3rd Gen 3S-GE swapping information thread, Use your old harness w 2/3gen swaps? Options

[H8TRAIN]

Wiring for Non-Turbo 3SGE swaps into Celica ST204 is undocumented. Strange but true. As of today, we have two 6gc members (KAOS and mi645) attempting the 3rd gen 3sge swap with no information on how to wire them.

I understand that the swaps have been done and are not difficult. I’m starting this thread in hopes that those with the experience can answer some questions about these swaps. The details of the wiring all follow from one primary question.

Question: Is it best to use a 5sfe harness to swap in the 2/3gen 3sge?

(Reminder: 3sge means non turbo or na. Without a ‘t’ in it. Not 3sgte. Normally aspirated.This thread is about the 3sge, NOT the BEAMS. That is not a typo. Atmo. Strictly vacuum. Sucker not blower.)

Following are the threads and posts that lead to this question.

This was posted on here by 99gt3sge

you can use your 3s harness, i did a swap for my friend using a 3rd gen 3sge non beams with his original 5sfe harness, i had to wire up two injectors, re-pin the dizzy, and re-pin the ecu plugs to run the ge ecu. and extended some of the tb plugs and wire in the acis solenoid. it's not as easy as wiring a honda but it's very doable.

From eazy2001x on mr2oc:

thats a Gen 2 celica engine, your better off using a 5S harness and modding it to work.

From user pimpm3 on mr2oc:
Sadly, the image of the wiring changes that he made seems to be lost on the internet. I tried waybackmachine. No luck.

I had a hard time finding the exact instructions on how to wire in a 2nd Gen 3sge into a 1991 Na car, so I made a chart that shows how I did it. I hope this helps.

The 26 Pin and 16 Pin connectors plug straight into the ECU from the engine harness, the only wiring I had to do was on the 22 Pin connector. I took the wires from the 14 Pin Body harness conector that and soldered them on as follows to the 22 Pin connector so it will fit in the 3sge ecu. I labeled the wires on each conector before I cut them and then all you have to do is match them up.

The car starts right up and runs great. You can hook STA from the 22 Pin Connector up to the starter relay if you like but I did not and the car starts fine with out it.

Open questions for anyone who knows:

Can the 5sfe celica wiring harness be used on a 3rd gen 3sge swap?
If so what changes must be made?
Is it simply an act of opening both ecus, looking at the printed diagrams, and matching them up?

The 3rd gen motor is supposedly the easiest to install but is the 2nd gen really any harder? Can not the 5sfe harness be modified slightly to run the 2nd gen engine and ecu? Again do the ecus need to be simply opened to reveal the key to matching a few pins?

Any info and thoughts appreciated! There are people out there right now trying to find this information! I know I have been asking around for weeks now!

[mi645]

its not so hard, im still curious how u managed to put a 3sgte clutch in there lol? if u have a spare 3sgte clutch maybe ill buy it to test if it works for the E56

[KAOS]

its not so hard, im still curious how u managed to put a 3sgte clutch in there lol? if u have a spare 3sgte clutch maybe ill buy it to test if it works for the E56

Now I have a spare pressure plate from a 5SFE and a friction disc from a 3SGTE (21 spline).

Anyone have any vacuum diagrams that they could throw up quick for me?

Still having issues with the swap.

Car starts, and idles great. Very smooth. But at 3k RPM it sputters, misfires and backfires.

Timing is good, 10 degrees with check connector bridged. Firing order correct - spark plug wires are all good. If you unplug each one of the wires it definitely changes the way the engine runs, so it is idling on all 4 cylinders. We had to take the timing belt off to deal with an oil leak, and it had the same misfire before and after. I triple checked the cam timing when the belt went back on.

No codes, even when I try the diagnostic mode. the CEL will flash when it misfires and hits this weird 2500 - 3000 RPM rev 'limit' but no codes are thrown. It will drive the wheels in 5th (car is on a hoist) so it runs fine under load, but has the same stumble/rev limit at 2500/3000.

Also loud backfiring out the exhaust, and the intake vacuum 'pulses' to atmospheric when it hits this rev limit. Plug gaps are fine but plugs are a little black. Seems like an ignition problem? Has new plugs, cap and rotor. Was going to try an igniter/coil assy from a known working ST205, also different plug wires. We also have another ECU to check with.

It runs beautifully right up until you hit this weird rev limit/misfire point. Starts right up, idles nice and smooth.

Any other ideas?

Going to try my other spark plug wires and my MR2 ECU on Monday.

Checked the TPS sensor, coil, and ignitor - all good. 90% of the parts are brand new.

I have a feeling about the wires, as I recall feeling a significant break in the #4 cable, but didn't really think anything of it when I installed it. I also want to check my vacuum lines because the ACIS is exhibiting an odd behaviour too ( I think )... and my fuel pressure VSV broke when putting the engine back into the bay. Snapped a nipple off in the hose.

This post has been edited by KAOS: Jul 24, 2014 - 9:43 PM