Why do people convert Injected 5.0s to carb?

Trackmouse said:

Duuuuuuuude!!!!1!!!! 70’s Corolla! It’s a no brainer! Fox body ain’t got the body of a Fox...

Ha ha. Some times my impatience gets me in trouble. A lot of (rusty) fox bodies, almost no 70s rollas around here. 

Somebeach said:

Wow.  What great responses. I never knew that there was such difference in opinions on this subject.  

To be honest, a lot of what is being discussed comes down to scenario and personal preference.

The fact is this- if time and cost are not issues with a build, EFI is superior to a carburetor in every way. Properly sorted, an EFI engine will be more "streetable" with no cold-start procedure, have greater fuel economy, and will give far more options (in terms of the potential posed by fuel mapping and E85) than an "equivalent" carb. HOWEVER, a carburetor will require far less setup (low pressure fuel pump means it's easier to convert an EFI tank to a carb than the other way around, a fraction of the wiring) and running one will not require a computer or some kind of dyno; most carb makers will help build your carb to be ran "out of the box" if you give them the finer details of your build, making a carb'ed car able to ran in an afternoon instead of (likely more than) several days with a proper EFI build.

Somebeach said:

Wow.  What great responses. I never knew that there was such difference in opinions on this subject.  

I don't know that I see many differences of opinion. We've all pretty much agreed that EFI is superior in every way except cost and simplicity. Different strokes for different folks as far as preferences go, but that's pretty much any subject.

Basically, many have carbs laying around or pick them up from friends/family or from the latest Jegs or Summit catalog.  Pretty simple, bolt on a mechanical pump, install intake/carb and linkage, start, set idle and drive around.  The rest is just tuning via jets and accel pump settings.

Carbs will run poorly pretty much forever and like has been mentioned, the OE EFI leaves something to be desired once you start making huge changes to the engine or just trying to repair it.

However, replacing that EFI controller with a modern solution like MegaSquirt can yield benefits that a carb can't and won't provide.  Many of the rest of 80-90's EFI parts are Bosch parts and can be interchanged with some or little effort.

Many of the limitations of a carburetor are also limitations with TBI due to wetting cylinders, achieving balance on all of the cylinders, etc.  Its slightly better for cold starting and similar drivability issues, but yeah if given the choice I'm not sure I'd mess with TBI over a carb except for what you're comfortable with.

Plus, sometimes you just *want* a car to be carbed. There is nothing wrong with restoring or building something a certain way due to nostalgia, so long as you're aware of it and accept it's limitations- that's what it means to be a true enthusiast.

At least where I'm at, the cost to have someone tune the factory EFI EEC-IV is $500.  Not including the chip, which is at least another $100.  Pretty much any cam/injector change, and you'll need it tuned to maximize its potential.  Nitrous, Turbo, Supercharger, all need tuned.  The EEC-IV EFI can be painful to diagnose compared to any OBD-2 set up.  You can DIY Meqasquirt it, they make a kit that uses the factory harness, but then you still rely on the troublesome Ford TFI distributor, pickup, TPS, O2's, etc.

I'm sure the TBI style self tuning EFI setups aren't comparable to a port injection, but it's beginning to be much more common on some SBF mustangs and toys here.  Especially compared to the Factory EFI. One factory chip tune and you're 60% there.

Also, if the fuel pump fails on a carbed engine you can rig up a jerry can to provide gravity fed gas. 

Just sayin.

HotNotch said:

At least where I'm at, the cost to have someone tune the factory EFI EEC-IV is $500.  Not including the chip, which is at least another $100.  Pretty much any cam/injector change, and you'll need it tuned to maximize its potential.  Nitrous, Turbo, Supercharger, all need tuned.  The EEC-IV EFI can be painful to diagnose compared to any OBD-2 set up.  You can DIY Meqasquirt it, they make a kit that uses the factory harness, but then you still rely on the troublesome Ford TFI distributor, pickup, TPS, O2's, etc.

I'm sure the TBI style self tuning EFI setups aren't comparable to a port injection, but it's beginning to be much more common on some SBF mustangs and toys here.  Especially compared to the Factory EFI. One factory chip tune and you're 60% there.

Ditch the factory ignition and have MegaSquirt control it.  You could even run distributorless as that was an option on Ford V8's.  You wouldn't want to use the stock O2 as you'd want to use a Wideband solution and those have dropped in price to reasonable prices now.  If the TPS is an issue, there are aftermarket throttle bodies or you could adapt a different TPS to the stock TB.  They are just potentiometers and MegaSquirt doesn't even really need them, but its better if they are there.

I had a conversation with a gentleman who built a GT40 replica.  It looked really good and very close to an original down to the Ford V8, downdrafts and bundle of snakes exhaust.  Except he's running DCNF-style throttle bodies and aftermarket EFI.  Not a cheap setup, but its infinitely more driveable than a similar car with a series of carbs.

