The supercharger is old news, as is the lean issue with the ‘93-94s. But, the only solution to the supercharged lean condition I found searching a lot of posts was water/methanol injection (but maybe I missed a post… or two). I didn’t want to go this route and decided to add a 7th injector. This is a quick summary of what I did.
Installation:
I made and installed a riser nipple to get access to fuel from the fuel rail. This allows me to install AN fittings and hose that provide fuel to the 7th injector.
I butchered a spare throttle body and used it mount the injector. I cut off everything and filled all vacuum ports with JB weld. I then drilled and reamed a hole for the injector and made a small fuel rail to accept the AN hose at the injector. The completed and installed system is pictured below.
The hacked throttle body is my prototype and used for my initial installation and testing/setup. However, I am currently making a sandwich plate and will use this for my final install. This will replace the hacked up throttle body and will use the original TRD supplied intake runner for a clean (somewhat professional) look.
I used an injector from a ’95 that a local mud member was parting out. I picked up the whole set of injectors and the electrical connection plug with pig-tails (Thanks Pat).
Enricher
Before I can start adding additional fuel, I need to modify the signal from the O2 sensors. This is needed because the ECU is good at keeping things at 14.7 AFR. So, when in closed-loop, no matter how much fuel is added with my 7th injector, the ECU is trimming back the primary injectors to obtain 14.7 AFR. Without the Enricher, I can’t get my target AFR of 11.8-12.0 under boost in closed-loop, which is essential.
I used the Split Second Enricher. Installation is simple and requires cutting the O2 sensor wire (blue/white=OX1and white=OX2 on the ‘94) on each of the two sensors. Wires are connected to the signal wire from the O2 sensor and routed to the Enricher and then back to the wire that goes to the ECU. A hose on the Enricher is connected to the manifold to measure boost pressure.
A very clean OEM looking installation could be made without cutting any oem wires using an extra set of OEM O2 sensor connection plugs. But, you would need both the harness plug and the sensor plug. The sensor plug is easy to get from a set of old dead O2 sensors, but I was not able to find anyone willing to part out the harness plugs. The vehicle I sourced for parts was a ’95 which uses a different shaped plug than my ’94.
Injector Controller
The additional injector controller is the Split Second AIC1 which can control up to two injectors. Installation is also very simple. I took the tach signal and power from the igniter which is located near the ABS module (tach=IGF black/green, power=black/green as well?, but small 24AWG wire is tach and large 14AWG is power on the ’94). There is also a hose from the controller to the manifold to measure boost pressure. Using the pigtail I got with the injector I was able to easily connect the controller to the injector.
Programming
The Enricher is all hardware settings. I set mine to activate at 0-psig (i.e., 14.7 psi absolute) which is also the same pressure that I start adding additional fuel with the 7th injector. The amount of enrichment is controlled via adjustable pots representing the percentage of enrichment. I am currently set at 60%.
The injector controller is software programmed. The provided software is very basic and kinda sucks, but gets the job done. A laptop with Win-XP is required. The engine programming is set to 3-cylinder, 2-stroke to fire the injector at each ignition pulse. A fuel map is created by assigning a time in milliseconds (msec) for each rpm valve (increments of 500 rpm) and corresponding manifold pressure value in 0.5-psi increments. The time represents the ‘on’ time of the injector for each ignition pulse. A setting of at least 1-msec is required fire the injector and therefore, settings are in multiples of 1 millisecond.
The software provides real time data, which is how I created my fuel map. This is where a dyno would be a big time saver, but I’m too cheap to buy dyno time and just watched the live data while driving and modified the map as necessary to get my desired AFR.
Misc.
I assume anyone running the blower already has an exhaust gas temp gauge (EGT) and an air-fuel-ratio (AFR) meter. I quickly found that although there is no exact consensus on the correct AFR, 11.8-12.0 keeps the EGT in check without the worry of melting things. Also, the hardest part to tune is the low-medium boost while in closed-loop. This is the long easy grade that generates moderate boost for long periods of time and will kill your engine if you don’t have the correct AFR.
I also found that there is no problem with providing enough fuel, contrary to several post that state larger injectors or a bigger fuel pump is needed. The 7th injector is able to provide plenty of fuel using the stock fuel pump and stock injectors.
The Enricher is $199 and the injector controller is $289, so the cost is about equivalent to doing water injection and provides the ability to fully control the AFR over the entire boost range.
I have been doing a lot of driving around home, done a few local trips and just did a +900 mile Death Valley trip and could not be happier with the setup. At a time when there are lots of posts about engine swaps and turbos, I think the bolt-on SC is the best bang-for-your-buck option for more power. And, a 7th injector is an option on the’93-94 to cure the lean condition.
