit as you, the FTC1-E with the oxygen sensor circuit. I also had basically the same thing happen to me, it was a couple of years ago now. In a nutshell, the oxygen sensor bypass circuit on the FTC1-E doesn't work (nor does the ESC1 which uses the same circuitry I think). Why it doesn't work is the subject of quite a debate, my personal guess is simple:

• It isn't putting out an offset O2 sensor signal, it's putting out a constant voltage.
• The voltage it puts out isn't the "exact" one the ECU is looking for. If its a little too high, it will lean the mixture perpetually; if it's too low, it will richen the mixture perpetually.
• There's no way to fix this problem (IMO)

A couple of discussions you might be interested in:
Me building my own O2 sensor calibrator (works pretty well)
Steve and me bitching about the FTC1-E
Some unrelated issues I had with my spark plugs

Ask me questions and I shall answer as best I can, but I can't guarantee my guesses will be right lol I've got a new plan to further improve my personal oxygen sensor calibrator system using an Arduino microcontroller controlled with Bluetooth through my phone, but that's a little while down the road yet.

That being said, you might check out URD's own O2 Sensor Calibrator I hear it works, although be cautious because if it doesn't put out an offset oxygen sensor signal that changes with the ECU's fuel adjustments, it may have it's own issues. I personally think the offset signal using an aftermarket oxygen sensor is the best path, hence what I've done.

[steezemcqueen]

Thanks for your response Brian.

After reading through your thread, i think your setup seems to be the best route.

I have seen the URD O2 sensor calibrator and considered it. However, i can't really justify spending $220 on it when URD is selling the LC-1 kit for ~$180. Also, i haven't seem to find anyone running the URD O2 calibrator and saying that it works. I would assume it does work well because i doubt Gadget would sell something that flat out doesn't work. But he does still sell the ESC1

Anyway, i don't have a wideband yet so this would take care of 2 things at once.

Thanks for putting together a solution that works! I will probably copy it

Thanks again for your help!
Dylan

[mastacox]

Glad to be of help, wideband is a must for tuning and if you buy the LC-1 you're golden because then you've got what you need to copy my setup, which works much more reliably than the FTC1-E / ESC1.

It isn't perfect, transitioning from boost and out a couple of times triggers the switch on an off quickly and will make the ECU throw a CEL regarding bank 1 lean/rich. This is why I'm considering a microcontroller with a lookup table to smooth that transition, just haven't gotten to it (parts will probably cost around $100, not too bad). It seems to me that the only really "perfect solution" is to get rid of the Toyota ECU completely and replace it with a complete aftermarket system that utilizes wideband O2 for fuel control; that's really a lot more work than I'm willing to do though! Especially considering the whole gauge cluster goes through the ECU, plus trans shifts, etc etc etc...

Definitely post a thread & pictures of your own build when you do it, sorry I didn't answer you over on YotaTech but I'm not over there as much anymore since the "big change" in '06 or whenever it was. We've got a good group of guys over here though, stick around!

[steezemcqueen]

I emailed Mark at Split Second to see if there was a way to test the ESC1. Here is the response i got just for future info.

"Dylan,

Thank you for your inquiry. You can't directly measure the resistance of the ESC1 because it is an active device with amplifiers between input and output. You can test the device by grounding the input and measuring the output with a voltmeter set on AC volts. With power to the unit, you should read zero volts with the vacuum line open to atmosphere. You should read a small AC voltage around .25V with greater than 1 psi of pressure on the vacuum line.

The ESC1 is generally used along with a means of adding fuel in boost. There are different reasons why your engine could go lean with the ESC1. One possibility is that your ECU is adding fuel through fuel trim. If that is the case, the mixture will go lean because the ESC1 is taking away that trim. You can confirm that with a scan tool.

Let me know if you have any other questions.

Regards,
Mark"

[steezemcqueen]

Well i tested my ESC1 as Mark described above. I am getting a output that fluctuates between .3V and .8V. Basically what it is doing it generating a signal that is identical to what the ECU thinks is a stoich mixture. According to Midiwalls thread on CustomTacos, his ESC1 does about the same thing.

Granted I'm not a electrical engineer, but It doesn't make sense to me how this would richen the mixture. However, What Mark said in the email above does make sense because the ESC1 would feed the ECU a signal that would be a lean signal and the ECU would try and compensate and richen the mixture.

This definitely does not "force" open loop operation either. I think they need to reword their description of the ESC1.