Using a '93 3SGTE ECU on a '91 3SGTE Engine and Harness Options

[Dr_Tweak]

Some weeks back I had a customer doing a 3SGTE swap into a '91 Celica that I did a wiring conversion for. After he got it back and installed, I asked him for the part number on his ECU since I've seen many situations where the importers send the wrong ECU for the year of the harness. Sure enough, he had a '91 Harness but a '93 ECU. I advised him to get a '91 ECU, but he was having a hard time locating one.

About the same time, I started gathering parts and doing research for making jumper harnesses for various Toyota applications. I located the supplier for the female ECU plugs for a few different Toyota harnesses. When I got one in that matched the 3SGTE harnesses, I though, why not make a jumper harness that goes from a '91 harness to a '93 ECU, or a '93 harness to a '91 ECU? Then customers who run into this situation don't have to find another ECU or repin the whole harness.

Since I had this customer, Bryant, who had this very situation at hand, and since I happened to be going near where he lived on a recent road trip, I decided to whip up a prototype and give it a try.







There it is plugged into a 3SGE ECU as an example. This first one came out a little rough, the production model will be cleaner.

And here it is plugged into the car:



The jumper harness worked PERFECTLY. It fired up the first try and is running great, no codes and no problems at all

If anyone wants one of these jumper harnesses let me know, I'm currently building them to order.

Other applications for this setup include plug and play jumper harnesses for standalone units that don't already have a plug and play setup, like perhaps 3SGTE/Autronic, and so on.

-Doc

[Dr_Tweak]

Well done. Actually, I would be happy to admit that despite being fairly skilled with a soldering iron, the care needed to construct these properly and consistently requires as many as four hours each, especially for the first batch. Also not even taken into consideration is that until a few posts ago I wasn't able to locate the 64-pin PCB connector from Toyota, leaving one of two options to get it: 1. order 3000 units (minimum order from Tyco) or 2. purchase them from a 3rd party vendor at a cost of $75.00+ (not kidding). Fortunately I was able to find a happy medium between the order quantity and the $75 pricetag that allowed me to put these together with a pricetag that made sense (ie, cheaper and/or easier than finding a new ECU).

One last thing. In case it's been forgotten, I DO run a shop, and we DO charge $80/hour as our base shop rate (tuning is more). So if I take 2-4 hours to build something, technically, if it were a one-off part that I was building for a customer's car in the shop, it would cost $80 an hour, or $160 to $320 just for labor. Obviously that would put the pricetag of these out of the question, so I make an exception. (A similar situation occurs with wiring harness conversions, we charge $399 and it takes more than 8 hours, which would technically be $640, but we feel that would be too expensive. For that matter, we often spend upwards of 40 hours on doing an engine swap, but we simply cannot charge $80 an hour for a swap because that would be $3200! Instead we charge a "flat rate" of $1900 because otherwise, swaps would just be too expensive to do!!!)

-Doc

This post has been edited by Dr_Tweak: Jan 2, 2008 - 4:26 PM

[WannabeGT4]

Well done. Actually, I would be happy to admit that despite being fairly skilled with a soldering iron, the care needed to construct these properly and consistently requires as many as four hours each, especially for the first batch. Also not even taken into consideration is that until a few posts ago I wasn't able to locate the 64-pin PCB connector from Toyota, leaving one of two options to get it: 1. order 3000 units (minimum order from Tyco) or 2. purchase them from a 3rd party vendor at a cost of $75.00+ (not kidding). Fortunately I was able to find a happy medium between the order quantity and the $75 pricetag that allowed me to put these together with a pricetag that made sense (ie, cheaper and/or easier than finding a new ECU).

-Doc

So four hours of labor and a connector close to $75.00. No wonder you were charging so much. Hopefully the part number I posted is correct and you'll be able to lower your price closer to, if not under the cost of a used ECU.