Fuel Injection System Musings

[Gary Lewis]

Back in the early 70's I attended a set of classes hosted by Digital Equipment Corp (DEC) and I remember quite well their projection for the size and power of computers. It wouldn't be long before we could have computers in cars! And then I thought about how a computer could control the engine, and got excited.

 

Given that, I've been interested in EFI for a long time. So I wanted to start this thread about the various EFI systems out there, what they can do, how they work, etc. (Note: This is not a debate about whether EFI is better than a carb, or vice versa.) And I invite any of you to explain what you know about EFI systems, ask questions, etc.

 

I'll start. As many of you know, I'm following in Bill/85lebaront2's footsteps and installing a Ford EEC-V system in Big Blue. Yes, Ford did make an EEC-V system for the 460, but they only sold it in California and only in 1996 and '97.

 

So our systems are essentially "bolt in", although the wiring part of that is somewhat complex as you have to interface the EFI wiring with the Bullnose wiring. But this thread is about the EFI systems themselves so we will stay away from that issue.

 

But, you might ask what the differences are between EEC-IV and EEC-V systems for the 460. (Note that I specified "for the 460" as there are a lot of differences in other vehicles and with other engines.) Basically the IV systems are speed density, and that means the computer says "Since I know everything about the engine and its intake and exhaust systems, if I know the RPM then I know the amount of air that it is ingesting." However, if anything is changed then the computer doesn't know the amount of air.

 

But on the V systems there's a mass air flow (MAF) sensor that tells the computer how much air is coming in, so within reason you can make changes. And that's one of the reasons I'm going that way since the cam isn't stock and I'm running headers.

 

Speaking of MAF sensors, there are sensors and then there are sensors. Bill has been working on a spreadsheet of several of them, which is shown below. It shows the voltage output vs the air flow, which is important as an EEC-V ECU needs to know what the curve of the MAF sensor is.

 

But this brings up a question of mine: Most of these MAF sensors go to maximum output of 5.00 volts at ~600 CFM. So what happens when the voltage no longer increases but the RPM, and therefore the air flow, continues to go up? Does the computer continue to adjust the AFR based on the O₂ results?

 

[85lebaront2]

A couple of things, first, the earlier Ford systems are what is called "speed density" these use a MAP (Manifold Absolute Pressure) sensor that along with a TPS (Throttle Position Sensor) and engine RPM let the computer decide how much fuel is needed. The other sensors used are ECT (Engine Coolant Temperature) sensor and IAT (Intake Air Temperature) sensor. These will modify the fuel program, richer with lower temperatures, leaner with higher temperatures. These systems were the EEC-IV (Electronic Engine Control 4)

The SD truck systems were all what is called "bank fired" meaning the injectors, even though there are 6 or 8 of them are fired in banks of either 3 or 4 depending on the engine. Supposedly the F100s with the 3.8L V6 had a TBI (Throttle Body Injection) system, but like carbureted 1985 5.0L V8s, are a unicorn. The V8s all were wired the same way, 4 end and 4 center injectors, and the 4.9L sixes were split odd and even (1,3,5 and 2,4,6). In 1994 Ford started MAF (Mass Air Flow) SEFI (Sequential Fuel Injection) on 5.0L with the AOD, AOD-E, 4R70W and E4OD transmissions, manual transmission and C6 transmission models stayed SD/BF. In 1995 the same changes were made to the 5.8L engine trucks. These 1994/1995 systems still used the EEC-IV computers

In 1996, OBD-II was mandated for all vehicles under 8500 lbs GVW, Ford introduced the EEC-V system which, as part of the Federal mandate, has a computer that can be "reflashed" by the dealers or anyone possessing the proper hardware and software. Prior to this, the only way to update the computer's programming was to replace it. Aftermarket companies came up with a workaround involving a piggyback tuner, examples being Moates Quarterhorse or TwEECer. The Moates unit is a board that fits inside the case and plugs into the main board where the J2 port (rubber or plastic plug) is opposite the 60 way connector, the TwEECer plugs in from the outside. One of the glitches with the TwEECer, if it comes loose with the ignition on, it can fry the computer. Advantage to the TwEECer and maybe the Moates is the ability to have multiple tunes available. Since the 7.5L engines were relegated the the over 8500 GVW trucks, other than California and some New England states, they remained OBD-I and still used the EEC-IV computers with SD/BF controls.

