TBI on a Ford

[Dr.Danger]

Where might a guy find tech on that setup? I'd love some fuel injection but I'm way too cheap for one of the aftermarket jobs.

I'm going to start this thread to fill you in on what I did so we don't clutter up the intro thread too much, but I will have to fill in more later because I need to get off the internet and get back to work for a while. This will be more about what I personally did, as opposed to a general TBI guide. I also figure this may be able to help others decide if it's something they want to pursue or go another direction, as these systems are pretty long in the tooth. But there is still merit to them in my opinion, and especially from a learning perspective. Ford was always a few steps ahead of GM on the EFI front, and that left us carb guys without a lot of options for using our 4 barrel intake manifolds and D3VE and older 460 heads when they went to multiport.

In the meantime, GearheadEFI.com and Thirdgen.org are two great resources that I used a lot. Gearhead is for pretty much everything EFI in general, but has separate sections, and Thirdgen is all about TBI and TPI but has some solid info.

TBI works way better than a carb and CAN be cheap, but it can also get pretty expensive, and that money can be a good chunk of a throttle body "self tuning" EFI setup. I'm actually going to get a Sniper soon because I am going to be doing a more powerful build and I want more flow and will need more injector for it. If you are interested in a deal, we can talk about you possibly getting my setup when that happens. If not no worries, it'll eventually go on something else I own or build that it is more suited for.

If you do this, you'll have way more control over how your engine runs, and you won't have carburetor start up or wheeling issues anymore. I went TBI because I got sick of the carb flooding every time I so much as pointed the truck towards a hill. Even the 4x4 Holleys don't really work worth a shit compared to EFI. That said, there is performance potential but it is limited. A stock 454 TBI is 670 CFM which is good for a warmed up mild big block, but not a moderate one. For reference, I'm shooting for a moderate build of roughly 450 hp and I don't feel like this will be enough flow or fuel for it. They absolutely can be wicked up past stock though.

What are the details of your engine build? I assume it has a mechanical fuel pump? You will need an electric with the correct flow to run this but you won't need a whole lot else. You can even use the Duraspark distributor that is on your engine with the TBI controlling timing after locking it out. I'll cover that here too if you're interested with pics.

It's not terribly advanced compared to similar year Ford EFI, but it works alright and is also pretty dang simple. Think of it as a glorified electric carburetor that just happens to have timing control too.

Might be tomorrow before I fill in more.

 

[TrikeKid]

What are the details of your engine build? I assume it has a mechanical fuel pump? You will need an electric with the correct flow to run this but you won't need a whole lot else. You can even use the Duraspark distributor that is on your engine with the TBI controlling timing after locking it out. I'll cover that here too if you're interested with pics.

It's not terribly advanced compared to similar year Ford EFI, but it works alright and is also pretty dang simple. Think of it as a glorified electric carburetor that just happens to have timing control too.

Might be tomorrow before I fill in more.

My engine is mild as can be, stock 70's truck long block with an early timing set and a Performer intake. Already running a fuel cell and an inline electric pump so it'd be simple to swap for a higher pressure unit. I rarely rev the thing past 3500-4000, I just want consistent good manners that seem to be an issue with a carb and how often my truck sits for a few weeks at a time. I have a set of closed chamber heads on a shelf but I don't know if I'll ever get around to actually having them gone through and putting them on. Even then it'll be sub 400hp and low revving.

I'm fairly familiar with TBI in their native habitat and even though I'm a Ford guy I prefer em to the old EEC stuff, seems like they have less drivability issues and if they do they're quicker/easier to diagnose.

 

[speed bump]

Interested in seeing more on this. Right now I have an old Holley projection on a 360 FE. Since the truck is apart right now it's the best time to think about updating it.

 

[Dr.Danger]

Ok, looks like it's gonna rain for a bit so I have a little time between to add to this. I'm just going to go through components and list what I'm using. The tuning aspect I'll cover later, and there's a few options for that.

I'll start with throttle body: There's a few of them. There's a small block/V6 version(s?) and a two notable 454 versions, early and late.I am running the earlier version since it works better with my early ECM. These have different IACs from what I recall, but I believe they can easily be repinned to work.

People also overbore these to flow more. I have a 48mm bored over small block unit on the shelf that I picked up, but later got a 454 one, which is 50mm stock. If you had a lathe you could do the boring yourself and buy or fab some larger throttle blades, but I'm not sure how far they can go before they cut into the hollow bits. I'm sure that info is available on Thirdgen. They all have different injectors depending on application, but you can throw higher flow injectors in the smaller ones for increased performance, and dial up fuel pressure, which a lot of the small block crowd do. The biggest are 81 lb. hr, and what I'm using.

These can leak air into the unit after the throttle shaft wears out. Mine has a whistle on occasion in fact, but it has never been enough of a problem for me to care about. If you can you'll wanna put seals on the shaft when you go through one, or just say fuck it and run it. TBI is pretty hardy and not difficult to make run with less than ideal conditions. Until you get water in the computer, anyway. (Fun fact, TBI will start and run with the chip REMOVED from the ECM. This made it really fawking hard to diagnose a connection issue with my emulator cable one time.)

You need an adapter. You've got a 4 barrel manifold and these are 2 barrels, with 3 bolts holding them down. I am using an aftermarket adapter, but this is something I would definitely make using a transfer punch and a drill press. I have a Performer RPM manifold on mine and since that is a dual pattern (Quadrajet and normal square) pattern manifold, you could have leaks at the edges if you don't make it cover the hole. I did one thing to help balance it out, since dual plane divider. I cut out the middle of the two holes and made it sort of a figure 8 hole. The 4 barrel self tuning units have sometimes had issues with dual plane manifolds, and the solution is to cut down the center divider inside the manifold. I've essentially done that from the get go, but did it up higher in the adapter because easy.

