Ecu Question

[e10-sportif]

hi what would happen it a took an ECU from a 1.6 and placed it in my 1.3i sportif?? any1 know if it wud improve the BHP or just not work??

[RedNeck 92 Gti-16]

So you want to tune up ya sportif :P

But, you dont want to spend megabucks. You want to tweek it, to be sure. If you can find some part to swap that will improve what you have, thats using your initiative.

I like your idea. 'Get a sh@t hot re-map, by swapping ECU's' I've got a few 4AGE 1.6 16v ones if you want one....

As to swapping a 1.6 ECU, i dont think so. 'The brains', as it were. Are set specifically for the components found in your cars mechanics. Physically the connectors may not match, and so on.

Some cars have restrictive programming i.e, they may be restrictive in order to make things last longer. Particularly turbo cars, where boost levels are set low.

The 1.3 ECU is not probably not the place to look for releasing those horses!

[4afte]

i agree unless your planning to use a 4E-FTE from a starlet turbo? don't waste your money on N/A tuning the 1.3, i'd seriously reccomend saving for either a faster car to begin with or a 4A-GE engine conversion and there's no way the 1.3 engine will work from the 1.6 ecu, just telling you now, the engines are setup entirely differently.

[e10-sportif]

thnx for the info guys, what car u think i should get? ive been told a celica gt 2l engine will fit into my corolla and ive also found a site where people and done it so this could be a change to the glanza gt / starlet gt engine what you think?

[4afte]

3S-GE (or and of the S series) would fit in the engine bay, however you need to fabricate your own engine mounts, wiring loom and exhauset setup, whereas the starlet turbo engine will pretty much drop straight in (well not quite that easily but far easier than a 3S-GE (the 2L from the celica).

[ae111sr]

thnx for the info guys, what car u think i should get? ive been told a celica gt 2l engine will fit into my corolla and ive also found a site where people and done it so this could be a change to the glanza gt / starlet gt engine what you think?

If you want to go down the 3SGTE route you will need very deep pockets - my 4A-GZE conversion has been expensive enough - it's only been three years and I'm not finished spending yet

[4afte]

how much do you reckon you've spent overall on your conversion so far then ae111sr?

[RedNeck 92 Gti-16]

Got it!!

Youre going to like this, but not a lot.

You can replace the 1.3 sportif ECU with the one from the 1.6 Gti...

You just have to bring the rest of the car aswell!

The Corolla GTi is an awesome motor, even in standard trim. Its a little race car!

I'm sure you wont be disapointed. Just make sure you get one without rust issues.

[Rockerrock]

Try doing a air/fuel mod. Posted below.

• The ECT mod (Engine Coolant Temperature)

• Dr. Zhivago's ECT mod

Power. We can't just get enough of it, and of course, we don't want to pay anything for more of it. :)

Dr. Zhivago from the YotaTech forums has brought to light a trick that he tells me has been around for a while.

This mod produces more power by causing the ECU to think that it's dealing with a cold engine. To deal with this, the ECU will richen the air/fuel mixture to compensate for the cold, thus getting more fuel into the cylinder, thus allowing more power to be produced. A side effect is that as the ECU increases the amount of fuel that the injectors shoot into the engine, it will also advance the timing to be able to burn the additional fuel.

What's done here is to insert a 500 ohm "pot" (potentiometer, variable resistor) in series with the ECT sensor (Engine Coolant Temperature) and it's associated ECU input. When the pot is adjusted such that it's resistance increases, the voltage that's presented to the ECU will increase, and this will make the ECU think that the coolant temperature is lower than it actually is. The end result is that the ECU is fooled into reacting to a "cold" engine.

But, since the engine is actually warm, then we get more power from a cleaner burn closer to the optimum crank position and having more fuel in the mix. The net result is that you'll get better off-idle response and more pull throughout the midrange.

Cool huh? :) See this PDF paper for more info on how the ECT works on our vehicles.

Also be sure to check out the thread on YotaTech about this mod.

On to the mod!

• Taking out the glove compartment

Two philips screws Three 11mm bolts (there's A sneak peek at the ECU

another on the left)

In order to get clear access to the ECU, you'll need to pull out the glove compartment.

Remove the door by taking out the two Philips screws that attach the hinge, if you leave the compartment closed and latched at this point, it'll make things easier. Then unlatch the door and set it aside.

