I'm fitting fuel injection to my 68 Charger, with a view to getting better driveability - i.e cold starts, hot idling . And just a bit of a general experiment .
I'm using the FAST EZ-efi system , which is basically an electronic carburettor (throttle body) . The computer comes preset with a standard map, and self-learns as you drive by constantly reading a number of sensors. The EZ-efi setup doesn't control ignition timing - it just functions as a fuelling system.
Stuff to do :
1) Upgrade ignition system
2) Upgrade charging system
3) Fuel tank & pump
4) Fuel & return lines
5) Locate control unit & do wiring.
6) Fit Throttle body
pics & writeup to follow .
Matt's Charger , Fuel Injection conversion
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Matt's Charger , Fuel Injection conversion
Last edited by Matt on Mon Feb 27, 12 9:32 am, edited 2 times in total.
Ignition system :
The car currently has an FBO-curved Mopar electronic distributor, and a Mopar orange box.
THe efi brain needs a clean, accurate tach signal from the ignition, as this is how it reads engine rpm. You can use a separate adaptor (supplied) on the Mopar system , or fit an aftermarket ignition such as MSD .
I chose the MSD 6A to be sure of getting a clean tach signal, and hopefully better ignition performance in general. I've heard a few reliability concerns about the MSD units, but many of these can probably be put down to bad luck or bad installs.
The MSD box fits nicely under the battery tray, and this location also makes wiring fairly straightforward - you can see the loom coming up the inner wing between the shock tower and the battery. Sorry about crap pics.
The MSD box wires straight in to the existing Mopar electronic distributor. I fitted an MSD coil as well, and removed the ballast from the ignition circuit, as the MSD unit doesn't need it.
The car currently has an FBO-curved Mopar electronic distributor, and a Mopar orange box.
THe efi brain needs a clean, accurate tach signal from the ignition, as this is how it reads engine rpm. You can use a separate adaptor (supplied) on the Mopar system , or fit an aftermarket ignition such as MSD .
I chose the MSD 6A to be sure of getting a clean tach signal, and hopefully better ignition performance in general. I've heard a few reliability concerns about the MSD units, but many of these can probably be put down to bad luck or bad installs.
The MSD box fits nicely under the battery tray, and this location also makes wiring fairly straightforward - you can see the loom coming up the inner wing between the shock tower and the battery. Sorry about crap pics.
The MSD box wires straight in to the existing Mopar electronic distributor. I fitted an MSD coil as well, and removed the ballast from the ignition circuit, as the MSD unit doesn't need it.
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- IMG_0535.JPG (117.24 KiB) Viewed 1298 times
Charging system
THe efi fuel pump, brain , MSD etc will draw a lot of current at idle . maybe ten, fifteen amps. It's also not going to tolerate much in the way of voltage drop. So the original charging system will have to go .
I fitted a Powermaster 140 amp 1-wire alternator . It bolted straight up to the engine with just a few mods- I had to fabricate a new belt tension adjusting strap.
Then I ran a heavy cable straight to the positive battery terminal. I haven't fused this cable yet but may well do in the future.
This new arrangement means that no charging current is now passing though the bulkhead connector ( a good thing, as 140amps full charge would fry the connector and/or the factory ammeter)
So I rewired the bulkhead connector to take account of this, and also made up a new engine wiring loom - as there are no longer any wires required in it for : Voltage regulator, ballast resistor, charging system.
The dash ammeter will not function at the moment - I'll think about that later . I could convert it to work with the new system, or fit a voltmeter instead.
I fitted a Powermaster 140 amp 1-wire alternator . It bolted straight up to the engine with just a few mods- I had to fabricate a new belt tension adjusting strap.
Then I ran a heavy cable straight to the positive battery terminal. I haven't fused this cable yet but may well do in the future.
This new arrangement means that no charging current is now passing though the bulkhead connector ( a good thing, as 140amps full charge would fry the connector and/or the factory ammeter)
So I rewired the bulkhead connector to take account of this, and also made up a new engine wiring loom - as there are no longer any wires required in it for : Voltage regulator, ballast resistor, charging system.
The dash ammeter will not function at the moment - I'll think about that later . I could convert it to work with the new system, or fit a voltmeter instead.