Installation:
I made and installed a riser nipple to get access to fuel from the fuel rail. This allows me to install AN fittings and hose that provide fuel to the 7th injector.
I butchered a spare throttle body and used it mount the injector. I cut off everything and filled all vacuum ports with JB weld. I then drilled and reamed a hole for the injector and made a small fuel rail to accept the AN hose at the injector. The completed and installed system is pictured below.
The hacked throttle body is my prototype and used for my initial installation and testing/setup. However, I am currently making a sandwich plate and will use this for my final install. This will replace the hacked up throttle body and will use the original TRD supplied intake runner for a clean (somewhat professional) look.
I used an injector from a ’95 that a local mud member was parting out. I picked up the whole set of injectors and the electrical connection plug with pig-tails (Thanks Pat).
Enricher
Before I can start adding additional fuel, I need to modify the signal from the O2 sensors. This is needed because the ECU is good at keeping things at 14.7 AFR. So, when in closed-loop, no matter how much fuel is added with my 7th injector, the ECU is trimming back the primary injectors to obtain 14.7 AFR. Without the Enricher, I can’t get my target AFR of 11.8-12.0 under boost in closed-loop, which is essential.
I used the Split Second Enricher. Installation is simple and requires cutting the O2 sensor wire (blue/white=OX1and white=OX2 on the ‘94) on each of the two sensors. Wires are connected to the signal wire from the O2 sensor and routed to the Enricher and then back to the wire that goes to the ECU. A hose on the Enricher is connected to the manifold to measure boost pressure.
A very clean OEM looking installation could be made without cutting any oem wires using an extra set of OEM O2 sensor connection plugs. But, you would need both the harness plug and the sensor plug. The sensor plug is easy to get from a set of old dead O2 sensors, but I was not able to find anyone willing to part out the harness plugs. The vehicle I sourced for parts was a ’95 which uses a different shaped plug than my ’94.
Injector Controller
The additional injector controller is the Split Second AIC1 which can control up to two injectors. Installation is also very simple. I took the tach signal and power from the igniter which is located near the ABS module (tach=IGF black/green, power=black/green as well?, but small 24AWG wire is tach and large 14AWG is power on the ’94). There is also a hose from the controller to the manifold to measure boost pressure. Using the pigtail I got with the injector I was able to easily connect the controller to the injector.
Programming
The Enricher is all hardware settings. I set mine to activate at 0-psig (i.e., 14.7 psi absolute) which is also the same pressure that I start adding additional fuel with the 7th injector. The amount of enrichment is controlled via adjustable pots representing the percentage of enrichment. I am currently set at 60%.
The injector controller is software programmed. The provided software is very basic and kinda sucks, but gets the job done. A laptop with Win-XP is required. The engine programming is set to 3-cylinder, 2-stroke to fire the injector at each ignition pulse. A fuel map is created by assigning a time in milliseconds (msec) for each rpm valve (increments of 500 rpm) and corresponding manifold pressure value in 0.5-psi increments. The time represents the ‘on’ time of the injector for each ignition pulse. A setting of at least 1-msec is required fire the injector and therefore, settings are in multiples of 1 millisecond.
The software provides real time data, which is how I created my fuel map. This is where a dyno would be a big time saver, but I’m too cheap to buy dyno time and just watched the live data while driving and modified the map as necessary to get my desired AFR.
Misc.
I assume anyone running the blower already has an exhaust gas temp gauge (EGT) and an air-fuel-ratio (AFR) meter. I quickly found that although there is no exact consensus on the correct AFR, 11.8-12.0 keeps the EGT in check without the worry of melting things. Also, the hardest part to tune is the low-medium boost while in closed-loop. This is the long easy grade that generates moderate boost for long periods of time and will kill your engine if you don’t have the correct AFR.
I also found that there is no problem with providing enough fuel, contrary to several post that state larger injectors or a bigger fuel pump is needed. The 7th injector is able to provide plenty of fuel using the stock fuel pump and stock injectors.
The Enricher is $199 and the injector controller is $289, so the cost is about equivalent to doing water injection and provides the ability to fully control the AFR over the entire boost range.
I have been doing a lot of driving around home, done a few local trips and just did a +900 mile Death Valley trip and could not be happier with the setup. At a time when there are lots of posts about engine swaps and turbos, I think the bolt-on SC is the best bang-for-your-buck option for more power. And, a 7th injector is an option on the’93-94 to cure the lean condition.
