Converting a pre 89 Carb to EFI -Updated Full version 2/2016
Nov 11, 2010 3:00:35 GMT -4
lincolntbird likes this
Post by justyfied on Nov 11, 2010 3:00:35 GMT -4
I have done this to 2 different 1988 or older First generation Justies now. I have removed and replaced the carburetor fuel system with an EFI system from a second gen Justy.
I wanted to have the benefits of the reliable, efficient and more powerful EFI system installed in the lighter 1st gen chassis.
I do not have the money to afford an aftermarket system, So this is the VERY labour intensive but affordable route that I took.
The following is a mish mash of pictures from both of my conversion projects, a Red and a Silver 88 Justy.
For those that have the pleasure of owning a Subaru with Electronic Fuel Injection, They already know how much it is better than a Carburetor.
This post is meant to convince those with a little mechanical savy to go ahead and convert your carburetor subie into an EFI subie using Genuine
subaru parts. The result will be a reliable, all weather starting, smooth running, fun to drive machine.
First off I would like to cover some of the differences from the first version of the Justy and the post 88 version which has some changes to the body style.
The nose of the car was moved ahead approximately 4 inchs--(100MM) To give room for a wider larger capacity radiator. This was accomplished by moving the rad. support ahead and lengthening the front fenders and hood.
That is why I removed about 50 mm or 2 inch's from the rectangular intake tube over the engine, otherwise it will not fit. I cut it apart and glued in back together with shoe goop.
Another difference that is important here is that the wiring harness grommet flanges in the fire wall are a different size. This makes it difficult to retro fit an EFI wiring harness into a carb. vehicle.
Pictures of that below.
Third, the carb fuel tank draws the fuel from the side of the tank, unlike the efi system. The efi fuel pump is mounted INSIDE the tank. The efi fuel tank, while looking the same externally is noticeably heavier because of all the extra baffling that is necessary on the inside. And just to complicate matters, the fuel sender/fuel pump assembly has a bigger mounting flange. This means that an efi sender/pump cannot be fit into a carb tank. The fuel supply line is just a little larger on the efi also. Plus the wire connectors to the Sender/pump unit are different.
Fourth major difference is that the cylinder heads are different. Either one one will fit on the engine and the valve covers are the same. But the coolant passages around the intake ports make it so that the intake manifolds will not swap over, the head has to match the intake.
The exhaust manifolds are different in the angle of the Catalytic converter,but they are interchangeable. The carb version of exhaust manifold has an exhaust recirculation pipe that goes from the outlet of the cat. to the bottom of the intake on the other side of the engine.
The carb. Version has a traditional round air cleaner housing mounted above the carb with the cold air intake over near the battery. The efi has plastic air piping from the throttle-body, over the valve cover, and then the exhaust manifold to the square air cleaner housing on the opposite fender.
The list of parts required to do the conversion is long, so if possible it is best to obtain a donor car to take all the parts from. Rather than buying them individually from an Auto dismantler/recycler.To do this conversion with all the Justy parts you will need:
EFI Fuel tank
Alternator
Distributor and Ignitor (COIL)
Fuel supply, return and vent lines from the tank to the engine (triple lines in 1 piece)
Throttle cable and accelerator peddle
Cylinder head and intake manifold complete with throttle-body and all relevant fittings and connections
All air inlet tubing including the flat aircleaner box
The complete entire wiring harness
Complete dash pod and instrument cluster
The steering column
4 wd drive vacuum switcher unit
Instrument cluster and cover/ Pod unit.. ... Correct 4 wd STANDARD unit or if you use a ECVT unit the Tach will not work.
First thing I did after removing the Fuel tank, seats and carpet was to cut out the fuel pump or fuel tank access hole found under the back seat. On the Carb car the cover and hole is smaller. So with a jig saw I cut it out to fit the EFI one from a newer car. Of course this is easier done after the tank is removed -- since it has to be changed anyway!
The fuel tank flange corners have to be pried out from under the trailing link pickups that are probably put on after the tank is installed
Then the side plastic panels and the dash, and steering column are removed, It is easy enough to remove the whole thing. take out the 1 bolt on the bottom u joint and the 1 bolt up top and pull it out, since it has to be switched over anyway.
Also make sure to remove the wires from the back of the ignition switch before unbolting the bolt that supports the steering column or the switch's bakealite back will get broken. Don't ask me how I know these things.
