CFI to MPFI Tutorial Version 1.0
Posted: July 15th, 2007, 10:48 pmCFI to MPFI Tutorial
In this, we will guide you through steps to take to turn your car from CFI (Center Fuel Injection) to MPFI (Multipoint Fuel Injection).
CFI was used on Series 1 EA's to Series 1 EB's, not all were CFI, as MPFI was an optinal for S-Pacs Fairmonts and Fairlanes , Series 2 EBs and onwards would only have MPFI.
What is the Difference between CFI and MPFI?
Center Fuel Injectionwas a Delivered threw and Intake Manifold Carby where it would be distributed threw all 6 Cylinders, this method was a very Ecconomical way of delivery fuel to the Piston Cylinders.
Multipoint Fuel Injection was a more reliable way of delivery fuel to the Pistion Cylinders, Injectors were attatched to the top of the manifold for each Cylinder, Fuel would be Sprayed in a Sequence into the Cylinder.
What Parts are needed?
MPFI Intake Manifold
Fuel Rail
6 x Injectors
MPFI Fuel Pump*
TPS
ISC
Air Temprature Sensors.
MPFI A/C Compressor Bracket*
Gasket sealant. Commonly Gasket Goo
Intake Manifold Gasket.
You could get an MPFI dizzy, but I have never had an issue with it in all the conversions I've done. Just use the CFI dizzy.
*A/C compressor bracket off MPFI (EA/ED only) as the compressor must be moved down to clear the manifold. Make sure to get the two bolts, which hold it onto the block!
A spare pin to go in the computer loom (female) side of the manifold plug (I will refer to this plug assembly from now on as the 'main' plug). Plus about a metre of wire, salvaged from the same loom, as the pin is easiest.
*A MPFI fuel pump - get the right pump for the manifold as the fuel rail pressures vary between models.
MPFI brake booster hose (EA-ED), EA/ED breather hose (back of rockercover to throttle body), and an appropriate MAP sensor hose.
you wil also needed is a length of 5/8 heater hose, 1m is sufficient, measuring anyway is recommended, and if you want the metal pipes. One runs round the back of the motor and the other comes out of the thermostat housing. The back pipe is not really necessary, but the front one will require bending to fit around the new manifold.
The MPFI manifold loom. Now be careful with this, there are several differences between models. Most Falcons have a little pink wire which connects to the dizzy at the front of the manifold. If you have it, MAKE SURE THE NEW LOOM DOES! If you don't have it, I don't remember that it matters overmuch. Sometimes the pins inside the main loom plug are arranged in a different order. This is not very common and I don't know why, however I have seen it twice before. The other major difference is in the shape of the TPS and ISC plugs.
On the ED, EF, and EL, the plugs are a different shape to the earlier models. If you are fitting an EF or EL manifold, you will require an ED loom. You will also need to swap the EF/EL ISC plug onto your ED loom.
What Tools will you need?
• Hammer!
• Socket set, universal joint and lots of extensions.
• Paint pen, permo or something.
• Medium Phillips and flathead screwdrivers.
• Set of Allen(hex) keys.
• Big screwdriver or other lever.
• Vice grips.
• Knife/straight razor.
• Wire cutters/scissors, or, use the knife.
• Soldering iron, solder, and Electrical Tape.
• Voltmeter/Continuity tester, if you have one.
• Paperclip, jeweller's screwdriver, pin, something to operate the little plastic clips which hold the pins into the main loom plug.
This is the Paitent, a 91 EB GLi. Now, Before you start, this is important!
NOTE: The first thing you'll want to do is check the dizzy won't foul on the new manifold.
If it does, it's going to get complicated. I'll put that explanation at the end as it'll be quite long and will break the flow. Refer there now if you have this problem
You need to undo the two fuel lines from the carby. Mark which is which. If you lose them the fuel filter is on the inlet hose.
Unplug the spark plug leads from the plugs, be sure to mark them.
Undo the main plug and the square 4-pin plug next to it. Undo the coil, suppressor, oil sensor, and where fitted, the little pink wire at the front. Also undo the gearbox plug (4-speed only) from the secondary TPS sensor, and the ISC plug.
Undo the brake booster hose, vacuum supply hoses, and MAP sensor hose.
Undo the accelerator cable, and kickdown (3-speed only)
Unbolt the flange holding the metal pipe into the thermostat housing, and the flange holding the Y-shaped piece of pipe into the back of the manifold. These pipes are easiest to remove later on.
