Good Place to start

toddi01 · Post by **toddi01** » Thu Feb 16, 2012 8:36 pm

I have a Toyota 20R engine running the hydraulic pump in a Bobcat excavator. I would like to replace the asian carb with a GM TBI injection. I do not need closed loop and wont have a VSS. I have a bin frome someone that got a 20R running with a 7747 ecm and I am thinking this is a good place to start. Is there any easier place to start with this?

EagleMark · Post by **EagleMark** » Thu Feb 16, 2012 10:01 pm

Well all the wiring diagrams you need are here:
http://www.gearhead-efi.com/Fuel-Inject ... rmation-42

There's a write up for doing EFI conversions started here:
http://www.gearhead-efi.com/gm-ecm-pcm- ... rsion.html

You'll need a newer EFI distributor and the pickup sensor in it will fire the EST module mounted externally on aluminum heat sink plate.

Will need an inline fuel pump for TBI and a return line. Have some fuel pump numbers at above link.

O2 sensor will help and it's to easy to install. You can go without VSS.

I have a TBI adapter for 2 barrel Toyota here in my shop a machinist made and we are doing his truck, PM me your number if you need one and I will tell him to call you. I don't know of any others available?

toddi01 · Post by **toddi01** » Fri Feb 17, 2012 7:30 am

Thanks for the great links
I am planing on using the harness from the vehical the ECM comes from. Finding one that old could be a challenge but should be possible.

The ignition is running on a GM 4 pin ignition modual now so I should just have to swap the modual for the FI modual and unplug the vacume advance hose

There is a fuel pump with return so an external mount pump should be able to replace it I have seen some posts that Ford used that type of pump on Rangers and Thunderbirds so will look for one when i am at the yard

The oxegen sensor can be added later but is not a priority

I am wondering if there is another TBI 4cyl ECM and BIN to start with that may work out better and if anywone has any hints on tuning for this application as the load on the engine will change when digging etc but the throttle position wont as it is set with a lever depending on the hydralic speed required. One featurde I would like to add is rad fan control. The rad fan is wired to the ignition power now works but could be done better

EagleMark · Post by **EagleMark** » Fri Feb 17, 2012 9:27 am

Use TunerPro and tune the bin. It is the only way to get a correct bin for this application. You will not be able to tune without narrow band O2 sensor hooked to ECM or wideband O2 sensor (way more expensive) to know how to adjust fueling.

No electric fan controls in 1227747. But there are aftermarket kits to turn fan on vai thermastat in radiator and relays. For this piece of equiptment and proper thermastat leaving fan on all the time will not hurt.