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- red charging cable goes across front of K member
- IMG_0532.JPG (96.94 KiB) Viewed 1288 times
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- cable from K member up to battery
- IMG_0533.JPG (102.62 KiB) Viewed 1287 times
smashin
if you have problems with tach signal the 4 pin HEI module off a 76-86 GM truck can be run in parralell just to drive your tach
check the megasquirt pages on GM 4 pin for wiring.
does this one need a special pump?
are you going to use old style pump to fill swirl pot and a efi pump from it to the throttle? of go full there and back lines to tank
great to see someone doing this
Dave
if you have problems with tach signal the 4 pin HEI module off a 76-86 GM truck can be run in parralell just to drive your tach
check the megasquirt pages on GM 4 pin for wiring.
does this one need a special pump?
are you going to use old style pump to fill swirl pot and a efi pump from it to the throttle? of go full there and back lines to tank
great to see someone doing this
Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
Hi Dave - you beat me to it !!
Fuel system : There's quite a lot of stuff to think about here .
Basic fuel system for this setup :
efi pump feeds bypass-type regulator in engine compartment . 100 micron filter pre-pump, 10 micron filter post-pump. Return from regulator feeds back to tank.
The main problem with retro-fitting an efi system to a standard car, is that fuel in the tank cannot be allowed to slosh away from the pickup (cornering, braking, etc) This is not a big problem for carburetted cars , as the float chambers in the carb act as a reservoir and keep the engine running until the fuel sloshes back around the pickup again. If the pickup is exposed on an efi car, fuel pressure to the injectors is lost instantly and the engine stops.
Two solutions:
1) Fit a swirl pot . this is a small reservoir fed from the main tank. Use a basic electric pump to keep the swirl pot full (fuel bypasses back to the tank from an outlet at the top of the pot) . THe feed to the efi pump is then taken from the bottom of the swirl pot . Since the swirl pot is a tall cylinder and is always full, the efi feed can't run dry under cornering/ braking forces.
2) Put the efi pump inside the main tank, drawing fuel from a sump. The return line from the regulator also exits into this sump, keeping it topped up.
Downsides to solution 1:
More plumbing
Find room for the swirl pot
Two fuel pumps required . Twice the failure possibility.
Downsides to solution 2:
A bit of fabrication . Cost of a new tank if you're scared of welding the old one (which I am) .
Fuel system : There's quite a lot of stuff to think about here .
Basic fuel system for this setup :
efi pump feeds bypass-type regulator in engine compartment . 100 micron filter pre-pump, 10 micron filter post-pump. Return from regulator feeds back to tank.
The main problem with retro-fitting an efi system to a standard car, is that fuel in the tank cannot be allowed to slosh away from the pickup (cornering, braking, etc) This is not a big problem for carburetted cars , as the float chambers in the carb act as a reservoir and keep the engine running until the fuel sloshes back around the pickup again. If the pickup is exposed on an efi car, fuel pressure to the injectors is lost instantly and the engine stops.
Two solutions:
1) Fit a swirl pot . this is a small reservoir fed from the main tank. Use a basic electric pump to keep the swirl pot full (fuel bypasses back to the tank from an outlet at the top of the pot) . THe feed to the efi pump is then taken from the bottom of the swirl pot . Since the swirl pot is a tall cylinder and is always full, the efi feed can't run dry under cornering/ braking forces.
2) Put the efi pump inside the main tank, drawing fuel from a sump. The return line from the regulator also exits into this sump, keeping it topped up.
Downsides to solution 1:
More plumbing
Find room for the swirl pot
Two fuel pumps required . Twice the failure possibility.
Downsides to solution 2:
A bit of fabrication . Cost of a new tank if you're scared of welding the old one (which I am) .
The EZ-efi system can use pretty much any aftermarket efi pump that can supply 43psi at the regulator.
I bought the recommended external pump with the system, then decided not to use it. Didn't fancy the extra complexity of the swirl pot system.
Tanks Inc in the US do a purpose built in-tank pump and sump kit. This uses the Walbro 255 pump which is factory fitted on many modern cars, and proven reliable. So I bought one of these, and a new tank.
I bought the recommended external pump with the system, then decided not to use it. Didn't fancy the extra complexity of the swirl pot system.
Tanks Inc in the US do a purpose built in-tank pump and sump kit. This uses the Walbro 255 pump which is factory fitted on many modern cars, and proven reliable. So I bought one of these, and a new tank.
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- IMG_0520.JPG (87.16 KiB) Viewed 1265 times
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- IMG_0519.JPG (92.41 KiB) Viewed 1265 times
A bit of measuring.
Try to decipher the instructions, including such nuggets as ' the reservoir must face left-right across the tank' . It's rectangular - how do I know which way it's 'facing' ????