Unbolt the support for the dipstick, then pull out the whole dipstick tube.
Undo the purge canister hose (orange, underneath the manifold), the breather hose off the back of the rockerbox, and the PCV hose.
Undo the bolts holding the manifold on, completely removing all except one top one at each end. Then, supporting the manifold, remove the top bolts.
Now that the manifold is free, it will be easier to pull the metal pipes out, which are likely to prove very stiff. Vice grips and a big screwdriver (lever) seem to work the best. Twisting helps too.
Preparing the engine bay
First things first, let's look at the wiring. If you're lucky, you have a manual or 3-speed and your job is easy. If you have a 4-speed it's a bit harder.
The first bit of wiring, common to both, is to cut the grey/white wire about an inch away from the idle motor plug. Extend it up to the computer loom part of the main loom plug, cut to length and add the pin on the end. Then put it into the plug so that it corresponds with the grey/white wire on the MPFI loom. While you're messing about in the plug, make sure all the other wires correspond correctly.
Then, ONLY if you have a 4-speed, peel about 1/2 an inch of insulation - without cutting the wires! - off the three TPS wires in the manifold loom, a few inches before the main loom plug. These wires are green/black, black/white, and orange/black.
Cut the *gearbox* TPS plug off the old CFI manifold loom, leaving as much wire on the plug as possible. Now wire it up to the stripped wires. It should have a black, a green, and an orange wire. These correspond to the TPS wire colours.
You will also want to disconnect the heater hose from the metal pipe round the back of the motor, as it'll have to go between the new manifold's runners (only if it's an EA-ED one).
Unbolt the a/c compressor and install the bracket for it, then bolt it back on in the new, low position (again, EA/ED only).
These are the old brackets you need to change these.
Carefully scrape the remains of the old gasket away with the razor blade.
If you're making your own gasket, fold the cornflakes packet open and place it over the CFI manifold where the gasket should go. Make holes for the bolts and slide them into the holes so that they hold the gasket down.
Next, use the hammer to gently but firmly tap around the outside of the manifold so as to cut the cardboard to shape. Use the knife for tricky spots. Then use the knife to do the inside. Once you have your gasket, position it on the MPFI manifold and cut out the bits where the injectors go.
It's not a bad idea to clean the bay up while it's empty....
Installing the new manifold
First, make sure it's fully assembled, except for the fuel rail/injectors. If it's an EF/EL manifold, take the throttle body off, being careful not to damage the gasket.
Lower the manifold into the bay.
Feed the heater hose through between 5 and 6 runners (EA only; EF the hose just goes under the manifold) and reconnect it to the metal pipe. I generally find that it I don't use sealant, these hoses will leak no matter how tight they are.
It will also be a really good idea to connect the coil, suppressor, and oil sender at this time - they will be VERY DIFFICULT later if it's an EA manifold.
Feed the plug leads through the manifold between 2 and 3 runners. Leave them loose for the minute.
Plug in the little pink wire and feed the fuel lines up between the manifold and bulkhead so you won't have to search for them later.
Smear some sealant on the end of the metal hose from the thermostat and push it back in. Just secure the bolt loosely for the minute.
Now put the length of 5/8 hose on the Y-shaped bit you disconnected from the CFI manifold. Again, use sealant. Run the pipe around the outside of the manifold to the thermostat metal pipe, and make the metal pipe fit around the manifold Be careful not to bend it too far at one time, or you'll kink the metal.
Now secure the manifold loosely with a bolt through the top at each end. Put the gasket in now. Make sure all the plugs are connected and the fuel lines up, then put the rest of the bolts in loosely before you tighten ANY. This is because the gasket can slide down so that some bolts won't go in. If this happens and you tighten it up, you'll be undoing a lot of bolts to fix it - and swearing a lot too.
Now connect the main plug and the little 4-pin square plug next to it. Also the gearbox plug if you have it. Do the pink wire too so we don't forget it.
Connect the new brake booster hose, the vacuum supply hoses, the breather hose, and the new MAP sensor hose. *WARNING* Only do this now if it's an EA manifold, if it's EF then wait until the fuel rail's in!
Then do the purge canister and PCV hoses.
Next do the fuel rail. Lubricate the O-rings on the injectors with a little clean engine oil before installation. Make sure to fit and tighten the fuel lines before bolting the rail down. On both MPFI manifolds, the dipstick is secured to a fuel rail bolt. If you're using the CFI dipstick, bend it carefully to fit.