Drop the upper part of the frame by removing three 11mm bolts. The frame then comes out by pulling in on the sides and dropping it away from the dash. You may find a couple of wire bundles attached to it as well as the lamp for the glove compartment. Disconnect these from the frame, and put the frame aside with the door.

NOTE: You may find a yellow harness on the left side of the frame. If so, do NOT disconnect the plug, only remove it from it's holder on the frame. This is the connection for the passenger side air bag and you don't want to run the risk of forgetting to reconnect it.

• Finding the right wire

The ECT sensor junction The ECU Plug "B" Pulled

None of the wiring diagrams I had for my '96 Limited were correct when it came to documenting where the ECT sensor was wired into the ECU. With Dr. Z's help, I found the ECT sensor junction under the hood and used a ohm meter as a continuity tester to find the other end at the ECU. For my truck, this ended up being a Green/Red wire at position B21 on the ECU. It is highly likely that your vehicle will be different.

There are four ways to find this wire:

1. A valid wiring diagram

2. Using an ohm meter/continuity tester to trace the wire

3. Visually ID'ing the color of the wire under the hood

4. Searching the ECU connectors for a voltage that drops as the engine warms up

Option 1 of course is the easiest, but you'll want to check it with one of the other methods just to be sure. I figured that one of the three diagrams I had were correct, and I'm glad that I double checked!

Option 2 is the most absolute. Find the ECT sensor under the hood. It will have two wires going to it, most likely a brown wire (common ground) and then a Green/??? wire. Attach one lead of an ohm meter to the Green wire - if your ohm meter has a continuity setting, turn it on. Doing so will cause the meter to emit a "beep" when the resistance drops to zero.

Head for the ECU, and remove the first plug. With the other lead from the ohm meter, test each position of the plug that has a wire in it. You should be able to get the tip of the lead into the back of the plug far enough to make contact. You may have to push a bit, so don't be too shy.

Test each pin position while listening for the "beep" from the meter, or watching for the resistance to drop to zero. If the first plug doesn't turn up any hits, then put it back into the ECU and move on to the next. Keep trying until you find the wire... It has to be there somewhere! :)

The 3rd option above is "pretty" valid, but it can produce false positives. On my truck, the lead to the ECT sensor has a junction right as it comes off of the harness. In my case, it was easy to see the wire coming from the sensor up to the connector, but not from the connector to the harness. It is very important that if you're going to visually ID the wire that you make sure you're looking at the harness side, not the sensor side. The reason being that (on mine) the wire color on the sensor side was Green/Yellow and Brown - but the harness side was Green/Red and Brown! Making a mistake here will cause you to clip the wrong wire at the ECU. Be careful!

Option 4 works, but can take some time hunting for a single dropping voltage across all the connectors. You might also mistake what may be the ECT wire for something else that reacts the same way such as the intake air temperature. This option is best used as a validation for one of the other two.

• Splicing at the ECU

Splice complete!

Once you've ID'd the right wire, it's time to splice the cable that will run from the ECU to your control.

Take a deep breath and cut the cable at the ECU. Remember to leave yourself enough wire on both the plug side and the harness side to be able to work with. The harness is quite tight at this point and doesn't offer up a lot of slack. Tug on it a bit to get as much play as you can.

Attach the new cable from your control into the wire that comes from the ECT sensor to the ECU. Technically, it doesn't matter which side of the ECU/harness wire goes to which wire of the control. You can use crimp-on butt connectors here, though I prefer to solder the connections and dress the results with heat-shrink tubing.

• Installing the control

Pot, 1k resistor, knobs Pot layout Installed!

I chose to locate my control in the center compartment so that I could make on-the-road tweaks. So, I ran a length of 18 gauge two wire cable in a sheath from the ECU location to the console.

Wiring to the pot is straight forward. A potentiometer has 3 lugs on it, numbered above as "1", "2" and "3". The center lug (#2) is the "wiper" and this is connected to the part that moves inside the housing when you turn the shaft. For our uses, we want the resistance to increase as we turn the knob clockwise, which will happen if we use lugs #2 and lug #3.

When I went shopping for a pot, the lowest value I could find in the physical format I wanted to use was a 1k part. While this will work, it creates a very coubik control. To counter this, I used a bit of electronic theory to reduce the effective max resistance of the control to 500 ohms. Without going into the science behind why this works, it can be done by simply wiring a 1/4 watt 1k resistor across the outter lugs (#1 and #3) of the pot.

