I Finally Did It.....EFI

[64fury74charger]

There is a bit of a learning curve when going from a low pressure, carbureted, mechanical fuel system to a high pressure, EFI, computer controlled system.
First, don't think of EFI as a carb replacement, you really are changing the entire fuel system. The fuel pumps, regulators, filters, pump locations, fuel lines, will be different, and usually EFI will also use a return fuel line from the regulator.
The high pressure EFI fuel pumps are not good at creating suction. An In-Tank pump is usually the best, quietest, and adds lift to the pump. Most In-tank pumps come with an inlet sock type filter. If using an external pump, it should have a low restriction 100 micron or less inlet filter. Pump outlet filters are usually 10 micron, and I think Holley says max of 30 micron? The pump outlet side is high pressure, usually 3 or 4 Bar (43.5 psi or 58 psi) on normally asperated engines, and higher on boosted engines. The fuel lines, connectors, clamps, and fittings need to work with the higher pressure (and with todays alcohol enhanced fuels.) Most (if not all) aftermarket EFI conversions are setup to use -AN fittings too.
Using your old corroded fuel lines with EFI can be a problem if it is past the fine filter. Any crud that gets past the fine filter can clog up an injector.
Carbs can run OK with some sediment that gets into the fuel bowl.
If your used of seeing a constant fuel pressure going to your carb, the EFI fuel pressure will vary depending on manifold vacuum/pressure.

Anyhow, I think the fuel system is where many people new to EFI make mistakes to where they complain they have a "bad injector" when it is likely has trash in it from the old fuel system. I think the electrical wiring most people handle fairly well, but get lost with the EFI terminology used for programming/tuning the ECU software.

I would agree that it seems like a large number of people are actually expecting these after market efi kits to be a simple days time to install and somehow miraculously work perfect without having any idea how efi works in the first place.

Prior to the efi install I have spent considerable time and money going through the electrical system and the charging system among other parts of the car. I have completely replaced the entire fuel system from the new tank with internal pump and the fuel lines and the 10 micron fuel filter and used AN fittings which are really nice to work with. The last thing you want is any contaminated crap in your fuel system.
Clean power and clean solid grounding is critical and isolating different wiring related to the efi. This is ASSUMING the mechanicals are in working order.

 

[threewood]

One weird issue I ran into and solved. Once I got my car here in NM and started driving it around I started getting a surge in RPMs. It would surge then calm down randomly.

I checked the vacuum hoses, pcv hose, fittings but nothing was loose or missing. So the next time it happened I watched my controller and the IAC would bump from 0% to 50% and back to 0%. So I unhooked the sensor and the surging stopped. Plug it back in and it surged.

So I got into the menu and found an IAC tab that had an IAC A/C kick, which was set at 50%. I set the value to 0% and no more surging. Not a clue how it turned on and became an issue after a year but that was the fix.

 

[davek]

what is the IAC A/C kick used for?

 

[threewood]

what is the IAC A/C kick used for?

It adds rpms to the idle when the A/C kicks on to keep the motor from dying.

 

[Cranky]

It adds rpms to the idle when the A/C kicks on to keep the motor from dying.

Used to have a 1990 Dakota where the AIC kept acting screwy so I just disconnected it all together and took it off. Even found an adjustable screw on the throttle body where I could adjust the idle up so it wouldn't die once the AIC was gone. The AC didn't have enough drag to cause the engine to die either and the computer didn't seem to care about the AIC being gone.

 

[Loren White]

I finally gave in to the dark side. Purchased a Holley Sniper EFI for my GTX. I've been having a weird lean pop at mid-low rpm that I just cannot tune out on my Edelbrock AVS carb. Said "F' it and bought it.

I already have the Holley Sniper EFI gas tank with 255 Walbro pump and an o2 sensor installed so it should make for an easy swap. I went with the EFI 4150 550-516 unit. 800cfm and good to 650 hp. Has a built in pressure regulator and is what sold me on it.

Going to document my install as I go. I'm curious as to how my throttle and kickdown stud fit. I am assuming I'll have to tweak it.

