convert 3A to EFI

Pegger · Post by **Pegger** » Wed Jan 05, 2005 6:18 am

Hey now that looks pretty good. A little pricey. And do they make a throttle body to fit on our little engine?

I'll do some research when I have a bit more time.

Thanks for the tip!

Guy

Jerry · Post by **Jerry** » Wed Jan 05, 2005 3:05 pm

FWIW, <a href='http://www.turbocity.com/' target='_blank'>Turbo City</a> has been building FI conversions for years. Might be a good resource for someone...

Or, if you're really adventurous:

<a href='http://home.earthlink.net/~jcgebhart/msindex.html' target='_blank'>MegaSquirt</a>

or

<a href='http://www.diy-efi.org/diy_efi.html' target='_blank'>DIY EFI</a>

Jerry

Adelard of Bath · Post by **Adelard of Bath** » Thu Jan 06, 2005 12:14 pm

Can I just throw in my two cents here, disregard if you like.

I am the first person to be all for EFI over carb cuz from my engineer's point of view, carbs = "so nineteenth century"

That said, a "throttle body injection" such as the Weber one linked to earlier, is just a FI version of a carburetor...they are certainly a step above carbs in that you don't have floats and bowls and jets and diaphragms and vac lines everywhere, a million things to go wrong...but there will still be problems like "manifold wetting" when you open the throttle and the opposite effect when it closes, the saturation of the mixture...Those can be compensated for pretty well by the computer though.

Four point injection is where it's at, though; my volvo has it from the 70s, its awesome. and there's not even a computer, just this metal plate that "opens" as more or less air flows through it, and that is directly connected to a pressure valve that increases or reduces the fuel pressure to the FOUR injectors, which then spray more or less fuel, dependant upon the pressure. it works nicely all the time, la la la

Ya know I wonder if I was crazy enough, given the super simpleness of that system...hmm i wonder if I could go to junkyard and get one...heh put it on the toyota...nah that would be crazy. but the engines aren't THAT much different in size, there would be much custom intake modification to make it fit on the tercel's head....oh then I would have to lay my hands on a 90psi fuel pump or whatever it runs.

Nah I think I will just leave it carb for now

Jerry · Post by **Jerry** » Thu Jan 06, 2005 12:29 pm

Adelard is right - multiport fuel injection (where the injectors are in the intake runners, pointing directly at the intake valves) will provide more power, better efficiency and eliminates the manifold wetting.

An added plus is a system that measures the amount of air coming into the engine (via a mass air flow meter), versus one that has is speed density. A mass air system, generally speaking, will adapt better to any sort of engine modifications (headers, exhaust, camshaft, etc.)

Does anybody know of any engines that were MFI, in the 1.5 liter range, and were pre-obd II (which, from what I understand, makes it much more difficult (if not impossible) to transplant into an older vehicle)? Oh, you'd want it to work in "closed loop" mode as well, using the O2 sensor in the exhaust manifold to adjust air / fuel ratio.

I'm not a fuel injection expert, but have done research in the past. My plan was to swap a late 80's - early 90's Mustang motor into my Bronco... That was, before I decided to sell it.

Pegger · Post by **Pegger** » Thu Jan 06, 2005 7:41 pm

I am also quit fond of multi point fuel injection systems. That is definitely what I would prefer to do to my 3A.

My idea was to transplant just the head from an EFI toyota, modify exhaust and I'm in... I guess it's not that easy...

I'm not familiar enough with the Toyota engines to know which heads might fit the 3A.

Can anyone give us more clarity on the interchangability of the 4A head onto a 3A engine? Will it fit? Same coolant and oil passages? I don't have the know how to figure it out...

Thanks, Guy

3A-C Power · Post by **3A-C Power** » Thu Jan 06, 2005 8:50 pm

There's the 4A-FE and the 4A-GE heads. Both should fit as the 3A-C uses the same head as the 4A-C which uses the same block (besides some minor details) as those engines. The 4A-FE is cheap and easy to find at any junkyard. Difficulties with it would be making the high intanke manifold fit and making the distributor that sticks out the end of the head fit. I haven't tried or measured, so it may be easier than I think. The 4A-GE 16 valve head will fit the Tercel's engine compartment (with modifications to the hood) and the intake points the right way and the distributor isn't an issue. That combination would give you a 3A-GE without the stronger rods and block reinforcement that the 4A-GE had to handle the extra power. In each case you would be using the wrong pistons with valve cutouts to mach the 8 valve head and might face interference issues. So the heads will bolt on, but just like an engine swap, even if it bolts on the rest of the details make it hard.

Pegger · Post by **Pegger** » Thu Jan 06, 2005 9:22 pm

Ok, more questions... I appreciate everyone's input, thanks...