With that done, I soldered the end of the cable from the ECU location to lugs 2 and 3 (technically, it doesn't matter which wire goes to which lug) and then mounted the pot in the console. Once the pot was mounted, I attached the knob and called it good to go. :)

• Dialing in the mod

To configure the mod, all you need to do is:

1. Set the new control to the full counter-clockwise position. This will effectively "disable" the mod.

2. Start up your rig, and let your engine come up to normal operating temperature.

3. With the engine idling, turn the control clockwise (slowly!) and set the idle about 200-350 RPM above the normal. So, if you usually idle at 700 RPM, set your new idle to 900-1050 RPM.

4. Go drive! Tweak the control a bit, and experiment to find the biggest kick. Remember to set the idle with your rig in Neutral or Park so that you maintain a consistent baseline.

• The Results

Baseline: Idle at 700 RPM Idle set at 900 RPM Idle set at 1050 RPM

The pics show the results as viewed on a BR-2 OBD interface. Each pic is a screen shot taken while the truck was running at 2500 RPM in Park, i.e., a no-load condition.

Starting at the baseline (idle=700 RPM, temp=185) note the "Short-term fuel trim percentage" which is -1.6%. As the control is adjusted to add more resistance, you can see a couple of things happening:

○ The coolant temperature decreases

○ The idle speed comes up (hence the labeling of the screen shots)

○ The short-term fuel trim increases

The latter point is what you're interested in. As this percentage goes up, that means that more fuel is being shot into the engine. More fuel can give you more power.

The greatest increase I saw was around "idle = 1050". The short term percentage bounces around a bit, so it can be hard to get a solid upper-bounds. The 3.9% number was pretty consistant at this point - that's a real increase in fuel flow when compared to the root -1.6%!

Numbers are always good to see, but the real test comes from the official seat-of-the-pants meter!

For me, I found the largest changes when I kicked it at highway cruise speed - such as when pulling out to pass, or just playing around. Also, merging onto the highway is a better experience overall, with a nice smooth and consistant pull from 2200 RPM up to the shift points.

My gut feel tells me that there's more snap when coming off the line, but I need to do some more playing to get a better idea of just "how much". One nice thing about this mod is that it's quite easy to trim on-the-fly, or to turn off altogether for comparisons.

Thanks Dr. Z!

If you have any questions, you can find me on the YotaTech forums as "mpulver", or drop me a line directly at mark@midiwall.com.

Have fun!

Mark

Pasted from <http://www.midiwall.com/4Runner/ect.html>

Tech Article Title Author Date

Oxygen Sensor Modification Keman 2004

Drugs for your oxygen sensor. Well, not really.

This modification very cheaply fools your secondary (post pre-cat) O2 Sensors into thinking that there is actually a lot less oxygen present than there really is. Why would you want to do this modification?

1. You're running rich

2. Your oxygen sensors are on the fritz.

3. You gutted your precats, took out your main cats while you were at it, didn't want to buy a chip and got tired of that dumb check engine light staring you in the face.

(Not that I'd ever do something like #3. I'm a law abiding citizen and millions of whales would die if you removed your cats. Shame on you! Hehe)

Disclaimer: While I am an Audi technician the modifications listed here are not endorsed by Audi. I provide these instructions based on my own findings and experiments conducted outside of Audi of America, using my own tools in my own garage. If your car blows up after you perform this modification, don't go running to my dealership expecting me to fix it for free. They won't, and I will refuse to acknowledge that anything posted here was created by me.

SO.. You removed your precats and got the dreaded "Precatalyst efficiency below threshold" ... well this will fix it. Chances are you're reading this because you're too cheap to buy a chip that would eliminate this problem (like me), and also too cheap to have purchased WAY overpriced downpipes that have secondary O2 sensor bungs that are behind the main cats. Or maybe you did buy those expensive downpipes and got rid of the main cats too.

The first mistake people often make is trying to trick the ECM by using a resistor inline on the O2 sensor. After all, the "post catalytic" O2 sensors are now outputting 0.95 volts instead of an expected 0.1 to 0.8. A resistor of value X, where value X is whatever your friends brothers son's nephew runs on his Honda with 100% success. The problem is our ECM uses a mega-ohm measurement device, meaning just about no matter what kind of resistance you put in, the full amount of voltage will still be seen. Remember, resistance does not drop voltage, it limits current. If the ECM were to apply a decent load, then resistance would inadvertently drop the voltage it saw. So this is the right idea, but the wrong method.