One of the improvements with OBD-II was the change from a single O2 sensor to dual O2 sensors for the control and a 3rd one post catalytic converter for measuring efficiency. The dual, or stereo as they are sometimes called is the ability to "tweak" the mixture on individual cylinders as the system is fast enough at lower RPM to determine which cylinder was too rich or lean.

Once the throttle is wide open, the system goes to a predetermine WOT program, no O2 input, essentially just rpm based using injector size, cylinder volume and a calculated air density to obtain 12.5:1 AFR (Air Fuel Ratio). On an SD system, the MAP sensor lets the computer know if the air flow is decreasing relative to the rpm as the pressure will slowly drop as the intake system approaches it's limits. The MAF will measure the air flow up to its designed limit (roughly 500 cfm for the 80mm on the 5.0 and 5.8L engines and 600 cfm for the 900mm on the 7.5L engines). Again the system at WOT runs off a set of tables of which the air density is based on what the MAF was reading, the rest are hard programmed into the computer.

Other than Ford, Chrysler used SD controls up into the mid 2000s and possibly later, GM uses a hybrid system, MAP sensor for low rpm sensitivity and an MAF for higher RPM control. Chrysler only used IAT on their turbocharged and intercooled engines for a long time. Ford also had some SD/SEFI systems on cars, most went away when the Mod Motors were introduced starting in 1991 on Lincoln Town Car and 1992 on Crown Victoria and Grand Marquis.

[Rembrant]

Gary,

I saw a comment on one of the Facebook Bullnose groups the other day where a guy said, "Why on earth would anybody buy an archiac device like a carburetor when there are so many aftermarket EFI systems available that work so much better?". I didn't read the comments, but the obvious answer is price, if not simplicity, or both of those things together. I thought your thread was timely considering this was fresh in my mind from the past couple days.

Prior to me turning back in time and buying my 1984 Bullnose project in 2017, I had played around with ECU tuning in everything that I had owned for years previously. Anything that I could buy software for, I did, and used it too (Cars, and EFI motorcycles mostly). Problem is, the newer the vehicle is, the less improvements there are for the vehicle owner to make....you're basically left removing emissions tunes, or safety tunes (rev limiters or speed limiters). Still, they were fun to play with.

I may still install and aftermarket EFI system in my current project with the freshly rebuilt 5.0L engine. Time (and pocketbook) will tell. I will be installing a transmission controller for the 4R70W, and since there is no kickdown rod or cable like on older transmissions, I'll have to install a TPS on the side of the carburetor. That in itself has me thinking to just go with EFI, and make the complete jump...since the EFI TPS with interface with the transmission stand alone controller. Theoretically, they should work seamlessly together.

 

[85lebaront2]

Gary,

I saw a comment on one of the Facebook Bullnose groups the other day where a guy said, "Why on earth would anybody buy an archiac device like a carburetor when there are so many aftermarket EFI systems available that work so much better?". I didn't read the comments, but the obvious answer is price, if not simplicity, or both of those things together. I thought your thread was timely considering this was fresh in my mind from the past couple days.

Prior to me turning back in time and buying my 1984 Bullnose project in 2017, I had played around with ECU tuning in everything that I had owned for years previously. Anything that I could buy software for, I did, and used it too (Cars, and EFI motorcycles mostly). Problem is, the newer the vehicle is, the less improvements there are for the vehicle owner to make....you're basically left removing emissions tunes, or safety tunes (rev limiters or speed limiters). Still, they were fun to play with.

I may still install and aftermarket EFI system in my current project with the freshly rebuilt 5.0L engine. Time (and pocketbook) will tell. I will be installing a transmission controller for the 4R70W, and since there is no kickdown rod or cable like on older transmissions, I'll have to install a TPS on the side of the carburetor. That in itself has me thinking to just go with EFI, and make the complete jump...since the EFI TPS with interface with the transmission stand alone controller. Theoretically, they should work seamlessly together.