View attachment 1037855

What +12v source did you hook the pink wire to? I'm having trouble with my install. The car starts and dies indicating the system is not synching and there is no RPM to read.

 

[Loren White]

Nice, thanks! I have a Holley Street Dominator, 1" spacer and the throttle cable is 1" longer than stock. Still have some bend in it.

What did you use for the +12v switched source? I can't seem to find anything in my fusebox that is sufficient.

 

[Loren White]

Nice, thanks! I have a Holley Street Dominator, 1" spacer and the throttle cable is 1" longer than stock. Still have some bend in it.

What did you use for the +12v switched source?

 

[Loren White]

I finally gave in to the dark side. Purchased a Holley Sniper EFI for my GTX. I've been having a weird lean pop at mid-low rpm that I just cannot tune out on my Edelbrock AVS carb. Said "F' it and bought it.

I already have the Holley Sniper EFI gas tank with 255 Walbro pump and an o2 sensor installed so it should make for an easy swap. I went with the EFI 4150 550-516 unit. 800cfm and good to 650 hp. Has a built in pressure regulator and is what sold me on it.

Going to document my install as I go. I'm curious as to how my throttle and kickdown stud fit. I am assuming I'll have to tweak it.

View attachment 1037855

What +12v switched source did you use. I'm having trouble with that aspect on my install. Car starts and dies.

 

[threewood]

What +12v source did you hook the pink wire to? I'm having trouble with my install. The car starts and dies indicating the system is not synching and there is no RPM to read.

I hooked into the right side of the ballast resistor (my resistor is gutted with a solid wire).

 

[Loren White]

Used to have a 1990 Dakota where the AIC kept acting screwy so I just disconnected it all together and took it off. Even found an adjustable screw on the throttle body where I could adjust the idle up so it wouldn't die once the AIC was gone. The AC didn't have enough drag to cause the engine to die either and the computer didn't seem to care about the AIC being gone.

I hooked into the right side of the ballast resistor (my resistor is gutted with a solid wire).View attachment 1681902

I have the two plug ballast resistor. So I plug into the blue wire?

 

[threewood]

I have the two plug ballast resistor. So I plug into the blue wire?

Yes. If your ballast is still stock it may not work. I'm running a Pertronix III ignition which does not require the ballast. I have never had starting issues.

 

[rmchrgr]

Did you tie IGN 1 and IGN 2 together? The car may crank but when you release the key it will die. With any Holley/MSD type ignition those two circuits (crank and run) can’t have a break in them and must receive a continuous 12v in each position.

Like 3 wood said, the stock ballast resistor will lose voltage on one side when the key is in crank or run.

 

[beanhead]

My opinion...you should seriously consider eliminating the stock ignition setup with the EFI anyway.
Keeping the factory ignition negates a major benefit of swapping to EFI, which is computerized timing control. It's worth the extra money.

Tying IGN 1 & 2 together has worked fine for some, for others not so much.

If you choose to use the stock system, and it's not working for you then you might have to get a little creative and do something like use a starter button (mounted inconspicuously under the dash or somwhere else). Feed one side of the button with power from the 'run' terminal on your igntion switch (that's your switched power) and connect the yellow wire that goes out to the start relay to the button's other terminal. Now your key can stay in the 'run' position at all times.
You get in the car, switch the key to 'run', let 'er prime, hit the start button and whammo she fires up without having to break the switched power source to your EFI ECU.
There's other ways to do it, that's just one example of course....

 

[451Mopar]

On the '69 Coronet and '71 Charger tying Ign1 & Ign2 together worked.
I'm thinking of using a relay with a few modifications to be the EFI power-on source to cleanup any small power dropouts from the ignition key.

 

[rmchrgr]

The pic below is how I tied IGN 1 and IGN 2 together, right at the ignition switch. (I make my own wiring harnesses) The loop of brown wire between the two terminals prevents any break or voltage drop out between crank and run. This is a '68 switch which is in the dash. I'm not sure if the '69 switch is in the column but it definitely is on '70-up models. It's the same idea regardless - directly bridging the two circuits on the back of the switch (wherever it may be located) is (at least IMO) the best way to do it. I have zero concern that having full voltage between the two tabs is problematic since it's only momentary. That also allows one to remove any unecessary wiring if that's something you want. I definitely like that part of it.