You may notice that your new loom has a little grey or grey/blue wire with a brass loop on the end. This is an earth wire, earth it by putting one of the fuel rail bolts through it. Or manifold bolts, depending on where it stretches to.
In the case of the EF manifold, this is when you install the throttle body and vacuum hoses.
Now hook up the accelerator cable and kickdown if you have it. Double-check the throttle is opening fully.
Top up the water.
Starting the car
Switch the key on, but do not engage the starter. Wait for the fuel pump to finish priming. Do this a few times to remove air from the line. After that, it should start fine. Double-check for vacuum and water leaks.
Take it for a drive to get it warm, then check for water leaks again. In the case of the 4-speed, if it won't kick down you most likely wired up the gearbox TPS switch wrong.
Moving Distrubutor PLugs Around
OK if you had troubles with your dizzy position here's what you do.
Going off the plug leads on top of the dizzy, mark one of the leads. Now determine how many leads you have to move it so that it's out of the way, and one of the leads is exactly where the marked one was.
Now being careful not to lose the order, change the position of the marked lead on the dizzy cap until the marked lead is on the post now occupying it's old position. Move the other leads accordingly. This should render the timing similar to what it was. Try to run the engine.
If it runs, but badly, loosen the retaining clip and slowly twist it until the engine runs at its fastest speed. Keep it at idle.
If you had to move the leads, and now the car won't start, you are going to have to do a 'static time'.
The diistrubutor spins clockwise. The firing order is 1-5-3-6-2-4.
Find lead 1 and note where it is relative to the distributor body. Now take the rotor cap off and crank the motor until the timing notch meets the '0' indicator on the timing cover. This is TDC or Top Dead Centre. If you can't spin it with the belts, the bolt in the balancer is a 22mm socket.
Since the motor reaches TDC twice in a single cycle, you are looking at TDC at either the end of the compression stroke, when it should fire, or the end of the exhaust stroke, when it should not fire.
OK now if the rotor button is close to your number 1 lead, twist the dizzy to meet it. If not, rotate the motor until it hits TDC again. Is it any closer? If so, twist the dizzy to meet it.
Then put the cap back on and try to start it again. If it starts, twist the dizzy until it runs properly.
Now you can keep up with the N/A boys! Up the back.
In this, we will guide you through steps to take to turn your car from CFI (Center Fuel Injection) to MPFI (Multipoint Fuel Injection).
CFI was used on Series 1 EA's to Series 1 EB's, not all were CFI, as MPFI was an optinal for S-Pacs Fairmonts and Fairlanes , Series 2 EBs and onwards would only have MPFI.
What is the Difference between CFI and MPFI?
Center Fuel Injectionwas a Delivered threw and Intake Manifold Carby where it would be distributed threw all 6 Cylinders, this method was a very Ecconomical way of delivery fuel to the Piston Cylinders.
Multipoint Fuel Injection was a more reliable way of delivery fuel to the Pistion Cylinders, Injectors were attatched to the top of the manifold for each Cylinder, Fuel would be Sprayed in a Sequence into the Cylinder.
What Parts are needed?
MPFI Intake Manifold
Fuel Rail
6 x Injectors
MPFI Fuel Pump*
TPS
ISC
Air Temprature Sensors.
MPFI A/C Compressor Bracket*
Gasket sealant. Commonly Gasket Goo
Intake Manifold Gasket.
You could get an MPFI dizzy, but I have never had an issue with it in all the conversions I've done. Just use the CFI dizzy.
*A/C compressor bracket off MPFI (EA/ED only) as the compressor must be moved down to clear the manifold. Make sure to get the two bolts, which hold it onto the block!
A spare pin to go in the computer loom (female) side of the manifold plug (I will refer to this plug assembly from now on as the 'main' plug). Plus about a metre of wire, salvaged from the same loom, as the pin is easiest.
*A MPFI fuel pump - get the right pump for the manifold as the fuel rail pressures vary between models.
MPFI brake booster hose (EA-ED), EA/ED breather hose (back of rockercover to throttle body), and an appropriate MAP sensor hose.
you wil also needed is a length of 5/8 heater hose, 1m is sufficient, measuring anyway is recommended, and if you want the metal pipes. One runs round the back of the motor and the other comes out of the thermostat housing. The back pipe is not really necessary, but the front one will require bending to fit around the new manifold.