I looked at the options when deciding what I wanted to do on Darth, in theory I could run an AOD with adapter behind a 460. Problem is 6400 lb truck that can tow 10,000 lbs + a load. Having owned a truck with a 300 and C4 and knowing that the AOD innards aren't much bigger than a C4 I knew I needed something beefier. I found in researching things that an E4OD is a wide ratio C6 with an OD gear set in front of that and a lock up torque converter. Problem #1, E4OD stands for Electronic 4 speed Overdrive, the key word being electronic. At a minimum it requires a stand alone controller which at the time I was researching it, only Baumann controls built one and it was at that point $1500.

I also wanted to resolve the issue with hard starting after sitting, hard to find in-tank fuel pumps, leaky valve cover gaskets, dual air pumps and affiliated plumbing, weak FS-6 AC compressor and a few other issues due to the shoehorn job Ford had to due fitting the 460 in that chassis. Additionally the damage where the previous owner "parked by feel". I discovered a friend had a 1990 F250 he wanted to sell, it had a problem with #5 cylinder using oil and had been told it was a problem with the cylinder head. We agreed on a price of $850 and he would deliver it from Virginia Beach to Newport News. It had good front sheet metal and the 460/E4OD combination. Win - Win.

I swapped the top end of the engine over after finding no problem with the heads (they had been rebuilt) Oil consumption was caused by bad rings in #5, which is a chronic problem on the SD/BF 460s probably due to fuel rail design, firing order and heat. I swapped the C6 for the E4OD, had the front half of the driveshaft shortened and stripped the 1990 truck as much as I could use. I was going to use the steering column and dash, but found that I could use a newer (1995/1996) dash and stub column along with the newer parking brake self adjusting pedal. This solved the computer to run the transmission issue. I was digging into tuning both engine and transmission using a TwEECer and was having a problem finding anything as far as what and how for tuning when I was contacted in a Yahoo group, EEC Tuner by one of the principles in Core Tuning LLC who sold me a package consisting of an EEC-V computer, tuning software and a cable to interface with an OBD-II test port so that is what I have, and what Gary has, except he doesn't need the E4OD capability.

[Gary Lewis]

I looked at the options when deciding what I wanted to do on Darth, in theory I could run an AOD with adapter behind a 460. Problem is 6400 lb truck that can tow 10,000 lbs + a load. Having owned a truck with a 300 and C4 and knowing that the AOD innards aren't much bigger than a C4 I knew I needed something beefier. I found in researching things that an E4OD is a wide ratio C6 with an OD gear set in front of that and a lock up torque converter. Problem #1, E4OD stands for Electronic 4 speed Overdrive, the key word being electronic. At a minimum it requires a stand alone controller which at the time I was researching it, only Baumann controls built one and it was at that point $1500.

I also wanted to resolve the issue with hard starting after sitting, hard to find in-tank fuel pumps, leaky valve cover gaskets, dual air pumps and affiliated plumbing, weak FS-6 AC compressor and a few other issues due to the shoehorn job Ford had to due fitting the 460 in that chassis. Additionally the damage where the previous owner "parked by feel". I discovered a friend had a 1990 F250 he wanted to sell, it had a problem with #5 cylinder using oil and had been told it was a problem with the cylinder head. We agreed on a price of $850 and he would deliver it from Virginia Beach to Newport News. It had good front sheet metal and the 460/E4OD combination. Win - Win.

I swapped the top end of the engine over after finding no problem with the heads (they had been rebuilt) Oil consumption was caused by bad rings in #5, which is a chronic problem on the SD/BF 460s probably due to fuel rail design, firing order and heat. I swapped the C6 for the E4OD, had the front half of the driveshaft shortened and stripped the 1990 truck as much as I could use. I was going to use the steering column and dash, but found that I could use a newer (1995/1996) dash and stub column along with the newer parking brake self adjusting pedal. This solved the computer to run the transmission issue. I was digging into tuning both engine and transmission using a TwEECer and was having a problem finding anything as far as what and how for tuning when I was contacted in a Yahoo group, EEC Tuner by one of the principles in Core Tuning LLC who sold me a package consisting of an EEC-V computer, tuning software and a cable to interface with an OBD-II test port so that is what I have, and what Gary has, except he doesn't need the E4OD capability.

