Mods

[topless87]

Has anyone done the ECT mod? Not sure if im comprehending the instructions right. Was wondering if i could get some pointers, or is it even worth doing.

 

[Aelfwine]

Why haven't I heard anything of this mod? I just looked it up and am tempted to do it!

Heres a link.
http://www.midiwall.com/4Runner/ect.html

 

[Robb235]

It's total BS. I tried it a while back, and it doesn't do anything meaningful. Even the author's "proof" of it working is a bunch of nonsense. I started a thread on another forum with my observations, here is my post:

Back when I owned my '97 4Runner (before some idiot smashed into it in a parking lot) I ran across the ECT mod, and liking the idea of being able to bump up timing slightly, I installed it. The idea is that by installing a variable resistor, you can fool the ECU into thinking that the engine is colder than what it actually is. With the engine being cooler, theoritically the engine will advance timing and also inject a little bit more fuel for an increase in power. Instructions can be found http://www.midiwall.com/4Runner/ect.html and http://www.yotatech.com/f130/engine-...ect-mod-75163/

The author of this mod "proves" that this works by showing before and after pictures of engine data, where by having the mod dialed in, the short term fuel trims (STFT's) are slightly higher.

This is all garbage.

First, anyone who's ever put a scan tool on their vehicle and looked at the STFT's can see that the STFT's are constantly bouncing around. Even when the vehicle is not moving and is just idling in the driveway, the STFT's are constantly changing. When I had this mod on my '97, the STFT's bounced around between positive and negative just as much as when the mod wasn't in place. In fact, I don't even think the STFT's are what you should be looking at, you should be looking at the Long Term Fuel Trims.

I've taken my 4Runner on the highway (tried different speeds from 50 to 80) and my LTFT's aren't any different than when the mod is zero'd out (ie. back to stock). I also noticed that there is no difference in timing advance either.

The author claims a "seat of the pants" increase, and claims this is caused by more fuel and an increase in timing. However, I have an alternate explanation. Several years ago I owned a '95 Chevy Monte Carlo that sprung a small vacuum leak one day as I was sitting in traffic. A small vacuum line had popped off and my idle speed went from ~700 RPMs to around `1,500 RPMs. The cool thing about this was that the car "felt" like it had more power when pulling away from stop lights. Did the car actually have more power? No. But the vacuum leak was raising the engine speed making it feel like it did when I was barely touching the gas pedal.

The same thing is happening with the ECT mod. However, instead of a vacuum leak, the modified ECT signal is causing the ECU to open up the Idle Air Control Valve more, raising idle speed. You're not getting more power out of the engine. You're just pressing the gas pedal a little bit more in a round about sort of way. Want the exact same effect that this mod produces, but without splicing in a variable resistor? Press the gas pedal a little more.

These are just my observations. Feel free to discuss.

http://www.yotatech.com/f2/ect-mod-observations-266907/

 

[98OzarksRunner]

Even if the mod worked (and as the post above notes, the ECM is always correcting the mixture based on feedback from the O2 sensors, so any real effect would probably only apply at WOT), it would likely have the opposite effect. It is common knowledge among tuners that leaning out the mixture slightly gives the most power, not richening it. The only reason to richen the mixture at WOT is to avoid detonation, usually required with forced induction (superchargers/turbochargers). The goal in high-performance engines is to run the mixture as lean as possible without detonation at WOT (has to do with flame travel speed and other technical stuff - an A/F of 1 point rich [from ideal] will usually cost 10% power). It will also probably increase cylinder wall and piston/ring wear as the extra fuel washes oil off the cylinder walls. The most wear on the engine occurs during the warmup period, largely due to running a rich mixture when it's cold. If the mod fooled the ECM into thinking the engine was not warmed up completely, it might run in open-loop mode, which will make it run rich all the time, and probably use lots of extra gas, with lots of extra wear. But, as the quoted post above says, he tried it and it didn't do anything (presumably the ECM corrected for it - as it should).

 

[AZ4Running]

Yeah total joke. Freeze frame of engine data in the write up shows and proves nothing. Fuel trims and ignition advance change on the fly all the time. Dyno results would tell the true story. Also adding more fuel on its own will not make more power just decrease economy. You need to have more air along with the additional fuel to increase power output.

 

[topless87]

Yeah did not make sense to me. From what i was reading states that the temp sensor adjust timing and fuel. But like previous stated here O2 does most of that mixture. And to me if vehicle dumps more fuel this requirs more air? I think i may need to replace my injectors anyway. At idle seems to feel like it misses but when i hooked up my Snap-on Solus Edge no miss fires detected and all injectors are pulsing. I think they may be clogged. Any ideas on what else may be doing that?

 

[AZ4Running]

Yeah o2 sensors, maf sensor and coolant temp sensor give the ecu data to adjust the fuel trims and timing advance. The ait sensor does also but not nearly as much as the others do. The onky want to get more power other that basic bolt ons like ihe or supercharger is to tune the ecu. Sadly there is not much out there for tuning our 4runners. There is unichips but thats about it. Not even sure if toyota can reflash the dcu for more power. Tuning permanently changes the fuel and timing maps to optimum specs to get the most out of the motor. Stock tuning is pretty conservative and for best economy. For example my civic with b18b1 non vtec swap with ihe made 117whp 115lbft on the stock ecu. After dyno tuning it made 131whp 127lbft with nothing else done except remapping the ecu. With vtec head it made 161whp and 127lbft. Point is tuning is the only way to increase power not resisitors on the temp sensors or maf sensor.