Holley Sniper (aftermarket EFI), good or not?

[Vic Roma]

Is it worth keeping or removing an aftermarket Holley EFI module and return to stock carb on a 5.8? It functions perfectly fine, but I am toying with the idea, and wonder what the engine is like without the EFI. Is the EFI worth having? Does it matter either way?

[Jacob84]

If it is working properly I would keep it unless you’re trying to have a “numbers matching” truck. Not that carbs are bad, I love carburetors on some things, but EFI really extends the life and drivability of a motor. One example of this would be when you let off the gas in your truck. A carb will continue to allow fuel to into the motor while coasting which decreases economy and increases engine wear due to the excess amount of fuel. In an EFI system when the computer senses the throttle is closed and MAP is low it will cut the excess fuel, increasing economy (slightly) and decreasing engine wear because that fuel isn’t washing the oil off the cylinders. That’s one example. Typically properly tuned efi motors last longer.

Carbs are great, properly function aftermarket efi (Holley EFI) is better, and OEM EFI is best

That’s my opinion of course, maybe some others will weigh in.

I own an EFI system like you have but it’s made by FiTech for Summit Racing. I’ve done A LOT of research on these systems and now own one so if you need any help or have questions ask away, I might be able to help.

[Gary Lewis]

I agree.  But let me say it another way.  To me there are three levels of fuel systems:

Carburetors: They supply the correct air/fuel ratio at only one temperature and air pressure, and even then only if they've been finely tuned.  And the air/fuel ratio is not equally distributed to the cylinders due to the inequalities of the runners in the intake manifold.

Central EFI: Also known as throttle-body EFI, this is a carb replacement.  But it gets the average air/fuel ratio correct for all temps and air pressures, although it is still limited by the inequalities of the intake manifold.

Cylinder Injection EFI: This builds on the throttle body by placing injectors such that they inject into the cylinder through the intake valve's opening (port injection) or directly into the cylinder (direct injection).  It comes pretty close to getting equal distribution to all cylinders.

You have a good system, so why go back a step?  With the right air cleaner on it most people can't even tell.

[85lebaront2]

I agree with Gary on that. My opinion on central or throttle body injection systems, they are like aircraft "pressure carburetors". As long as the pump can draw fuel from the tank they will run at all sorts of angles and do a better job of atomizing the fuel than a carburetor.

Port injection systems, there are several styles, the simplest being a constant flow system, the earliest being the 1957 Chevrolet Rochester "Ram Jet" system, first it had a ram manifold design of 8 runners from a plenum for power, but the 8 injectors were all fed by a common source by a mechanical high pressure gear pump, metering was by a combination of manifold vacuum and air flow using a venturii for the flow signal. Bosch used a similar system called CIS, for continuous injection system. Bosch had an earlier system, electronic called D-Jetronic for manifold depression, this had a set of points in the bottom of the distributor to run the injectors in 4 groups of 2 on V8s (FWIW, same cylinder numbering as Ford, and firing order as flathead and Y-block). The system used a manifold pressure sensor and a fairly simple computer.

Ford EEC-IV systems can be either sequential or bank fired, cars usually had sequential unless they were the early TBI systems. Trucks were bank fired, and the banks are 4 end cyls. and 4 center cyls. Somewhere around 1988 Ford started changing from MAP sensors (Manifold Absolute Pressure) to MAF (Mass Air Flow) systems. It was started with the Mustangs, then migrated through other car lines, most when the Mod motors were introduced starting in 1991 with the Lincoln Town cars, and 1992 with the Crown Victoria and Grand Marquis models. Trucks began to see MAF/SEFI in 1994 on the 5.0L engines and electronic transmission controls, the last to get this were the 7.5L engines, and only on California under 14,000 GVW trucks.

Aftermarket systems frequently do not have the capability to control transmissions, particularly the full electronic ones like the 4R70/75W and E4OD or 4R100. These require a second computer for the transmission.

[Vic Roma]

Very informative responses, gentlemen.
Thank you.

Never having performed such an operation, I am sure that if I touched it, I would break it. Basis your opinions, I will leave it alone. I just don't like seeing the EFI wires criss-crossing under/over everywhere. It looks semi-unprofessional, and especially loathe all the cut vacuum hoses shoved wherever beneath the air cleaner and around the cylinder heads.

Gary, in my other post about the faulty turn signal, you can just see the corner of the air cleaner in one of the photos. It looks just like the photo below (not mine but taken from Google). Is this what you mean when you wrote "With the right air cleaner on it..."?

[Gsmblue]

Interesting discussion. I have an efi 302 and carbed 351. The efi starts first time every time. The carb, well it starts well but that electric choke needs seasonal adjusting and our temp swings a re big.. todays was a low of 17 and a high of 60.

I really like the principle of these efi units they replace carbs , i will be shopping for one later in the year!