Generally if a car came with factory EFI, it'll have a reasonable set of sensors, etc. to use to run Megasquirt or other aftermarket EFI.  So upgrading to something more tunable shouldn't be too painful.  

Some people just prefer simplicity.  Some people want to tune their car with a screwdriver, instead of a laptop.   Detractors make it sound like cars can't run well when carbureted.  Carbs worked well for about 100 years, they aren't voodoo magic--- they are simple to rebuild, set-up and run.   EFI takes an altogether different set of skills--- some of which are repellent to some enthusiasts.   Some folks don't want to break out the laptop to tune a car.  Some folks would rather work with mechanical systems, rather than electronic ones. 

With a malfunctioning carb, you can still get home.  With a malfunctioning EFI  you are stuck.    A properly tuned carb will allow a car to run very well for a long time.  They aren't as efficient as a properly tuned EFI system, but they work a lot better than an improperly tuned EFI system.

Different strokes for different folks.   I certainly wouldn't throw stones at anyone for choosing either.  It's personal preference. 

I have both a Holley 390, Webber 32/36, and matching intakes for my 2.3L mustang.  One will go on for next years racing season, our plugs are real white right now and the obd1 is not going to get hacked my me.   If I could find an adjustable fuel pressure regulator and some bigger injectors I may be able to make it work but why. 

We are going to carb to save weight, simplify and just because.  On a race car we don't need light throttle or cold weather drivability just partial to WOT jetting.  

Mine is EFI.  But entirely aftermarket.  The two piece intake manifold is weird and heavy, I can certainly see the appeal of a simple one piece with a 5 lb carb on top.

I've been looking at all of the options if I need to change out the 350 in my TBI 88 Silverado. 

Stock engine with the TBI, 350/383 with carb or aftermarket TBI, or LS like an LQ4 or LQ9. 

The 1988 factory TBI won't allow me to modify the engine like a sniper or fitech system, or carb would. I just don't want to go back to a carburetor. 

TheRX7Project said:

I don't know that I see many differences of opinion. We've all pretty much agreed that EFI is superior in every way except cost and simplicity. Different strokes for different folks as far as preferences go, but that's pretty much any subject.

You forgot power and weight also being generally easier, in this application, with a carb and proper intake manifold.

If we were talking about LSen, where there are plastic intakes with good sized everything out there in trucks, vans, etc for not a lot of money, this would probably not be the same kind of story.  I don't know that I personally would pull working EFI out of a 5.0 powered car but I can understand it, especially when mods come into the picture and the budget isn't so loose.  Honestly I don't think that, say, the intake on my long-gone 1995 Mustang GT is remotely superior to a carb intake from a company like Edelbrock, Weiand, etc.  "It doesn't flow that well, but at least it weighs a lot and is huge".

Floating Doc said:

I've been looking at all of the options if I need to change out the 350 in my TBI 88 Silverado. 

Stock engine with the TBI, 350/383 with carb or aftermarket TBI, or LS like an LQ4 or LQ9. 

The 1988 factory TBI won't allow me to modify the engine like a sniper or fitech system, or carb would. I just don't want to go back to a carburetor. 

If you like a project, what about a Tuned Port setup controlled by Megasquirt?  Lots of old hardware sitting out there and this setup makes good power and torque.

Cost and simplicity are higher on my priority list than top end performance. That being said, I have not converted any engines from an existing efi setup to a carb.

pres589 said:

Floating Doc said:

I've been looking at all of the options if I need to change out the 350 in my TBI 88 Silverado. 

Stock engine with the TBI, 350/383 with carb or aftermarket TBI, or LS like an LQ4 or LQ9. 

The 1988 factory TBI won't allow me to modify the engine like a sniper or fitech system, or carb would. I just don't want to go back to a carburetor. 

If you like a project, what about a Tuned Port setup controlled by Megasquirt?  Lots of old hardware sitting out there and this setup makes good power and torque.

I love the look of a TP system, and it would be a good package for this truck with a pair of decent heads and mild roller cam. Down side is that I would have to learn a whole new skill set with the MS, don't really have the time. I'm very ADD with projects too, good at starting them, not at finishing. If I had someone to coach me through it, I would consider it, but I'm not going to get it figured out reading forum discussions. That's how I learned to pull and replace the 302 in my ford, or swap head gaskets. 

I stuck with four barrels on that car because I could take one out of the box, drop it on the intake, and have it running in 30 minutes (plus the car was orginally a variable venturi carb set up). 

In reply to frenchyd :

Because 20+ mpg on the highway and good driveability in all conditions trumps carburetors.

I race and wrench on a carbureted hoopty in 24 hours of Lemons and my first car was  a 63 Fairlane. I know my way around carburetors. My preference is Autolite-Holley with Carter-Edelbrock as a close second. Skinner's are sorta neat with the damper oil, but I have seen them leak and catch on fire on an old Volvo.  I have never messed with down draft Webbers. They are works of art, but temperamental on street cars from all accounts. Autolite 2100/4100 are just easy to rebuild and work right. 