The MPFI manifold loom. Now be careful with this, there are several differences between models. Most Falcons have a little pink wire which connects to the dizzy at the front of the manifold. If you have it, MAKE SURE THE NEW LOOM DOES! If you don't have it, I don't remember that it matters overmuch. Sometimes the pins inside the main loom plug are arranged in a different order. This is not very common and I don't know why, however I have seen it twice before. The other major difference is in the shape of the TPS and ISC plugs.
On the ED, EF, and EL, the plugs are a different shape to the earlier models. If you are fitting an EF or EL manifold, you will require an ED loom. You will also need to swap the EF/EL ISC plug onto your ED loom.
What Tools will you need?
• Hammer!
• Socket set, universal joint and lots of extensions.
• Paint pen, permo or something.
• Medium Phillips and flathead screwdrivers.
• Set of Allen(hex) keys.
• Big screwdriver or other lever.
• Vice grips.
• Knife/straight razor.
• Wire cutters/scissors, or, use the knife.
• Soldering iron, solder, and Electrical Tape.
• Voltmeter/Continuity tester, if you have one.
• Paperclip, jeweller's screwdriver, pin, something to operate the little plastic clips which hold the pins into the main loom plug.
This is the Paitent, a 91 EB GLi. Now, Before you start, this is important!
NOTE: The first thing you'll want to do is check the dizzy won't foul on the new manifold.
If it does, it's going to get complicated. I'll put that explanation at the end as it'll be quite long and will break the flow. Refer there now if you have this problem
You need to undo the two fuel lines from the carby. Mark which is which. If you lose them the fuel filter is on the inlet hose.
Unplug the spark plug leads from the plugs, be sure to mark them.
Undo the main plug and the square 4-pin plug next to it. Undo the coil, suppressor, oil sensor, and where fitted, the little pink wire at the front. Also undo the gearbox plug (4-speed only) from the secondary TPS sensor, and the ISC plug.
Undo the brake booster hose, vacuum supply hoses, and MAP sensor hose.
Undo the accelerator cable, and kickdown (3-speed only)
Unbolt the flange holding the metal pipe into the thermostat housing, and the flange holding the Y-shaped piece of pipe into the back of the manifold. These pipes are easiest to remove later on.
Unbolt the support for the dipstick, then pull out the whole dipstick tube.
Undo the purge canister hose (orange, underneath the manifold), the breather hose off the back of the rockerbox, and the PCV hose.
Undo the bolts holding the manifold on, completely removing all except one top one at each end. Then, supporting the manifold, remove the top bolts.
Now that the manifold is free, it will be easier to pull the metal pipes out, which are likely to prove very stiff. Vice grips and a big screwdriver (lever) seem to work the best. Twisting helps too.
Preparing the engine bay
First things first, let's look at the wiring. If you're lucky, you have a manual or 3-speed and your job is easy. If you have a 4-speed it's a bit harder.
The first bit of wiring, common to both, is to cut the grey/white wire about an inch away from the idle motor plug. Extend it up to the computer loom part of the main loom plug, cut to length and add the pin on the end. Then put it into the plug so that it corresponds with the grey/white wire on the MPFI loom. While you're messing about in the plug, make sure all the other wires correspond correctly.
Then, ONLY if you have a 4-speed, peel about 1/2 an inch of insulation - without cutting the wires! - off the three TPS wires in the manifold loom, a few inches before the main loom plug. These wires are green/black, black/white, and orange/black.
Cut the *gearbox* TPS plug off the old CFI manifold loom, leaving as much wire on the plug as possible. Now wire it up to the stripped wires. It should have a black, a green, and an orange wire. These correspond to the TPS wire colours.
You will also want to disconnect the heater hose from the metal pipe round the back of the motor, as it'll have to go between the new manifold's runners (only if it's an EA-ED one).
Unbolt the a/c compressor and install the bracket for it, then bolt it back on in the new, low position (again, EA/ED only).
These are the old brackets you need to change these.
Carefully scrape the remains of the old gasket away with the razor blade.
If you're making your own gasket, fold the cornflakes packet open and place it over the CFI manifold where the gasket should go. Make holes for the bolts and slide them into the holes so that they hold the gasket down.
Next, use the hammer to gently but firmly tap around the outside of the manifold so as to cut the cardboard to shape. Use the knife for tricky spots. Then use the knife to do the inside. Once you have your gasket, position it on the MPFI manifold and cut out the bits where the injectors go.
It's not a bad idea to clean the bay up while it's empty....
