Which ecu should I use?

[ogbimmer]

I know this is probably a dumb question but I am buying a 86 325e automatic for my girlfriend. I am going to be putting my 325i head and stuff on it so I was going to run it with my 325i ecu. however the ecu I have is for a 325i manual. Is there a different ecu for a 325i automatic, and If so what is it called so I can look for it.

[Rigmaster]

same ecu for auto or manual.

you'll have to completely convert it to use the 325i ecu, this means the head, injectors, engine wiring harness, crank sensor, AFM, etc, etc.

[ZM Blue Devil]

why is the head bad?

[matias88e30]

I think he wanted some hp for her girlfriend

[Chester]

Hi
325i ecu is right for use here. Don't hesitate for using this.
Thanks

[Chester]

Hi
325i ecu is right for use here. Don't hesitate for using this.
Thanks

[mikeedler]

this thread understand i not good so.

[Rigmaster]

understand what I don't is 2 posts Chester did make however zero posts has he

>>???

[CabbE30]

I can has translator for this thread i need?

[ogbimmer]

Im so lost... I just want more power for her then the standard eta has. Im already pulling out the engine and refreshing it and with my i head on it the compression will be lowered incase I ever want to do a small turbo set up also like 5 psi. I have just never had a auto e30 before so I figured I would ask.

[ogbimmer]

understand what I don't is 2 posts Chester did make however zero posts has he

>>???

thats true actually think I

[RainierHooker]

Ok, since no one else is gonna say it...

An 87-on 325i ECU (which is Motronic 1.3) will only work with a '87 and later engine harness. In order to use such an ECU you would need to change among other things, the harness, you plug wires, the distributor/rotor, and I think the Cam-sensor. Look up Motronic 1.3 upgrade in the technical forums for more details.
The '86 and earlier eta engine management is Motronic 1.0 or 1.1 depending on the year (your '86 is 1.1, and should have a -027 ECU). This is just fine for most appliactions however, the rev-limit will be 4500 RPM, much lower than the "i" head will allow. You can have chip made for your eta ECU that will raise the limiter, or you could swap the harness and ECU from the later cars for about the same money.

PS: before you put an "I" head on an eta bottom end, do yourself a favor and puruse the technical sections of this forum. Thsi is especially important when it comes to valve clearances with and "i" head and eta pistons...

[ogbimmer]

Ok, since no one else is gonna say it...

An 87-on 325i ECU (which is Motronic 1.3) will only work with a '87 and later engine harness. In order to use such an ECU you would need to change among other things, the harness, you plug wires, the distributor/rotor, and I think the Cam-sensor. Look up Motronic 1.3 upgrade in the technical forums for more details.
The '86 and earlier eta engine management is Motronic 1.0 or 1.1 depending on the year (your '86 is 1.1, and should have a -027 ECU). This is just fine for most appliactions however, the rev-limit will be 4500 RPM, much lower than the "i" head will allow. You can have chip made for your eta ECU that will raise the limiter, or you could swap the harness and ECU from the later cars for about the same money.

PS: before you put an "I" head on an eta bottom end, do yourself a favor and puruse the technical sections of this forum. Thsi is especially important when it comes to valve clearances with and "i" head and eta pistons...

thanks for the help man. I could technically just take the harness out of my 90 325i also right? Im going to get a megasquirt harness for my stand alone so that shouldnt be a problem. And I will look up so me more stuff in the technical forum.

[Rigmaster]

same ecu for auto or manual.

you'll have to completely convert it to use the 325i ecu, this means the head, injectors, engine wiring harness, crank sensor, AFM, etc, etc.

Ok, since no one else is gonna say it...

An 87-on 325i ECU (which is Motronic 1.3) will only work with a '87 and later engine harness. In order to use such an ECU you would need to change among other things, the harness, you plug wires, the distributor/rotor, and I think the Cam-sensor. Look up Motronic 1.3 upgrade in the technical forums for more details.
The '86 and earlier eta engine management is Motronic 1.0 or 1.1 depending on the year (your '86 is 1.1, and should have a -027 ECU). This is just fine for most appliactions however, the rev-limit will be 4500 RPM, much lower than the "i" head will allow. You can have chip made for your eta ECU that will raise the limiter, or you could swap the harness and ECU from the later cars for about the same money.

PS: before you put an "I" head on an eta bottom end, do yourself a favor and puruse the technical sections of this forum. Thsi is especially important when it comes to valve clearances with and "i" head and eta pistons...

I kinda covered the engine wiring harness bit, I think...


;)

[James Crivellone]

Ok, since no one else is gonna say it...

An 87-on 325i ECU (which is Motronic 1.3) will only work with a '87 and later engine harness. In order to use such an ECU you would need to change among other things, the harness, you plug wires, the distributor/rotor, and I think the Cam-sensor. Look up Motronic 1.3 upgrade in the technical forums for more details.
The '86 and earlier eta engine management is Motronic 1.0 or 1.1 depending on the year (your '86 is 1.1, and should have a -027 ECU). This is just fine for most appliactions however, the rev-limit will be 4500 RPM, much lower than the "i" head will allow. You can have chip made for your eta ECU that will raise the limiter, or you could swap the harness and ECU from the later cars for about the same money.

PS: before you put an "I" head on an eta bottom end, do yourself a favor and puruse the technical sections of this forum. Thsi is especially important when it comes to valve clearances with and "i" head and eta pistons...

Close, but the ETA ECU's are Motronic 1.0 (No CEL, 021 and 027 ECU Tags, 27 had a removable chip, 21 did not), the 153 M20B25 ECU is Motronic 1.1 (Dual Board, 4 CEL Codes), and 88+ (or LATE 87 Builds) have the 380, 524, or 173 Single Board Motronic 1.3 ECU