Cory - I agree. Placing a TPS on a carb is crazy. Go EFI.

Bill - I don't need to control an E4OD - YET. But I have an E4OD bolted up behind the 400 in Dad's truck. And I own a TFI Cleveland intake with the injector bungs cast in, and with the M-Block to Cleveland adapters I plan to have a full MAF/SEFI 400. So Big Blue is the pilot program and Dad's truck will follow. Both will have OBD-II ports so my offspring can have them maintained.

And to speak to some of what Bill said, the EEC-V system can have the rear O2 sensor turned off, which I've done in my ECU. And it can have the crank sensor, EGR, AIR solenoids, and other things like that turned off, which I've done. So on Big Blue I'll be running a very plain vanilla EFI system with two O2 sensors, engine coolant temp, inlet air temp, and mass air flow inputs.

And once I get that figured out I'll create another ECU with similar parameters but turn on the E4OD controls for Dad's truck.

[ratdude747]

Cory - I agree. Placing a TPS on a carb is crazy. Go EFI.

Bill - I don't need to control an E4OD - YET. But I have an E4OD bolted up behind the 400 in Dad's truck. And I own a TFI Cleveland intake with the injector bungs cast in, and with the M-Block to Cleveland adapters I plan to have a full MAF/SEFI 400. So Big Blue is the pilot program and Dad's truck will follow. Both will have OBD-II ports so my offspring can have them maintained.

And to speak to some of what Bill said, the EEC-V system can have the rear O2 sensor turned off, which I've done in my ECU. And it can have the crank sensor, EGR, AIR solenoids, and other things like that turned off, which I've done. So on Big Blue I'll be running a very plain vanilla EFI system with two O2 sensors, engine coolant temp, inlet air temp, and mass air flow inputs.

And once I get that figured out I'll create another ECU with similar parameters but turn on the E4OD controls for Dad's truck.

Keeping an eye on how Big Blue turns out in regards to EFI... Assuming I do end up with a 460 truck for a project, an EFI conversion is one possible route if the stock setup (or whatever it has) can't be made to work or is underwhelming. But I'm leaning more towards a sniper TBI and hyperspark ignition ($2000ish, but is a nice setup from the ones I've seen done already)... Don't get me wrong, I like my OBDII on the '95 Ranger, but the sniper ecosystem does have options to do a lot of the same stuff I'd be doing with OBDII (they even make 5" monitors to add to your dash!). And it's mostly bolt on and plug-and-play parts... biggest "pain" would be adding the wideband O2 (they give a clamp on solution, nah, I'd weld it).

[Gary Lewis]

Keeping an eye on how Big Blue turns out in regards to EFI... Assuming I do end up with a 460 truck for a project, an EFI conversion is one possible route if the stock setup (or whatever it has) can't be made to work or is underwhelming. But I'm leaning more towards a sniper TBI and hyperspark ignition ($2000ish, but is a nice setup from the ones I've seen done already)... Don't get me wrong, I like my OBDII on the '95 Ranger, but the sniper ecosystem does have options to do a lot of the same stuff I'd be doing with OBDII (they even make 5" monitors to add to your dash!). And it's mostly bolt on and plug-and-play parts... biggest "pain" would be adding the wideband O2 (they give a clamp on solution, nah, I'd weld it).

There are advantages and disadvantages to each of the many EFI solutions. But, from my understanding, only a factory system gives OBD-II. And I want my trucks to have that feature as I want my offspring to be able to have them maintained. (Not do it themselves, but have them maintained.)

Yes, the various aftermarket systems have the ability to connect some kind of device to them and find out what the problem is, but those are proprietary systems and I want the kids to be able to take the truck anywhere to have it serviced. So I've chosen to go with EEC-V - especially since Dad's truck has an E4OD that requires some kind of controller, which the EEC-V has.