Make sure you've cleared the standard pickup (which will be retained but blanked off)
Jigsaw hole, drill mounting holes . Deburr.
Try to decipher the instructions, including such nuggets as ' the reservoir must face left-right across the tank' . It's rectangular - how do I know which way it's 'facing' ????
Make sure you've cleared the standard pickup (which will be retained but blanked off)
Jigsaw hole, drill mounting holes . Deburr.
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- IMG_0525.JPG (95.7 KiB) Viewed 1256 times
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- IMG_0526.JPG (80 KiB) Viewed 1256 times
Because the pipe fittings are on the top of the tank now, the boot floor will have to be reshaped in this area . Not a big problem for me , as the floor needs replacing anyway.
The alternative would be to recess the unit into the top of the tank by 1.5" or so . Decided not to because :
1) I couldn't be bothered
2) The sealing gasket could end up below fuel level, and I wanted to avoid that if possible.
There's a retaining ring that mounts inside the tank - it's slotted so that you can guide it through the hole, and contains tapped holes for all the securing bolts. It's best tack-welded in place, although you can leave it loose if required.
The alternative would be to recess the unit into the top of the tank by 1.5" or so . Decided not to because :
1) I couldn't be bothered
2) The sealing gasket could end up below fuel level, and I wanted to avoid that if possible.
There's a retaining ring that mounts inside the tank - it's slotted so that you can guide it through the hole, and contains tapped holes for all the securing bolts. It's best tack-welded in place, although you can leave it loose if required.
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- IMG_0527.JPG (117.44 KiB) Viewed 1249 times
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- IMG_0523.JPG (72.72 KiB) Viewed 1249 times
At this point, you remember that you really need to get the swarf out of the tank.
Unfortunately the whole inside of the tank has a sticky oily film on it, and all the swarf has stuck to it .
Seal holes in tank , pour in degreaser, slosh around. Rinse out with water . Well that got nearly all of it out . Any remnants will just have to get caught in the pre-pump filter screen.
Anyway that's about where I'm at for now . I need to order some more stuff:
some 3/8" steel hard line for the fuel/ return lines
more -6 AN fittings of various types
some 10/32 UNF screws missing from the fuel pump kit.
Hope to post an update in a couple of weeks.
Unfortunately the whole inside of the tank has a sticky oily film on it, and all the swarf has stuck to it .
Seal holes in tank , pour in degreaser, slosh around. Rinse out with water . Well that got nearly all of it out . Any remnants will just have to get caught in the pre-pump filter screen.
Anyway that's about where I'm at for now . I need to order some more stuff:
some 3/8" steel hard line for the fuel/ return lines
more -6 AN fittings of various types
some 10/32 UNF screws missing from the fuel pump kit.
Hope to post an update in a couple of weeks.
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autofetish
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Rogue Trooper
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Thanks for all the interest.
Thought I'd fit the O2 sensor next.
Some O2 sensors have an internal electric heating element , some just use the exhaust heat to work.
The sensor with the FAST efi kit has the heating element, and it's recommended to fit it at least 20" away from the heads .
Any closer, it could get too hot . Too near the tailpipe, and the reading can be affected by outside air mixing with the exhaust gases.
Also the sensor should point downward from horizontal . This prevents moisture & condensation from accumulating inside it.
Found a suitable position just near the torsion bar mount. Had to drop the exhaust to get access to drill & weld.
There's a threaded bush provided in the kit to weld into the exhaust pipe. It looks to be stainless, but seemed to weld OK to the mild steel exhaust just using the MIG.
The sensor has a multipin connector , and just plugs into the efi loom .
Thought I'd fit the O2 sensor next.
Some O2 sensors have an internal electric heating element , some just use the exhaust heat to work.
The sensor with the FAST efi kit has the heating element, and it's recommended to fit it at least 20" away from the heads .
Any closer, it could get too hot . Too near the tailpipe, and the reading can be affected by outside air mixing with the exhaust gases.
Also the sensor should point downward from horizontal . This prevents moisture & condensation from accumulating inside it.
Found a suitable position just near the torsion bar mount. Had to drop the exhaust to get access to drill & weld.
There's a threaded bush provided in the kit to weld into the exhaust pipe. It looks to be stainless, but seemed to weld OK to the mild steel exhaust just using the MIG.
The sensor has a multipin connector , and just plugs into the efi loom .
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- o2 sensor.jpg (97.71 KiB) Viewed 1130 times
been thinking about going fuel injection for some years , ( thinking is all i ever seem do these days 
))
