The Free Mod Series - Part III Tuning the ECU
07-02-05, 07:00 PM
#1
Lexus Champion
Thread Starter
The Free Mod Series - Part III Tuning the ECU
Background:
Toyota engine's run notoriously rich from the factory. I don't care what engine you place in front of me. If It's an EFI Toyota engine, it's nearly a default that it will gain 10 horsepower by simply leaning the stock fuel out at the upper rpm ranges.
Theory
Some ECU's can do it with a new chip / flashing. Some can do it with a piggyback (intercepting the signal, and sending a new- modified one). VZ engine owners happen to use the old vane-flap style air-flow meters. The good news, is that unlike the later MAF's, they are the same, or slightly less restrictive than most similar size MAF's, while being adjustable!
Instuctions
Start buy pulling the EFI fuse out of the fuse box by the battery. Count to one, and replace it -- The ECU has been reset.
2vz, and 3vz-fe owners. This is your Air-Flow Meter. (2vz-fe AFM's are much smaller)
Cut the silicon that glues the plastic top off an dyou see this.
At this point, you need to make a permanent mark on the cog so you don't forget where it is... Sharpie, score it - I don't care...
Here is the cog, which keeps spring tension on the flap.
Self explanitory. Clockwise = lean, Counter-clockwise = rich.
Unless you have very serious engine mods... I'm talking head porting and a y-pipe at LEAST, you have NO business adding fuel to the mixture (going richer).
What you should know is that you will NOT get a gain in throttle response... Throttle transitions are richer than maximum power is achieved. -- The end result is that if you rev the engine in park, don't be surprised if it revs slightly SLOWER than before - because it is leaner. Do your testing on the road where there is a load on the engine. You will feel more power.
********************************************************************************
Background:
Ignition timing. It's a great tuning tool! If you time the explosions correctly, you'll achieve peak power! Too early will reduce power - Way too early will cause the pressure wave to strike the piston on it's way up - leading to varying degrees of detonation (knocking, pinging - all the same thing) and eventually engine damage. Too late will have the mixture waiting around - way too late will have the mixture burning in the exhaust manifolds!
Theory
VZ block engines have a distributor which sets the base ignition timing. The factory timing is 10* btdc on piston #1(rear head, passenger most side). For whatever reason... Many cars that came from the factory have slightly retarded timing, in the 7-8*btdc range.
Instuctions
The distributor is located under the intake manifold. it is held to the rear cylinder head by two 12mm bolts. Loosen them a few turns - enough to hold the distributor on, but loose enough to turn it!
The 1992-1993 3vz-fe is highly resistant to detonation because of very weak factory tuning. With a timing light and the ECU in diagnostic mode (jumper E1 and TE1 in either Diagnostics port). Set the timing to 17*btdc. There should be no reason to run higher grade gas. Continue to run 87 octane.
1987-1991 2vz-fe should start at 15*btdc. There should be no reason to run higher grade gas. Continue to run 87 octane.
There may be a 3hp - possibly 5hp peak gained, much better throttle response, and a very small mpg boost from adding ignition timing.
*****************************************
Part I Quicker Transmission Shifting
Part III Tuning the ECU
Part IV Cooling
Part V How to pick up MPG, and sleep with her too!
Part VI Acing Aerodynamics
Part VII Cheap Water Injection
Part VIII Cheaply Monitoring the ECU & A/F Ratios
*****************************************
Toyota engine's run notoriously rich from the factory. I don't care what engine you place in front of me. If It's an EFI Toyota engine, it's nearly a default that it will gain 10 horsepower by simply leaning the stock fuel out at the upper rpm ranges.
Theory
Some ECU's can do it with a new chip / flashing. Some can do it with a piggyback (intercepting the signal, and sending a new- modified one). VZ engine owners happen to use the old vane-flap style air-flow meters. The good news, is that unlike the later MAF's, they are the same, or slightly less restrictive than most similar size MAF's, while being adjustable!
Instuctions
Start buy pulling the EFI fuse out of the fuse box by the battery. Count to one, and replace it -- The ECU has been reset.
2vz, and 3vz-fe owners. This is your Air-Flow Meter. (2vz-fe AFM's are much smaller)
Cut the silicon that glues the plastic top off an dyou see this.
At this point, you need to make a permanent mark on the cog so you don't forget where it is... Sharpie, score it - I don't care...
Here is the cog, which keeps spring tension on the flap.
Self explanitory. Clockwise = lean, Counter-clockwise = rich.
Unless you have very serious engine mods... I'm talking head porting and a y-pipe at LEAST, you have NO business adding fuel to the mixture (going richer).
What you should know is that you will NOT get a gain in throttle response... Throttle transitions are richer than maximum power is achieved. -- The end result is that if you rev the engine in park, don't be surprised if it revs slightly SLOWER than before - because it is leaner. Do your testing on the road where there is a load on the engine. You will feel more power.
********************************************************************************
Background:
Ignition timing. It's a great tuning tool! If you time the explosions correctly, you'll achieve peak power! Too early will reduce power - Way too early will cause the pressure wave to strike the piston on it's way up - leading to varying degrees of detonation (knocking, pinging - all the same thing) and eventually engine damage. Too late will have the mixture waiting around - way too late will have the mixture burning in the exhaust manifolds!
Theory
VZ block engines have a distributor which sets the base ignition timing. The factory timing is 10* btdc on piston #1(rear head, passenger most side). For whatever reason... Many cars that came from the factory have slightly retarded timing, in the 7-8*btdc range.
Instuctions
The distributor is located under the intake manifold. it is held to the rear cylinder head by two 12mm bolts. Loosen them a few turns - enough to hold the distributor on, but loose enough to turn it!
The 1992-1993 3vz-fe is highly resistant to detonation because of very weak factory tuning. With a timing light and the ECU in diagnostic mode (jumper E1 and TE1 in either Diagnostics port). Set the timing to 17*btdc. There should be no reason to run higher grade gas. Continue to run 87 octane.
1987-1991 2vz-fe should start at 15*btdc. There should be no reason to run higher grade gas. Continue to run 87 octane.
There may be a 3hp - possibly 5hp peak gained, much better throttle response, and a very small mpg boost from adding ignition timing.
*****************************************
Part I Quicker Transmission Shifting
Part III Tuning the ECU
Part IV Cooling
Part V How to pick up MPG, and sleep with her too!
Part VI Acing Aerodynamics
Part VII Cheap Water Injection
Part VIII Cheaply Monitoring the ECU & A/F Ratios
*****************************************
Last edited by Pheonix; 07-03-05 at 07:11 AM.
02-28-06, 12:31 PM
#3
Lexus Champion
Thread Starter
That is a very good question. Due to being asked very similar questions way too many times, I postponed doing my next valve body modification (this week) to get data on that over the weekend.
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Pheonix
ES - 1st to 4th Gen (1990-2006)
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07-02-05 06:55 PM