But an aftermarket system would be easier to add on to an older vehicle if it didn't need the transmission controller. They come with a wiring harness, or harnii, and you put things in place and connect them up. Instead, I'm trying to figure out how to interface the new to the old. You could do it, but is that where you want to spend your time?

But, I'll bet that you can also make the carb system on that 460 work. It is a simple carb with a DS-II ignition system. However, the fuel system can be a pain depending on whether it has a mechanical fuel pump, which a few had, or the electric pumps.

Still, a TBI system, and especially one that controls the ignition, would be nice. Most of the advantages of port-injection EFI w/o the pain of individual injectors which require a special intake manifold, fuel rail, and wiring.

[Pete Whitstone]

Problem #1, E4OD stands for Electronic 4 speed Overdrive, the key word being electronic. At a minimum it requires a stand alone controller which at the time I was researching it, only Baumann controls built one and it was at that point $1500.

Not sure if you were looking at the Quick 2, 4 or 6, but I have the Quick 2 controlling my E4OD. I bought the controller, harness and a TPS for a Holley carb for $780 last fall, so these prices have come down considerably. I think the controller alone was about $540.

 

[85lebaront2]

Problem #1, E4OD stands for Electronic 4 speed Overdrive, the key word being electronic. At a minimum it requires a stand alone controller which at the time I was researching it, only Baumann controls built one and it was at that point $1500.

Not sure if you were looking at the Quick 2, 4 or 6, but I have the Quick 2 controlling my E4OD. I bought the controller, harness and a TPS for a Holley carb for $780 last fall, so these prices have come down considerably. I think the controller alone was about $540.

I do not believe any of those were out at the time I started planning this and executing it. I purchased the parts truck in March 2006 and started the serious execution in late 2010 and as I said, at the time it would require two separate aftermarket systems at roughly $1500 - $2000 each, then I would still have to purchase an E4OD. I also had to have a pair that could talk to each other.

Buying the 1990 F250 gave me a running package for $850 with the added advantage of front sheet metal and wiring harnesses. I took the 1990 rear chassis harness and added the 35" to make it fit a crew cab. After I had decided on using the 1996 interior I changed the front end from the 4 round 8 pin connectors and one round 4 large pin connector to the oval 24 pin one in the firewall.

The original continuous dash/front harness was replaced with the 1996 front harness with a 76 pin connector through the firewall to the 1996 dash harness. The EEC is mounted as close as I could get it to the 1992-97 location, almost in the left air box and it's 104 pin connector is right next to the 76 pin one.

Cost on a lot of this has come way down, but another consideration for me, I do not like TBI systems, they are nothing more than a pressure carburetor (WWII aircraft engine usage) and not true fuel injection.

 

[ratdude747]

There are advantages and disadvantages to each of the many EFI solutions. But, from my understanding, only a factory system gives OBD-II. And I want my trucks to have that feature as I want my offspring to be able to have them maintained. (Not do it themselves, but have them maintained.)

Yes, the various aftermarket systems have the ability to connect some kind of device to them and find out what the problem is, but those are proprietary systems and I want the kids to be able to take the truck anywhere to have it serviced. So I've chosen to go with EEC-V - especially since Dad's truck has an E4OD that requires some kind of controller, which the EEC-V has.

But an aftermarket system would be easier to add on to an older vehicle if it didn't need the transmission controller. They come with a wiring harness, or harnii, and you put things in place and connect them up. Instead, I'm trying to figure out how to interface the new to the old. You could do it, but is that where you want to spend your time?

But, I'll bet that you can also make the carb system on that 460 work. It is a simple carb with a DS-II ignition system. However, the fuel system can be a pain depending on whether it has a mechanical fuel pump, which a few had, or the electric pumps.

Still, a TBI system, and especially one that controls the ignition, would be nice. Most of the advantages of port-injection EFI w/o the pain of individual injectors which require a special intake manifold, fuel rail, and wiring.

My opinion: OBDII or not by the time your kids have it they'll have a fun trip finding someone willing to work on it either way. A lot of mechanics and shops frown upon dealing with somebody else's custom work... And the ones who do would likely be just as fine with an off the shelf Holley or Edelbrock kit. That said, part availability likely is better for the EEC-V setup... Pick your poison.