New Harness/ rewiring engine, Help rewiring engine Options

[m2736185]

Im heading to the junkyard tomorrow....with the assumption that they used the 96 intake manifold can I use a 96+ engine harness and ECU? will all the plugs fit into the ecu?

[mandrek]

well, if the manifold is an indicator then, there is a chance that it is indeed a 96 motor.. best way to check would be to see if there is a sensor on the crank (on the oil pump housing) and if the dizzy is just a straight bolt in, or if it has elongated holes that would allow for it to be rotated some.. if it is the straight bolt in then it is a 96+ for sure. if not.. well, it could be that they put an OBDI dizzy on it to try to make it work...

if all the signs point to it being a 96 then yeah, a 96 harness and ECU should be the key for you..

[m2736185]

The motor is indeed a 96. I got the vin number off it. The dizzy was changed by the previous owner trying to fix the problem so that wouldnt be much help. I am not sure the difference between the 94 and the 96 intake manifold or TB so I havent been able to check that.

[m2736185]

Here are some pictures idk if anyone can identify the year the intake manifold or TB is from pictures









ECU found in the car

Looks like they did some modification to the harness


This post has been edited by m2736185: Feb 24, 2012 - 1:45 PM

[mkernz22]

i don't believe the car should have a 4a-g ecu in it, but i've never see a 7a before.

[mandrek]

OMG!!!

well that is defiantly an OBDII mani.. as far as i know any harness and ecu from 96+ would work for ya.. Smaay should be able to give you a more definitive answer. as he has worked on SOOOOO many 7A's....

i don't believe the car should have a 4a-g ecu in it, but i've never see a 7a before.

yeah lol, that may be an issue as well. lol

[m2736185]

Yea, that was the first person I thought of asking, but he said he doesnt know if the ECUs have the same number of plugs.

Doesnt seem like many people have any experience with the OBDI -II swaps.

Well, I guess I have a complete 96 engine and tranny swap...then who ever did the swap realized the ECU wasnt gonna work so they assumed one from a corolla would.

Since everything in the engine is 96 I would really prefer to just swap a 96 harness and ecu on there, but I need to know if its gonna work....otherwise im gonna have to track down a 94/95 ECU, harness, TB, mani, dizzy.

Can anyone shed some light on this? It will be one extra celica saved from the junk yard

[mandrek]

Yea, that was the first person I thought of asking, but he said he doesnt know if the ECUs have the same number of plugs.

Doesnt seem like many people have any experience with the OBDI -II swaps.

Well, I guess I have a complete 96 engine and tranny swap...then who ever did the swap realized the ECU wasnt gonna work so they assumed one from a corolla would.

Since everything in the engine is 96 I would really prefer to just swap a 96 harness and ecu on there, but I need to know if its gonna work....otherwise im gonna have to track down a 94/95 ECU, harness, TB, mani, dizzy.

Can anyone shed some light on this? It will be one extra celica saved from the junk yard

no just get the 96 harness and ecu..

[m2736185]

I guess that's the best option. If the interior doesn't plug in I suppose I will have to rewire the interior. Where can I get a wiring diagram if the worse comes to that?

[mandrek]

there are some in the online BGB in the stickies.

[m2736185]

Most of the online BGB are down.

Well, my harness came in today. Came from a 97, but it was cut at some point. I gotta figure out what part was cut.

I got it running today, but it was running really rough with the rpms jumping. Im guessing that is more an issue with the distro that the ECU. Now the fun begins gonna try to identify all the conncections on the wire harness before I proceed. I will update with some pictures.

This post has been edited by m2736185: Mar 3, 2012 - 10:45 AM

[m2736185]

I got the harness today, but there is a nice piece of the sections that was cut. Ill see if I can get a pic

This post has been edited by m2736185: Mar 4, 2012 - 1:26 PM

[Kwanza26]

Holy crap that b!tch is jury rigged... anyway... all i was gonna say is... JT2AT vin code is Celica ST. J for japan... T for toyota... 2 for vehicle type... A for engine type (A for celica ST... S for celica GT)... T for chassis/model. This is universal for most Toyota models originating prior to 1996.

[ricochet1490]

I cannot shed any light onto the the wiring harness problem, but if you are still using that 4age ecu, that would be the FIRST thing I would change. my .02$

[m2736185]

Yes, the ECU is going to be changed, but it wont do any good until I can make sense of this wiring.

I wish the previous owner would have left the 4age in there.

Anyways I think the reason I dont see a few of the connectors is...the harness has been cut. I have been unable to locate the MAP sensor, o2 sensor, sensor on tranny and a few others. Here is a pic if anyone can identify this part.

[mandrek]

Yes, the ECU is going to be changed, but it wont do any good until I can make sense of this wiring.

I wish the previous owner would have left the 4age in there.

Anyways I think the reason I dont see a few of the connectors is...the harness has been cut. I have been unable to locate the MAP sensor, o2 sensor, sensor on tranny and a few others. Here is a pic if anyone can identify this part.

that big bundle of wires with the white plastic clip on it looks like the harness bundle for the Diagnostics port.

[m2736185]

I think you might be right. I just looked at my GT and it has a similar plastic clip that splits into the diagnositc port....and the igniter...i might need that.

This post has been edited by m2736185: Mar 4, 2012 - 2:05 PM

[toyotatech3]

Yes, the ECU is going to be changed, but it wont do any good until I can make sense of this wiring.

I wish the previous owner would have left the 4age in there.

Anyways I think the reason I dont see a few of the connectors is...the harness has been cut. I have been unable to locate the MAP sensor, o2 sensor, sensor on tranny and a few others. Here is a pic if anyone can identify this part.

that big bundle of wires with the white plastic clip on it looks like the harness bundle for the Diagnostics port.

there is a pic of it in my profile. mine is a 97 st

[m2736185]

So I wish that was just the diagnostic port, but the wires for the igniter is also in that bundle and the 2 wires to the left are for the MAP sensor.

Anyways the harness i bought is also missing the battery cables so I have to splice in my own. I noticed there are 2 wires running to the 100 amp fuse in the fuse block. One is white and one is black. I am guessing one of these go to the battery and then there is another cable somewhere that goes to the starter and alternator?

[m2736185]

She Lives!

I put in the new ECU for the 7A, fresh gas, checked the pressure of the gas (26-34 PSI). With the help of starter fluid and a few tries until the battery was almost dead it started up. Runs 100x better with the 7A ecu. I guess the previous owners that had the blacktop in there left the exhaust the had on there. Its super loud it make the 7a feel like its faster than my 5s.

Only scary part was after I ran the car for a test drive around the block...I took the key out of the ignition and you would think the car would turn off right? Nope, I ran over to the battery and unhooked the battery cables and still nothing. I was about to pull the cables from the dizzy but it finally turned off.

Still gotta put in the new harness
Figure out why the fuel pump doesnt turn on without my jumping it.

This post has been edited by m2736185: Mar 18, 2012 - 2:28 PM