Again, as with any Holley or MSD type ignition, the control box wants the full 12v in both the crank and run positions of the switch with no break between the positions. The stock ignition setup is literally the opposite of that. Back in the late '50s-early '60s the ballast resistor was put in the circuit to prevent full-fielding the coil and burning up the points on startup. By nature, the B.R. shunts voltage to one side of the ballast until the car fires. All that is out the window with a solid-state/digital box though as they are not designed with that arrangement in mind. Make no mistake - on a muscle-era Mopar, IGN 1 and IGN 2 HAVE TO BE TIED TOGETHER or the system will not work.

Plus, like beanhead suggested, there's really no point in trying to use the stock ignition with EFI - you're effectively defeating one of the main benefits of the conversion which is having the ECU control the timing. I don't like to spend other people's money but it is best practice to get all the EFI components at one time and install everything as a whole so there's no half-assery or compromises. It will reduce aggravation and failures.

The point being though, making adjustments through the ECU/software is infinitely more precise than turning the distributor. The software gives you the ability to adjust indivdual cells so no welding advance slots or what have you as you can literally make the timing do whatever you want at any given point on the curve. There's no substitute for that kind of finite adjustment as is removing mechanical slop from the equation.

Once the user gets into making their own ignition and fuel tables that concept becomes very clear.

 

[Dennis H]

Pro Flo 4 is a complete system, ahead of firewall. Fuel Rails deliver oem performance. Others are simply electric carburetors. As said, the grief is from there back. Since efi, no oil consumption.

 

[rmchrgr]

Pro Flo 4 is a complete system, ahead of firewall. Fuel Rails deliver oem performance. Others are simply electric carburetors. As said, the grief is from there back. Since efi, no oil consumption.

Any throttle body-based system is going to be similar including the Pro Flo 4 whether it has fuel rails or not. In both cases the T.B. feeds a plenum intake, the injector pulse just comes at a different point. I've read the Pro Flo is only rated at 35 psi while the Holley is 60 which is a big difference. Most modern OE fuel injection is 60psi.

Holley has a ton of support and parts. I really don't see many Edelbrock Pro Flo users out there especially at the drags. Most of the really fast EFI racers use the Holley Dominator system. Obviously the Sniper is not the Dominator at all but the software is the same. I don't know anything about the Pro Flo software (if it even has it) but the Holley software is really good. If the Pro Flo software has advanced it might be a consideration now but until then I wouldn't even consider it.

Every system has pros and cons though. Just have to educate yourself before you take the leap. Wiring and ego is what trips up most retrofit EFI installs.

 

[Dennis H]

Edelbrock is a complete system. Street car. Reliable

 

[rmchrgr]

Edelbrock is a complete system. Street car. Reliable

I drove my Sniper-equipped '68 Coronet for 1,000s of miles over three years before I sold it last August. Seemed pretty reliable to me.

One thing I can say with the Edelbrock system is that doing everything through a phone app would drive me absolutely bonkers. Yes, having a laptop in the car can be a bit clunky sometimes but once the tune is sorted out it's no longer needed. Changing stuff like learn table values or A/F ratios "on the fly" with the software is a really useful tool to have. And after my tune was locked in I hardly ever looked at the little handheld screen either, I just drove.

IMO, having the ability to create custom fuel and timing tables is really what makes EFI shine and I don't believe the Edelbrock app has that capability. Correct me if I'm wrong but the app seems based on choosing "X" tune with some amount of adjustability made available to the user. That's a deal breaker for me. Even if I don't ever use the Holley system to the fullest potential it's nice to have the capability on tap when needed. Not sure if the Edelbrock app can control stuff like a trans cooler fan or Nitrous but the Holley can certainly do all that stuff.

Whatever floats your boat I guess. If the Edelbrock system works for you and makes driving your car more enjoyable, that's all that matters.