Warning: Remove the hoses from the heater core on the engine side of the firewall before removing the dash or you will damage the heater core which is removed from the inside.
With the dash out it is possible to switch over the fuel lines which are ever so slightly bigger on the supply line for the EFI.
Both carb and efi have 3 lines: 1 supply, 1 return , and 1 vapor line.
Best to remove the short fuel lines from the engine side of the lines before removing the triangular bulk head fitting with the lines through the fire wall.
The next thing is to start adapting the 2 oval shaped holes on either side of the fire wall for the wiring harness from the engine side. I cut out this area with a long jigsaw blade from my post 88 scraped donor car.
After opening the holes up I put down a layer of silicone on the car before pop riveting the new bigger holes from the donor car in place. Then apply a touch more silicone to seal it all up.
The right side now, Take care you do not cut the fuel lines inside.
Then you can start putting the dash in when all the wiring is pulled through and hooked up.
Also If you switch all the wiring as a unit through the firewall on the drivers side, it also has the hood release cable with it. The hood release bracket on the door post where the t handle is- is extremely difficult to remove. The 2 bolts are put in with liquid lock tight from the factory and I have tried to remove them so many times to no avail. I end up just taking a chisel to the bolt heads.
Anyway, unhook the hood release cable from the rad support and pull it out of the old harness and pull it through the new wires after installed to make it work.
The release mech on the different models are different.
The Dash and Steering column are a direct no hassle swap, they bolt right in. The reason I swap them is that the wiring harness from the second gen including the harness that goes from left to right inside the dash was switched. Then with the slightly different connectors on the column (Mostly ignition switch) and the dash to various box's and controls are all compatible.
If you want to spend some extra time and follow each circuit in the dash harness, you might be able to swap the dash harness into the older dash after cutting and connecting the different connectors for the switch's which will be in different spots.
The great thing is that there are only TWO dash pads, left and right hand drive vehicles, Period! from 84 to 95 they are all the same. The difference is the instrument pod changed when the body was upgraded in 89. The first gen dash can be converted to a second gen by swapping the instrument pod and cover plus the 2 metal mounts to the dash. This means that the vehicle identification number on the dash can stay with the car it came with.
The only quick connectors from the old wiring that I cut off and switched onto the new harness are for the front corner marker lights, headlights front signal lights and the interior dome light. Even the connectors for the gas tank are different, so I basically removed all the seats and the carpet to switch it all over. Check my post below about which connectors have to be cut off and soldered on.
You do not have to change the transmission as they are the same, even the engine short block(Engine without the cylinder head ) is the same. You can swap over the wires that are on the transmission.
So if you want to just remove and replace the cylinder head only that will work too.
However I feel it is just as easy to swap an entire complete engine as it is to r and r a head in the car. Just my impression on that.
They all will swap any where because the cars are the same from the firewall back, just the outside sheet metal is different from the the firewall forward, the roof, and rear hatch deck lid.
So .. .. you can get a dash from any 89 and up car carbed or efi. Just bolt in your EFI dash harness and MOST important. Make sure that you have the correct speedo cluster swapped in. The little map of the car inside the speedo is different from ECVT to Std cars.
These clips are different and you will need to swap them when changing the pods onto the dash.
Another thing you should change is both the throttle peddle assembly and the throttle cable up to the intake. The EFI 2nd gen throttle pedal bolts right in and looks to be the same but it actually has a bigger travel. The carb cable is shorter and being a little kinked will wear out as it is binding. This is what a carb cable looks like on an EFI intake:
Because the first gen is shorter up front it is a little tuff to mount this but it does fit.
1st off , While I can still remember---I want to mention all of the plugs and or wires that I cut off and soldered onto the Second Gen Harness I swapped into my 1st gen car.
All of the items mentioned below were cut off of the first gen. harness and soldered onto the second gen harness:
Headlight connectors
Front marker lights with bulbs
Front signal lights with bulbs
Alternator plug if you do not want to upgrade to a bigger 2nd gen alternator
Cut off the plugs that go to the rear window and windshield wiper in the back hatch, to make an adapter plug to the new harness.
Below are the things I cut off of the second gen wiring harness and solder onto wires that I did not change.
2 bullet plugs on the right side door pillar that goes to the dome light in the roof.