I've never seen the top of the pistons for any Toyota engine. Does the 3A piston have cutouts for valve clearance? does the 4A have cutouts? Wouldn't that automatically eliminate my idea?

Having said that, has Toyota ever made a SOHC EFI engine (same 8 valve setup as the 3A) in the "A" series engine? I personally don't think so, but this is not my area of expertise.

So the 4A (FE or GE) are 1.5L or 1.6L? If it's 1.6L, would the different displacement make the air/fuel ratio too rich?

What cars will I find the 4A-FE in? Will the distributor on those be AFT of the engine?

Ultimately what I'd like to do is either prove it CAN be done before spending green stuff $$$ OR eliminate the idea with reasonable proof it CAN NOT be done.

If we can prove it CAN be done I will not be afraid of spending $ to do it, start a donor car search ETC.

I hope that with everyone's help we just might figure it out. And pave the way for others hopefully.

Optimistically, Guy

tercel4wdrules · Post by **tercel4wdrules** » Thu Jan 06, 2005 11:34 pm

You will find a 4A-FE in Toyota Corollas '88+ and some Celicas I believe. I know you can also find a 4A-FE in a Geo Prizm as well if I'm not wrong. Sometimes you can find these engines for $250-300 if you're lucky. 20v Tercel knows of someone bolting in a 4A-G block to a 3A head to keep it carb, but you don't want carb. That would be funny if you could make a 3A-FE.

I wonder if the 7A-FE head would fit. Does anyone know the difference between the 4A-FE and the 7A-FE? I believe the 4A-GEs/FEs are 1.6L. Well the closest engine I can think of that is SOHC EFI I think is the 3E-E with 12 valves, but the engine is terrible. I might be wrong though and that is an "E" series engine. I suggest you look in car-part.com for a donor engine for your mission, should you decide to accept it.

Pegger · Post by **Pegger** » Sat Jan 08, 2005 12:40 pm

I'm concerned that a head with more than 8 valves will cause interference with the pistons.

So I had a thought, please share your input...

What if I kept the 3A head and bolted on the 3E-E intake with it's EFI? Do you think it's possible? Would it fit on the "same side" intake and exhaust on the 3A head? It's seems like a far fetch. I have not measured or even looked at the space available.

Any one have detail pics of that side of the 3A head with the manifoids off?

Guy

3A-C Power · Post by **3A-C Power** » Sat Jan 08, 2005 2:55 pm

The 3E is totally different and pretty useless when it comes to 3A engine swaps. One member from France told us that they had fuel injected 8 valve engines in the older Corolla (they did use 4A engines) but I have not found any information on that including in the European parts catalog. The only fuel injectors are for the diesel. If you want a multipoint injection without having to change the whole engine, it would probably be easier to put injectors in the stock manifold and use the carb as a throttle body. You would have to drill some holes in the intake and weld on bosses for fuel injectors which could be cut off of the manifold of an EFI engine. There are aluminum brazing rods that you can use with a torch or you could even possibly get away with JB-Weld epoxy. To make it work with the 3A-C's lack of electronic ignition, you could use Megasquirt with the O2 sensor, MAP sensor or AFM, and engine and air temp sensors from some other engine custom mounted in.

Pegger · Post by **Pegger** » Sat Jan 08, 2005 3:12 pm

I know from experience that the 3E is not a good engine. And I certainly would never entertain the idea of putting it in the wagon, or anything else for that matter.

My question was simply would the 3E-E's intake manifold match up and have enough space to be fitted on the 3A head?

Guy

P.S. My wagon is my daily driver so for me to rip it a apart for a "let's try this" is a little scary. I wish I had the components we're talking about and see if they fit together, like LEGO's! LOL...

3A-C Power · Post by **3A-C Power** » Sun Jan 09, 2005 2:18 pm

I suspect the intake ports are completely different and the 3E intake would interfere with the 3A exhaust manifold.

Pegger · Post by **Pegger** » Sun Jan 09, 2005 5:18 pm

I think that too... I'm just hoping it might... Maybe a little custom work, who knows.

WHen spring comes around I might go play LEGO at the scrap yard...

Guy

3A-C Power · Post by **3A-C Power** » Sun Jan 09, 2005 7:16 pm

I do that at wreckers. In fact when I go there that's mostly all I do, besides getting the part I came for if it exists. Sometimes I only say I need a certain thing to get into the yard. Most wreckers' attitude towards hobbyists like me is basically telling me to 'F' off, and that they don't have the part I need.

Pegger · Post by **Pegger** » Sun Jan 09, 2005 10:21 pm

If you get a chance before I do, would you check it out?

Winter here in the 'Peg is way too cold to play in the scrap yard...

Guy