[Gary Lewis]

Yes, that's basically what I meant about the air cleaner.  The central EFI systems are roughly the size of a carb and the air cleaner can easily hide them.

As for the vacuum lines and wires, if you are careful you can clean all of that up.

[85lebaront2]

That exact reason was part of why I converted Darth to EFI. At the time there were no true port injection systems other than OEM for the 460. As I discovered in researching things, the MAF/SEFI 460 was in the words of one person a "unicorn". The problem, all of them were California specific systems and only on E4OD trucks. I wanted MAF/SEFI as it isn't as sensitive to cam profile as a Speed Density (MAP sensor) system. There were never any truck systems with speed density SEFI.

The other issue came with the desire to add an OD transmission with a lock-up converter. The commonly used Mustang 5.0L EEC will not control an E4OD, the required circuits aren't there. My first shot was a 1995 Bronco 5.0L EEC, code WAY1 which will run an E4OD, my problem with that was shift points, the 5.0L is a relatively low torque high revving engine, I did not want to be buzzing a 460 up like that.

My system uses an EEC-V computer that I can reflash as needed and it controls the E4OD just fine. I have the torque converter clutch unlock set at 80% throttle and let the 460's torque do the work.

[Gary Lewis]

To echo what Bill said, I've learned from him and have EEC-V systems for both Big Blue and Dad's truck.   Big Blue won't get his for some time, but it has the E4OD controls turned off so I can run the ZF5 manual tranny.  And Dad's truck has the E4OD installed, but not the EFI yet.  Both are works in progress.

Now, to add to what Bill said, I believe EEC-V is the only way to get an operative OBD-II port on these trucks.  (While I think some of the EEC-IV's for the smaller engines came with an OBD-II port they weren't operative.  But it is true of the 460's.)  And I wanted OBD-II so my offspring can have the trucks I hand off to them maintained, and they aren't mechanics.  My thinking is that just about anybody has an OBD-II scanner, but the aftermarket is changing so rapidly that support for today's aftermarket EFI might not be available in 10 years.

[Vic Roma]

What are the cut vacuum lines for, if when they're not connected, the truck still runs, including all accessories, etc.?

[Gary Lewis]

We can't tell you that off the tops of our heads as we don't know what ones they used and what ones they didn't.  But, if you take good pics, and post them as large as you can on here, we might be able to figure it out.

Conversely, if they aren't connected and the truck runs well you can remove them w/o figuring out which ones they are.

My thoughts on which ones you need are shown here: Documentation/Underhood/http://www.garysgaragemahal.com/vacuum-systems.html.

[LARIAT 85]

Gsmblue wrote

Interesting discussion. I have an efi 302 and carbed 351. The efi starts first time every time. The carb, well it starts well but that electric choke needs seasonal adjusting and our temp swings a re big.. todays was a low of 17 and a high of 60.

I really like the principle of these efi units they replace carbs , i will be shopping for one later in the year!

I think it would be a lot easier and cheaper to fix your existing problem.

What kind of carburetor do you have, and what exactly is your truck doing that makes you think the choke needs seasonal adjustments?  

Are you using a stock style thermostatic air cleaner, or the open-element variety?

[Jacob84]

85lebaront2 wrote

The other issue came with the desire to add an OD transmission with a lock-up converter. The commonly used Mustang 5.0L EEC will not control an E4OD, the required circuits aren't there. My first shot was a 1995 Bronco 5.0L EEC, code WAY1 which will run an E4OD, my problem with that was shift points, the 5.0L is a relatively low torque high revving engine, I did not want to be buzzing a 460 up like that.

Not to hijack the thread but what were the shift points for the 95 Bronco PCM if you remember? Say at WOT? I have a 351w that makes peak power at around 5k, an E4OD in my shop, and all the extra hardware including wiring from a 95 f150.

[LARIAT 85]

Vic Roma wrote

Is it worth keeping or removing an aftermarket Holley EFI module and return to stock carb on a 5.8? It functions perfectly fine, but I am toying with the idea, and wonder what the engine is like without the EFI. Is the EFI worth having? Does it matter either way?

From a performance stand point, I don't think it matters that much either way.   All other things being equal, there isn't much difference between a properly-functioning EFI system and a well-tuned carbureted system.  That being said, I think it would be better to have a stock carbureted setup over an aftermarket EFI system.
 

Aftermarket EFI systems generally aren't as good as OEM.  And I would suggest that you learn to work on your own vehicle, because most mechanics do not want to mess with an aftermarket EFI system.  

Likewise, aftermarket carburetors generally aren't as good as OEM.  And I would suggest that you learn to work on your own vehicle, because many mechanics do not want to mess with a carbureted system at all (or don't know how), much less a custom job that was re-engineered by the owner with a bunch of custom and/or aftermarket parts.


It is much easier for you (and a mechanic) to be able to reference a shop manual to repair your vehicle.  The further away you get from stock, the harder that job becomes.