2 connectors that go from the rear defroster and windshield wiper on the hatch of the DONOR 2nd gen car, these are soldered to the other connectors from the 1st gen harness to make a double female connector adapter, the wires on the rear hatch are a bugger to change through the right rear pillar of the car.
I wanted to have the benefits of the reliable, efficient and more powerful EFI system installed in the lighter 1st gen chassis.
I do not have the money to afford an aftermarket system, So this is the VERY labour intensive but affordable route that I took.
The following is a mish mash of pictures from both of my conversion projects, a Red and a Silver 88 Justy.
For those that have the pleasure of owning a Subaru with Electronic Fuel Injection, They already know how much it is better than a Carburetor.
This post is meant to convince those with a little mechanical savy to go ahead and convert your carburetor subie into an EFI subie using Genuine
subaru parts. The result will be a reliable, all weather starting, smooth running, fun to drive machine.
First off I would like to cover some of the differences from the first version of the Justy and the post 88 version which has some changes to the body style.
The nose of the car was moved ahead approximately 4 inchs--(100MM) To give room for a wider larger capacity radiator. This was accomplished by moving the rad. support ahead and lengthening the front fenders and hood.
That is why I removed about 50 mm or 2 inch's from the rectangular intake tube over the engine, otherwise it will not fit. I cut it apart and glued in back together with shoe goop.
Another difference that is important here is that the wiring harness grommet flanges in the fire wall are a different size. This makes it difficult to retro fit an EFI wiring harness into a carb. vehicle.
Pictures of that below.
Third, the carb fuel tank draws the fuel from the side of the tank, unlike the efi system. The efi fuel pump is mounted INSIDE the tank. The efi fuel tank, while looking the same externally is noticeably heavier because of all the extra baffling that is necessary on the inside. And just to complicate matters, the fuel sender/fuel pump assembly has a bigger mounting flange. This means that an efi sender/pump cannot be fit into a carb tank. The fuel supply line is just a little larger on the efi also. Plus the wire connectors to the Sender/pump unit are different.
Fourth major difference is that the cylinder heads are different. Either one one will fit on the engine and the valve covers are the same. But the coolant passages around the intake ports make it so that the intake manifolds will not swap over, the head has to match the intake.
The exhaust manifolds are different in the angle of the Catalytic converter,but they are interchangeable. The carb version of exhaust manifold has an exhaust recirculation pipe that goes from the outlet of the cat. to the bottom of the intake on the other side of the engine.
The carb. Version has a traditional round air cleaner housing mounted above the carb with the cold air intake over near the battery. The efi has plastic air piping from the throttle-body, over the valve cover, and then the exhaust manifold to the square air cleaner housing on the opposite fender.
The list of parts required to do the conversion is long, so if possible it is best to obtain a donor car to take all the parts from. Rather than buying them individually from an Auto dismantler/recycler.To do this conversion with all the Justy parts you will need:
EFI Fuel tank
Alternator
Distributor and Ignitor (COIL)
Fuel supply, return and vent lines from the tank to the engine (triple lines in 1 piece)
Throttle cable and accelerator peddle
Cylinder head and intake manifold complete with throttle-body and all relevant fittings and connections
All air inlet tubing including the flat aircleaner box
The complete entire wiring harness
Complete dash pod and instrument cluster
The steering column
4 wd drive vacuum switcher unit
Instrument cluster and cover/ Pod unit.. ... Correct 4 wd STANDARD unit or if you use a ECVT unit the Tach will not work.
First thing I did after removing the Fuel tank, seats and carpet was to cut out the fuel pump or fuel tank access hole found under the back seat. On the Carb car the cover and hole is smaller. So with a jig saw I cut it out to fit the EFI one from a newer car. Of course this is easier done after the tank is removed -- since it has to be changed anyway!
The fuel tank flange corners have to be pried out from under the trailing link pickups that are probably put on after the tank is installed
Then the side plastic panels and the dash, and steering column are removed, It is easy enough to remove the whole thing. take out the 1 bolt on the bottom u joint and the 1 bolt up top and pull it out, since it has to be switched over anyway.
Also make sure to remove the wires from the back of the ignition switch before unbolting the bolt that supports the steering column or the switch's bakealite back will get broken. Don't ask me how I know these things.
Warning: Remove the hoses from the heater core on the engine side of the firewall before removing the dash or you will damage the heater core which is removed from the inside.