Installing the new manifold
First, make sure it's fully assembled, except for the fuel rail/injectors. If it's an EF/EL manifold, take the throttle body off, being careful not to damage the gasket.
Lower the manifold into the bay.
Feed the heater hose through between 5 and 6 runners (EA only; EF the hose just goes under the manifold) and reconnect it to the metal pipe. I generally find that it I don't use sealant, these hoses will leak no matter how tight they are.
It will also be a really good idea to connect the coil, suppressor, and oil sender at this time - they will be VERY DIFFICULT later if it's an EA manifold.
Feed the plug leads through the manifold between 2 and 3 runners. Leave them loose for the minute.
Plug in the little pink wire and feed the fuel lines up between the manifold and bulkhead so you won't have to search for them later.
Smear some sealant on the end of the metal hose from the thermostat and push it back in. Just secure the bolt loosely for the minute.
Now put the length of 5/8 hose on the Y-shaped bit you disconnected from the CFI manifold. Again, use sealant. Run the pipe around the outside of the manifold to the thermostat metal pipe, and make the metal pipe fit around the manifold Be careful not to bend it too far at one time, or you'll kink the metal.
Now secure the manifold loosely with a bolt through the top at each end. Put the gasket in now. Make sure all the plugs are connected and the fuel lines up, then put the rest of the bolts in loosely before you tighten ANY. This is because the gasket can slide down so that some bolts won't go in. If this happens and you tighten it up, you'll be undoing a lot of bolts to fix it - and swearing a lot too.
Now connect the main plug and the little 4-pin square plug next to it. Also the gearbox plug if you have it. Do the pink wire too so we don't forget it.
Connect the new brake booster hose, the vacuum supply hoses, the breather hose, and the new MAP sensor hose. *WARNING* Only do this now if it's an EA manifold, if it's EF then wait until the fuel rail's in!
Then do the purge canister and PCV hoses.
Next do the fuel rail. Lubricate the O-rings on the injectors with a little clean engine oil before installation. Make sure to fit and tighten the fuel lines before bolting the rail down. On both MPFI manifolds, the dipstick is secured to a fuel rail bolt. If you're using the CFI dipstick, bend it carefully to fit.
You may notice that your new loom has a little grey or grey/blue wire with a brass loop on the end. This is an earth wire, earth it by putting one of the fuel rail bolts through it. Or manifold bolts, depending on where it stretches to.
In the case of the EF manifold, this is when you install the throttle body and vacuum hoses.
Now hook up the accelerator cable and kickdown if you have it. Double-check the throttle is opening fully.
Top up the water.
Starting the car
Switch the key on, but do not engage the starter. Wait for the fuel pump to finish priming. Do this a few times to remove air from the line. After that, it should start fine. Double-check for vacuum and water leaks.
Take it for a drive to get it warm, then check for water leaks again. In the case of the 4-speed, if it won't kick down you most likely wired up the gearbox TPS switch wrong.
Moving Distrubutor PLugs Around
OK if you had troubles with your dizzy position here's what you do.
Going off the plug leads on top of the dizzy, mark one of the leads. Now determine how many leads you have to move it so that it's out of the way, and one of the leads is exactly where the marked one was.
Now being careful not to lose the order, change the position of the marked lead on the dizzy cap until the marked lead is on the post now occupying it's old position. Move the other leads accordingly. This should render the timing similar to what it was. Try to run the engine.
If it runs, but badly, loosen the retaining clip and slowly twist it until the engine runs at its fastest speed. Keep it at idle.
If you had to move the leads, and now the car won't start, you are going to have to do a 'static time'.
The diistrubutor spins clockwise. The firing order is 1-5-3-6-2-4.
Find lead 1 and note where it is relative to the distributor body. Now take the rotor cap off and crank the motor until the timing notch meets the '0' indicator on the timing cover. This is TDC or Top Dead Centre. If you can't spin it with the belts, the bolt in the balancer is a 22mm socket.
Since the motor reaches TDC twice in a single cycle, you are looking at TDC at either the end of the compression stroke, when it should fire, or the end of the exhaust stroke, when it should not fire.
OK now if the rotor button is close to your number 1 lead, twist the dizzy to meet it. If not, rotate the motor until it hits TDC again. Is it any closer? If so, twist the dizzy to meet it.
Then put the cap back on and try to start it again. If it starts, twist the dizzy until it runs properly.
Now you can keep up with the N/A boys! Up the back.