There is a stock aluminum 454 adapter out there. I was happy as hell that I had found it WITH the 454 throttle body, until I found that It did not work on my manifold because it's different enough from the stock 454 iron manifold, that it had open slits on the sides to let air through. It may work on yours but so does a flat plate with holes in it. These are not my pics but they're the same thing I found on ebay.

Dual pattern 4 barrel style:

Stock 454 adapter, notice how the center is connected? That's what I did to the above adapter. The fittings in the front, rear, and sides are for water. These were heated from the factory with coolant, which nobody in Texas or other warm states gives a hoot about, but you might.

 

[Dr.Danger]

Interested in seeing more on this. Right now I have an old Holley projection on a 360 FE. Since the truck is apart right now it's the best time to think about updating it.

I had several Projection setups come past me when I was researching this setup and I'm glad I didn't buy any of them. Lots of terrible experiences documented with those units, but what do you expect for a Mopar style TBI unit with dials on the side of the ECM box for "tuning".

If you're crafty with Megasquirt/Microsquirt you can easily control one with that, and I bet you could use a TBI ECM to control it too as long as the TBI ECM's drivers are capable of firing the injectors in them. I have seen a dual throttle body TBI setup once. I believe it was on the Texas Rose truck from over 10 years ago (top truck challenge) that one of the guy's in Texas A&M Offroad had. It had some modifications done to the drivers IIRC but it is in fact possible to have a dual throttle body setup.

 

[Dr.Danger]

You are going to need a return line. TBI has an integral fuel pressure regulator in it. This is going to need to be dialed up in most cases so you aren't using a retarded wide injector pulse width (time the injector stays open during a squirt). Obviously more pressure means more fuel goes through in the same amount of time.

I was shooting for 17, and tried a bit of a hail mary on this. I wanted to save money not buying a regulator, and I didn't feel like making one, so I shimmed the spring in the FPR (fuel pressure regulator) with pennies or washers or something and got exactly the 17 PSI I wanted on the first try. The adjustable regulators add a screw so this can be dialed up and down, and just like a Saginaw power steering pump, you're just increasing the amount of pressure it takes to push the spring down and open the diaphragm and let fuel out.

Thank you for your picture gmtruckclub.

Adjustable you can pay too much money for:


Homemade:




There is a handy calculator out there that will tell you roughly what you're going to need. I don't have it on this computer or I'd upload it, but it's easy to find with a simple search.


Since we're talking about fuel pressure, I'm going to skip to the ass end of the system and cover fuel pumps. The stock TBI controls the fuel pump with a weird looking fat relay. You don't necessarily need to use it if you don't want. A factory Ford F-250 from 1983 has two square relays up between the brake booster and fender. One of them controls the fuel pump going out back. Since it was a factory Holley carb equipped truck but had electric in tank pumps, all it did was turn on the selected pump when the key was on. This doesn't bother me as I don't leave the truck key on unless it's going to be running.

You don't have that seeing as you had a mechanical fuel pump, but that might help someone who does. I think 1983 was the first year of this, so keep the GM relay and reuse it to save money, or use a simple 4 or 5 pin square relay if you're like me and keep cheap chinesium ones on hand for various projects. They are stupid cheap on ebay.


Stock, TBI has been known to run as low as 7 psi. We're not getting much out of her like that. So, we need a pump that's better than carburetor pressure but not quite Walbro 255 or Bosch 044 territory. You're gonna want to use something that is a lot closer to your targeted fuel pressure.

I went to the parts store and dug through the book to find an in tank pump that supplied what I needed, which of all things ended up being a the in tank pump from a 1989 Ford Tempo. It flowed enough for my needs and put out 40 psi max. Perfect.

Not sure what frame rail pumps would work for this and be lower pressure, but I wanna say late 80s F-150s had a frame mounted fuel pump, and this thing is copied as an aftermarket pump by the likes of MSD. Again though, you don't need an 80 psi pump, and my theory is that excessive pressure is gonna long dick her diaphragm. When those pop you get fuel all over the back of the engine and some of it pours down the intake making it run like shit. Also, vehicle fires are bad, especially where liquid fuel is involved and fed steadily by an electric pump, so I'd try my hardest to avoid that.



Last thing for this post, and it applies to the throttle body again.

We need an air cleaner of course. TBI has the injectors up above the throttle blades and main body of the TBI, and they can get in the way of flow, but that's not our real issue when looking for near stock performance. We quite simply can't fit an air cleaner up top without a way to raise it up. You could use a simple cheap plastic 1" round riser to bring the rusty 14" saucer you call an air cleaner lid above the tops of the squirters, but it sits so close to the injectors that it cuts air flow down really bad.

To fix this, you're going to need a state of the art advanced piece of hardware, the likes of which has only been used in rocketry, advanced thermodynamics and the highest tier of motorsports design.

The salad bowl.

Yep, it's actually a salad bowl. You could pay Jeg's $42.99+ tax for this, but I opted to buy an actual bowl and cut out the bottom and glued some emissions hose around the edges to create a seal. The salad bowl allows enough air to flow down from the air cleaner into the unit.

So champions, stop by your local Ross, keep your head down so your friend's wife doesn't see you shopping there too, and grab a bowl of adequate size and hurry back to your safe space (the shop).

Here's what the salad bowl mod is supposed to look like: