Project 20RE: Junkyard fuel injection with TBI

YotaJosh

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Project 20RE - Junkyard injection with TBI

What: inject a Toyota 20R 4 cylinder motor with GM Throttle Body Injection (TBI) as cheaply as possible
Why: 22RE's don't grow on trees around here, and usually need a rebuild before dropping in the engine bay. Plus I like to try new things, and I have a good running motor that I don't want to throw away.

Ever since I started wheeling my Toyota, I've realized that carbs suck off road. Granted, the factory Aisin carbs are better than most, I still had issues. The Land Cruiser crowd has been adapting the GM TBI system to the F and 2F motors for years, so I knew it was possible to convert this system to run just about anything.

To begin this project, I started searching around for companies that sold kits or parts, and found a few, but the prices were out of my budget ($1000 or more sometimes). I figured I could do better. I then started researching the TBI system in general, and found that it has a strong following in many denominations of the automobile world. One such group is the IH crowd, or "binders" as they refer to themselves as. This lead me to Binder Planet, and all the wonderful tech that is contained in the "Injection Tech" section of their forum. A man by the name of Bill Hamilton has his act together! By soaking up all the info there, I was prepared to begin collecting parts for my project.

So, here's the breakdown of my system, and the source/price of each component (* items came from junkyard):

  • TBI unit from a 4.3l Chevy V6* - $25
  • 7747 ECM (computer) from a 5.7l Chevy C1500* - $25
  • Wiring harness from a 5.7l Chevy C1500* - $25
  • Ignition coil from 5.7l Chevy C1500* - $8.99
  • 22RE Distributor* - $20
  • Dodge Durango air cleaner housing and duct* - $10.99
  • FJ80 throttle cable* - $10.99
  • MAP,ESC,Ignition Module* - Free thanks to cargo pants. :D
  • 3/4" x 6" x 12" aluminum plate (for adapter) - $17
  • O2 Sensor - Bosch 13077 - $44.99
  • Non-fouler 42002 - to make O2 bung with - $4.29
  • Spectre 3" cone air filter - $20
  • 3" exhaust pipe coupler - to attach air filter to duct - $2.99
  • Fuel pump - Airtex E8094 - $112.99
  • Moates AutoProm APU1 burner/emulator/ALDL logger - $330
  • Moates G2 memory adapter - $30
  • Moates S2 28-pin ZIF socket - $10
  • Various nuts/bolts/connectors/etc - $20


So far my total is $718.23. So far I'm less than a standard propane conversion, and less than a 22RE core and rebuild. :D

The big hit in the project was the AutoProm programmer at $330. Take that out of my costs (plus the ZIF socket), and it's only $378.23. :eek: I feel that since nobody had a BIN file for my ECM to run a 20R, the programmer was a good investment.

I'm still tuning the system, but so far, I feel it was money well spent. Off road performance is awesome, and the engine really likes the TBI.
 

YotaJosh

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Here's the overall shot of the system. You can see the "Cold Air Intake" system I came up with. A regular round 14" aircleaner would have worked too, but I was afraid of hood clearance issues.
The parts came from a Dodge Durango. I had to dremel out some of the internal parts to get it to clear the injectors.
IMG_5966.JPG


Wiring harness. Yes, I used black tape to wrap it, and I wish I hadn't. I didn't cut or splice any of the factory GM harness. That's why it seems long in places, and doubled over.
IMG_5961.JPG


Where harness goes through firewall to ECM. 2" hole saw works nicely. Grommet is a Toyota firewall grommet from the junkyard.
IMG_5960.JPG


Fuel pump relay and main system relay. I reused the FP relay that came with the harness, and found a off road light relay for the system relay. The red wire with the spade connectors leads back to the fuse box and ties into the ENGINE fuse.
IMG_5962.JPG


4.3l Throttle body, Coolant temp sensor, and homemade adapter plate. I need to clean the TB a bit, but internally it's clean, so I didn't worry about it. The CTS screwed right into the Toyota intake. The adapter plate is made from 3/4" thick aluminum. I matched up the gaskets for both the 20R carb and the TBI unit and traced out the holes. Then I used a 1 3/4 hole saw to make the center bores, a wood blade on a sawzall to rough out the inner taper (since the TBI bores are bigger than the intake bores) and smoothed it all out with a die grinder.
IMG_5963.JPG


ESC, Ignition Module. I decided to keep the knock sensor (mounted on the block in the water drain under the header), so I needed the ESC module. Also, the GM ignition module needed a heat sink, hence the small aluminum plate behind it. The 22RE distributor connects to the ignition module in a specfic way: distributor red wire -> P terminal on module. distributor white wire -> N terminal on module. If you get them backwards, you won't get a proper signal to the ECM and it will run like poop.
IMG_5967.JPG


GM coil, in stock mounting holes. Stock bracket lined up with the existing holes in the fender.
IMG_5968.JPG


22RE distributor, no vacuum advance. You could modify a 20R or 22R distributor to remove the vacuum advance parts, but I figured this was easier.
IMG_5969.JPG


Throttle cable connection. I found a very long FJ80 throttle cable in the junk yard that allowed me to put the mounting anywhere I wanted. I ended up having to cut a large part of the TBI linkage off to fit the intake near the Toyota EGR port. I rewelded some of the cut parts back to the top of the linkage so the cable could be used in a stock fashion.
IMG_5970.JPG


O2 sensor. I'm using a 3 wire heated Bosch 13077 sensor. The bung is a 18mm spark plug non-fouler cut in half and welded in place.
IMG_5971.JPG


Fuel pump. Airtex E8094. Puts out 17-20 PSI and 50 GPH. Perfect for TBI setups. It's a pricey one though.
IMG_5973.JPG


ECM, ALDL, check engine light. THere isn't any space under the dash of the first gen trucks, and I wasn't going to gut anything to make space, so I mounted the computer on the kick panel. You can see the chip and ZIF socket sticking out there. I plan on removing the ZIF and the cover will fit again. Also, I mounted my ALDL connector close to the ECM, and the check engine light is a Radio Shack LED mounted on the ALDL connector. By doing this I kept all the wiring in one area.
IMG_5958.JPG


AutoProm from Moates.net. This lets me burn chips, log data from the ALDL connector, and also it can emulate chips on the fly from the laptop, so I don't have to "burn chips, reset ecm, test drive, repeat". Just make the changes and start the motor.
IMG_5957.JPG


There isn't an off the shelf ECM that will run the 20R good, so I started with a 7747 ARHT bin, and changed the # of cylinders to 4 and the BPW to 138. This got it in the ballpark, but it's still running a tad rich. Using programs like WinALDL and TunerPro, I can log data and change the code to dial it in.

And finally, here's some links I found useful during my conversion...
2F TBI Conversion
Another 2F TBI Conversion
TBI FAQ on Binder Planet
IH8Mud user adding TBI to a carbed 350
Moates AutoProm
Great PROM/BIN programming info at ThirdGen.org
Lots of great tech on the 1227747 ECM
How to install the 24-pin to 28-pin adapter in the ECM
Great info on tuning the ECM at FullSizeChevy.com
 
Joined
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6259 Offenhauser 2.4 Toyota dual port intake manifold
:grinpimp:

I think this is the intake you are speaking of,
I gotta a big hook up in a junkyard up north, to clarify here be my questions;


TBI unit from a 4.3l Chevy V6* - $25
7747 ECM (computer) from a 5.7l Chevy C1500* - $25
Wiring harness from a 5.7l Chevy C1500* - $25
Ignition coil from 5.7l Chevy C1500* - $8.99

Years on the above?

22RE Distributor* - $20

Dodge Durango air cleaner housing and duct* - $10.99
year?

FJ80 throttle cable* - $10.99
you found this in a junkyard? you got good junkyards.

MAP,ESC,Ignition Module* - Free thanks to cargo pants.
Alright, eliminate my ignorance. MAP? ESC (elec stability control??)?
3/4" x 6" x 12" aluminum plate (for adapter) - $17
Eliminate via offenhauser adapter

O2 Sensor - Bosch 13077 - $44.99
Non-fouler 42002 - to make O2 bung with - $4.29
Spectre 3" cone air filter - $20
3" exhaust pipe coupler - to attach air filter to duct - $2.99
Fuel pump - Airtex E8094 - $112.99
Oreillys/Napa/Autozone parts.

Moates AutoProm APU1 burner/emulator/ALDL logger - $330
Moates G2 memory adapter - $30
Moates S2 28-pin ZIF socket - $10
Ehh... Program mine for me?
Various nuts/bolts/connectors/etc - $20
Oreillys/Napa/Autozone

I may not start this until winter break, but more time to do it right... right?
 

YotaJosh

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6259 Offenhauser 2.4 Toyota dual port intake manifold
:grinpimp:

Too expensive. :hillbilly:

I think this is the intake you are speaking of,
I gotta a big hook up in a junkyard up north, to clarify here be my questions;


TBI unit from a 4.3l Chevy V6* - $25 Any Year as long as it's a two barrel TBI unit. Look for a 2.8 though, as that's the route I'm trying next. 4.3 bores are too big (I'm figuring out)

7747 ECM (computer) from a 5.7l Chevy C1500* - $25
Wiring harness from a 5.7l Chevy C1500* - $25
Ignition coil from 5.7l Chevy C1500* - $8.99

Years on the above?