With the dash out it is possible to switch over the fuel lines which are ever so slightly bigger on the supply line for the EFI.
Both carb and efi have 3 lines: 1 supply, 1 return , and 1 vapor line.
Best to remove the short fuel lines from the engine side of the lines before removing the triangular bulk head fitting with the lines through the fire wall.
The next thing is to start adapting the 2 oval shaped holes on either side of the fire wall for the wiring harness from the engine side. I cut out this area with a long jigsaw blade from my post 88 scraped donor car.
After opening the holes up I put down a layer of silicone on the car before pop riveting the new bigger holes from the donor car in place. Then apply a touch more silicone to seal it all up.
The right side now, Take care you do not cut the fuel lines inside.
Then you can start putting the dash in when all the wiring is pulled through and hooked up.
Also If you switch all the wiring as a unit through the firewall on the drivers side, it also has the hood release cable with it. The hood release bracket on the door post where the t handle is- is extremely difficult to remove. The 2 bolts are put in with liquid lock tight from the factory and I have tried to remove them so many times to no avail. I end up just taking a chisel to the bolt heads.
Anyway, unhook the hood release cable from the rad support and pull it out of the old harness and pull it through the new wires after installed to make it work.
The release mech on the different models are different.
The Dash and Steering column are a direct no hassle swap, they bolt right in. The reason I swap them is that the wiring harness from the second gen including the harness that goes from left to right inside the dash was switched. Then with the slightly different connectors on the column (Mostly ignition switch) and the dash to various box's and controls are all compatible.
If you want to spend some extra time and follow each circuit in the dash harness, you might be able to swap the dash harness into the older dash after cutting and connecting the different connectors for the switch's which will be in different spots.
The great thing is that there are only TWO dash pads, left and right hand drive vehicles, Period! from 84 to 95 they are all the same. The difference is the instrument pod changed when the body was upgraded in 89. The first gen dash can be converted to a second gen by swapping the instrument pod and cover plus the 2 metal mounts to the dash. This means that the vehicle identification number on the dash can stay with the car it came with.
The only quick connectors from the old wiring that I cut off and switched onto the new harness are for the front corner marker lights, headlights front signal lights and the interior dome light. Even the connectors for the gas tank are different, so I basically removed all the seats and the carpet to switch it all over. Check my post below about which connectors have to be cut off and soldered on.
You do not have to change the transmission as they are the same, even the engine short block(Engine without the cylinder head ) is the same. You can swap over the wires that are on the transmission.
So if you want to just remove and replace the cylinder head only that will work too.
However I feel it is just as easy to swap an entire complete engine as it is to r and r a head in the car. Just my impression on that.
They all will swap any where because the cars are the same from the firewall back, just the outside sheet metal is different from the the firewall forward, the roof, and rear hatch deck lid.
So .. .. you can get a dash from any 89 and up car carbed or efi. Just bolt in your EFI dash harness and MOST important. Make sure that you have the correct speedo cluster swapped in. The little map of the car inside the speedo is different from ECVT to Std cars.
These clips are different and you will need to swap them when changing the pods onto the dash.
Another thing you should change is both the throttle peddle assembly and the throttle cable up to the intake. The EFI 2nd gen throttle pedal bolts right in and looks to be the same but it actually has a bigger travel. The carb cable is shorter and being a little kinked will wear out as it is binding. This is what a carb cable looks like on an EFI intake:
Because the first gen is shorter up front it is a little tuff to mount this but it does fit.
1st off , While I can still remember---I want to mention all of the plugs and or wires that I cut off and soldered onto the Second Gen Harness I swapped into my 1st gen car.
All of the items mentioned below were cut off of the first gen. harness and soldered onto the second gen harness:
Headlight connectors
Front marker lights with bulbs
Front signal lights with bulbs
Alternator plug if you do not want to upgrade to a bigger 2nd gen alternator
Cut off the plugs that go to the rear window and windshield wiper in the back hatch, to make an adapter plug to the new harness.
Below are the things I cut off of the second gen wiring harness and solder onto wires that I did not change.
2 bullet plugs on the right side door pillar that goes to the dome light in the roof.
2 connectors that go from the rear defroster and windshield wiper on the hatch of the DONOR 2nd gen car, these are soldered to the other connectors from the 1st gen harness to make a double female connector adapter, the wires on the rear hatch are a bugger to change through the right rear pillar of the car.