Next mistake I've seen is a complicated circuit that takes the O2 sensor signals, processes them, and re-transmits them at a lower value. Geeze!!! Talk about overkill. While that will work, how about the most simple and cheap design possible.

1 Standard Diode from radio shack, P/N: 276-1141

The average rectifier diode is a one-way valve. It has a voltage drop when current passes through it, which for the sake of discussion is usually around 0.5 volts. There are millions of different diodes that can greatly alter that figure, but for our purposes we will use that figure because it's exactly what we need. Your precats aren't burning off any of those unburned hydrocarbons when they're laying in a million pieces in the trashcan, so there is plenty of oxygen present as far as the downstream O2 sensors are concerned. They're putting out 0.95 volts. Pass through this lovely $1.29 incarnation, and whee! It's 0.45 volts. What does the ECU expect? 0.45 volts is within perfect specifications.

Common misconception:

- The ECM measures the difference between upstream and downstream and calculates mixture based on that.

Bzzt! Wrong. Maybe on some cars, but not on ours. Those downstream sensors serve only one purpose: Measuring the efficiency of the precats. They honestly don't even measure the main catalysts! Cats age and lose some efficiency over time. If the precats aged and the air/fuel ratio was based off of this, you'd eventually run pig rich or your engine would lean out and predetonate itself to pieces under boost. That would be bad, and stupid. The primary O2 sensors do a perfectly fine job measuring the A/F ratio results.. And that's what they do. We're not going to touch them.

What we are going to do, is touch the post pre-cat O2 sensors. I have to call them that, because they're BEFORE the main cats, but AFTER the little pre-catalysts. Specifically, we're going to modify the wiring harness of the sensors themselves. That way if you decide you want to change back to completely stock, you can just put a new O2 sensor in and the wiring comes with it.

Audi was nice and put the harnesses on the passenger firewall HERE. Green and Brown are your friends. Don't touch the black connectors, those are your good O2 sensors and that's where the real magic of the engine is contained.

Which connector is what?? The side you want to be modifying has pins in sticking out of the connector. If you see flat pins, you're cutting into the sensor side of the harness. If you see 4 flat slots for pins to go into, you're cutting into the ECM side. Bad!

As you can see in the picture, I slid back the rubber boot and cut the BLACK wire. This is the O2 sensor (+) output. Grey is reference voltage, and both whites are the heater circuit. Cut the black wire, crimp in the diode with the silver bar facing the ECM side (towards the connector). If it's backwards, your ECM won't see any voltage at all. So if that happened, now you know why.

Make sure you cut enough of the wire to make up for the length of the conglomeration. It's about 1.5" if you use two crimp connectors and cut the diode leads to about 0.5" long. Bonus points if you heat-shrink this connection, but with the rubber boot slid back around it I really don't think you'll have any corrosion problems here.

Remember, silver bar on the edge of the diode is on the ECM side, not the sensor side. This allows positive voltage to flow from the sensor through the diode to the ECM.

Repeat for both the brown and green connectors (left and right post pre-cat O2 sensors)

And when you're done, the voltage drop occurs and all is good. Clear those codes and enjoy!

Pasted from <http://www.audiworld.com/tech/eng53.shtml>

[ae111sr]

how much do you reckon you've spent overall on your conversion so far then ae111sr?

More than I'm willing to admit to. I had a few wild goose chases and spent money on things which just didn't work out - Unichip, suspension, and some other stuff. I've done things to suit me - not what other people think I should have done. I didn't need to buy SPA gauges, Momo steering wheel, two sets of alloys, MR2 front seats - I could go on. But having said that my car is unique. I know of two other AE111 4A-GZE conversions in the UK and none of them is the same. Knowlson had one, which he sold, and there was Carl from Norfolk way whose Corolla was dressed with decals to look like a WRC car - he sold his as well. Each had different suspensions set ups, air intakes, body kits etc. and each looked different. Take a look at my entry in the registry on here for more details or if your really really interested take a look at ae111sr.co.uk for almost everything that has been done to my Corolla since I bought it new way back in 1998.