Swap to EFI

[Yotayak]

I want to do an efi swap on my 81 p/u, 3 in suspension, 33 inch, 4.88 gears. Does any one know of a site/person that could give instructions? I'm a newbie.

[blutoy]

I did a swap on my '85, but thats a whole lot easier than it would be swapping to an older truck. I know Chris G. did it to an early style truck, I read his write-up and it sounded like a pain in the ass. He basically had two wiring harnesses for his truck, one controlled the lights and accesories, the other for the engine. This probably doesn't help you much but from what I've read its a pain in the ass and probably not something a newbie should try.

[Spider]

I put a 85 efi setup in my 81 yota 4x4. I started out with all the necesary parts, ecu, complete wiring harness, sensors, throttle body, exhaust manifold, intake, injectors yadda yadda yadda. I ripped every single wire from the 81 wiring harness out of the truck, except for the tail lights and seat belt reminder. :) I installed the 85 harness into the truck. After installing the wiring harness i took my trusty haynes manual (might upgrade to a toyota manual one of these days) converted all the dash wiring plugs on the new harness to work with the 81's plugs. after I converted all the plugs, I just had plug them into the appropriate spots and everything worked just fine. Head lights, brake lights, running lights, blinkers, wipers, and believe it or not I now have a horn. I didn't before!

As far as the motor was concerned I must not have gotten the whole harness because I didn't have the injector resistor hooked up so it didn't want to run at first. after I got some technical help and plugged that in, It fired right up.

I think its idling a bit to hi right now, and it is popping alot on idle. I'm kind of hoping I can put a new exhaust gasket on and turn the idle down a bit, maybe that will calm it down.

If anyone has had the same popping noises go on after their conversion please let me know how you fixed it!

I'm not sure if the alternators will cross either, I went ahead and put a chevy on mine.

Don't forget to get the efi gas tank and sending units, yours won't work. I ended up mounting the tank in the back of the bed, because the efi tank is a little bigger. As for the efi fuel line fittings, go to your junk yard and try to find them of a efi truck or early celica they are the same (At least they worked for me). After I had the fittings , I just hose barbed them to some rubber efi fuel line and nailed em' down with hose clamps. They havent blown off yet. dont forget the return line if you mount it in the bed. I used 10 feet of 3/8" for the fuel line and 10 feet of 1/4" for the return. If you get the fuel line fittings off of another rig, don't forget to leave enough hose on there to plug the hose barbs in. the 3/8" fittings into the yota fuel lines is like trying to shove a b-52 into a cessna, but it will fit.

Don't forget plenty of beer and copenhagen, your gonna need it.

If I had to do it again? I would either put in a v8 with a turbo 350 and a chevy transfer case. All you would have to do is convert the drive lines and get a new radiator and a few other things and do a little trimming here and there...

piss on it, just throw a buick in there!

Ed

[MattMan]

I've done it twice. The first one I did would be similar to what you would most likely do, it was an 84 Celica GT into an 84 carbed pickup. I bought the whole car for $300 and swapped the whole engine, and cut what I needed from the harness. I spliced the EFI stuff into the truck's harness in maybe a half a dozen places, and ran a seperate fused 15A relay for the EFI. The wires to the air flow meter had to be lengthened to reach for the truck, maybe 3' or so. I just pulled more wires from the celica that matched and lengthened where needed. The 83 and 84 celica EFI is a little different than the 85-88 truck EFI, it's got vacuum advance on the distributor, and therefor no knock sensor on the block. Overall I was very pleased with the results...

If you really understand how EFI works, you can read wiring diagrams, you can solder, plenty of time, and you have a patient attitude, it's not really a big deal. If you don't know wiring and EFI pretty well, I wouldn't attempt it without some help... I had none when I did mine. If you're mixing and matching parts to come up with a setup, keep in mind the different generations and subtle differences between years. At the very least a Haynes manual is needed for your truck and for the donor vehicle. Preferably a FSM.

[Chris Geiger]

Originally posted by blutoy
I did a swap on my '85, but thats a whole lot easier than it would be swapping to an older truck. I know Chris G. did it to an early style truck, I read his write-up and it sounded like a pain in the ass. He basically had two wiring harnesses for his truck, one controlled the lights and accesories, the other for the engine. This probably doesn't help you much but from what I've read its a pain in the ass and probably not something a newbie should try.

The pain in the ass part was removing and replacing the stock harness. I pulled it out thinking I was going to run everything off the new harness. After finding that non of the connectors were going to work I ended up putting the entire stock harness back into the truck and hooking every thing back up like it was. So basicly I had worked on it for a coule days but was back to square one.

The second attempt worked much better. This time I used the new harness to just run the motor. I made some minor changes in the new harness just to get it working. For testing I did not pull the new harness into place, I just sort of draped it over the truck and fenders. Once it ran, I started simplifying the new harness. Most of the wires in the new harness were removed only leaving the ones needed for the motor and it's computer. Once simplified the new harness was wrapped in tape and then installed. Only a few wires needed to be connected between the two harnesses, ign, start, 12V DC and ground. Other than these connections the two harnesses were seprate. Later when I converted to a full buggy, I removed the the body and the body harness. I just kept the simplified engines harness.

I would not even consider doing this without the factory service manual. It was a life saver.

[Spider]

I've had a pretty positive experience so far with my swap but it's just the little pain in the ass things that are getting me now. Once I get the 4wd toyota done, I'm almost thinking about doing the (cough) 2wd!

Ed