I  drive a 1990s Jeep with basically the same level of tech as a Fox Mustang. The fuel injection still seems to be working just fine. I see plenty of other cars from the late 80s through the 90s on the road still running OEM fuel injection with typically poor maintenance. The stuff from that time period was robust and really works well from most every manufacturer. 

 The fuel injection on Fox Mustangs is a known quantity and is pretty easy to work with.  For some reason, people seem to have a hang up surrounding OBDI, to me it is super simple. You check spark, timing, fuel pressure, etc almost like a carbureted car with the bonus of codes to help hone in on a bad sensor or the like. 

Most folks that do this conversion on this particular subset of automobiles are likely young and/ or out of funds by the time they put a fresh engine back in the car. I guess there are geezers that build Foxes with carburetors?  Or young guys offended by carburetor innuendo? 

Carburetors are cheap. On that point, I think we agree. 

These converted cars come up for less money than a well preserved and maintained fuel injected car. The workmanship is generally pretty shoddy with lots of qestionable parts thrown in for good measure and aimed at the quarter mile. I am generalizing here.  There are of course exceptions; cars prepped for road courses, high quality drag cars, and the like. I like Foxes so I look at them from time to time. 

In general folks that slap a carburetor on these are ill informed.  Does that sound better? The parts to do it right are all over the place. Ford built thousands of Explorers, Thunderbirds, SN95s, etc... There are tons ofof  aftermarket parts available new and second hand. The tech to do it right is all over the place on the net. 

I have to remember to add some smileys to my posts. Jest doesn't come across as it should some times. 

In 3 pages, only 2 people so far have named the issue that resonates with me regarding the old fuel injected 5.0, the intake manifold. I can maintain/repair a late 80s-early 90s efi system no problem, but..  

If you want to make power on an old 5.0 you really need to move the powerband up, and to move the powerband up you really need to change the intake manifold, and if you change the intake manifold by very much it necessitates a bunch of other changes, and (and this is the big one) upgraded intakes for the efi 5.0 score terribly on the value per dollar scale compared to a carb setup as they are very expensive. 

A lot of people have made a lot of valid points in this thread, but that's the one thing i would point to. 

It's not unhead of to get a machine shop to drill / weld injector bungs into a carb intake.  So that's always an option for keeping EFI.  

In reply to Vigo :

Good point.

1.Power increases come at RPM a production piece isn’t designed for. 

2. Those pieces are cheaper for carbs than for EFI. 

If it is any consolation to your factory EFI guys..The Minion just told me he is converting his  DD 5.0 swapped Ford Ranger to factory EFI from his vast collection fo Mustang spares. Seems that with a new job that is only 3 miles from home, and the engine never fully warming up,  the carb never fully gets with the game. This from a hardcore carb guy.

Pete

Here at Autobooks-Aerobooks in beautiful downtown Burbank, I see a large cross-section of car people from all over the world.  The carb-MFI-EFI argument is part of a larger discussion, that being whether electrons truly are the devil's spawn or not.  There are some people who will not deal with 12 volts of DC, never mind pulse width or any other parameter of EFI.  There is quite a large contingent who don't even own computers so the idea of a computerized anything is off the reservation.  These are people who can create sheet metal miracles or build beautiful engines.  Computers, electronics, electricity, and Ben Franklin with his key in the jar are too frightening to contemplate.

Before we get into stereotypes, I've seen plenty of older folks dive into computers and all their attendant glories and foibles.  I've personally witnessed 96-year-old Ed Iskendarian work his iPhone in a way that would make the average millennial jealous.  I've seen millennials for whom flatheads are the be-all and end-all.  The only generalization I might make may be people from other countries having an easier time with EFI because they're from The Land of $7.00 Gas and have dealt with it longer.

Some people hold their hard-earned knowledge more dear than others.  If you've spent 40 years finessing the finer points of jetting Holleys, you might wonder whether you can start from scratch and learn EFI.  If you can code, carburetors may be tiny mystical dungeons of pressure and vacuum.  I refuse to take sides because I see beauty in anything that mixes fuel and air. 

We sell carb books (Holley, Rochester, Carter/Edelbrock, Demon, SU, Solex, Weber, Mikuni).  We sell EFI books including books specifically dealing with carb/EFI conversions.  We also have the official Bosch EFI manuals as well.  Both carb and EFI books sell in equal measure.  There are some people in this world who want to expand their horizons (one way or the other) and some who are quite comfortable where they are.  The question is, which one are you?

KyAllroad (Jeremy) said:

Mine is EFI.  But entirely aftermarket.  The two piece intake manifold is weird and heavy, I can certainly see the appeal of a simple one piece with a 5 lb carb on top.

Thinking about "won't get 20+ mpg" comment.  600cfm Quadrajet on a spreadbore intake?  Seems like a nice compromise and in a light enough car, like a Fox Mustang...