All from a 1991 manual trans full size

22RE Distributor* - $20

Dodge Durango air cleaner housing and duct* - $10.99
year?

First gen Durango. Not sure on year. Dakota's had the same type of air cleaner. I was walking the yard and it just jumped out at me so I bought it.

FJ80 throttle cable* - $10.99
you found this in a junkyard? you got good junkyards.

Cash 4 Clunkers!! We stripped that cruiser. :grinpimp:

MAP,ESC,Ignition Module* - Free thanks to cargo pants.
Alright, eliminate my ignorance. MAP? ESC (elec stability control??)?

MAP = manifold absolute pressure, aka vacuum sensor
ESC = electronic spark control. retards timing using a knock sensor


3/4" x 6" x 12" aluminum plate (for adapter) - $17
Eliminate via offenhauser adapter

If you have a 22R, the adapter from Affordable Fuel Injection is cheaper ($115 from AFI) They don't make one for a 20R, and I didn't want to stack adapters with an LCE 20R/22R carb adapter.

O2 Sensor - Bosch 13077 - $44.99
Non-fouler 42002 - to make O2 bung with - $4.29
Spectre 3" cone air filter - $20
3" exhaust pipe coupler - to attach air filter to duct - $2.99
Fuel pump - Airtex E8094 - $112.99
Oreillys/Napa/Autozone parts.

Moates AutoProm APU1 burner/emulator/ALDL logger - $330
Moates G2 memory adapter - $30
Moates S2 28-pin ZIF socket - $10
Ehh... Program mine for me?

The base programming I have now will run your truck well. You will still need the memory adapter at least ($30), as the chips I can burn don't fit the factory PROM socket in the ECM. The ZIF makes it nice when you are pulling chips 3 dozen times a day tuning, but it's not required.

You will want your own ALDL cable and a laptop (any old one will do) if you ever want to log data to send to people that can burn chips (such as me).

Various nuts/bolts/connectors/etc - $20
Oreillys/Napa/Autozone

I may not start this until winter break, but more time to do it right... right?

Right, or was it left. :hmm:

Answers in blue. :)
 

YotaJosh

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Thanks, so this uses OBDI?

Ill do the AFI adapter. 2.8 Throttle body, im assuming, will mount to that? I've got a TBI 4.3, missing the intake/TBI... Go figure...

Yes, OBD1, and the 2 barrel TBI units are the same bolt pattern from 2.8 to the 454.
 

YotaJosh

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Did you have to install a knock sensor? I'll think of some more questions... Im gonna be in LR around the 19th for the Jeff Dunham show, wanna show off your rig?

Knock sensor isn't 100% necessary, but it was easier to leave it in the system than to remove it.

I'll be around on the 19th. It's a regular ol' Monday workday.
 

YotaJosh

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So you drilled and tapped the block to add the knock sensor? Where at?

Nope. There's a water drain on the driver side of the block right under the #3/#4 exhaust ports. With the right adapter (from the Home Depot plumbing dept. :hillbilly:) the GM knock sensor screws right in there.

Putting the knock sensor in coolant is the preferred way. Putting the knock sensor in dead air (say in a fuel pump blockoff plate) will cause false readings, which will lead to timing problems.
 
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Alright, so...

Heres what i got already...

2.8L TBI - 35$
22RE Dist. - 15$
AFI Adapter (ordered) - 130$
ECM 5.7L Manual 1500 - 35$

Gotta find a wiring harness, and hope to jack all the sensors from that truck.
 

YotaJosh

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So, will the harness from the 2.8L vehicle work? Or will that specific ecu not work on everywiring harness?

The 2.8 harness will probably work, but I'm not 100% sure. You might have issues with the pinouts where the harness plugs into the ECM as some were different.

I'd play safe and get one from a 4.3 Blazer/Astro or a 5.7 Truck.
 
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Playing it safe and picking up the harness from 4.3, as well as the sensors and im gonna grab the intake/TBI for my own 4.3 when/if i do that swap. As long as the price is right...
 

YotaJosh

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How is the miles per gal. ?

Meh, don't keep track of it too closely. It gets as good or maybe a tiny bit better than the stock carb did. 75% of the time the truck is offroad, and I don't have the system exactly tuned for the best economy either.
 

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