2002 JDM EJ207 swap starts won't rev - Solved!

Bolt-on · 07-06-2022, 06:07 PM

I'm putting a JDM V7 2002 STi engine in a Factory Five 818R kit car. The engine is cable throttle, AVCS, no TGV factory intake.

I pruned what was probably a 2002 WRX chassis harness to fit the 818. The JDM engine came with engine harness only and a B1 code ECU from a 2005 immobilized STi. (I figured this out when it wouldn't start thanks to iWire!) I bought a JDM V7 ECU on ebay, code V8.

I have had to re-pin the WRX ecu connectors for the main relay, fuel control, and intake air temp sensor, and add pins and wires for the AVCS rear cam sensors and solenoids. I have printed out several wiring diagrams. The JDM harness closely matches one for a 2005 STi, and doesn't match the others.

I can read OBD codes but not monitor functions. I have one O2 sensor code P0037, probably because I don't have a rear O2 sensor.

It starts right up on all cylinders and has a low surging idle, barely running. It will not rev but dies with throttle.

I have hundreds of hours into just the wiring.

I tried to connect a Tactrix cable but my computer isn't doing it. I have had great success on other projects with Megasquirt. I'm wondering if I should go that way or keep trying with the Subaru ECU.

I may have missed an important ECU pin. The ebay ECU may be bad or tuned for a different car. I checked for vacuum leaks. Fuel pressure is good. All cylinders fire smoothly.

I'd appreciate any suggestions!

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Bolt-on · 07-07-2022, 03:20 PM

I unplugged the MAF and it runs. Now I need to figure out what that means.

Bolt-on · 07-07-2022, 06:07 PM

Solved. I installed the MAF sensor backwards. Turned the intake pipe around and it runs like a champ!

NordyPi · 07-08-2022, 06:18 PM

Quote:

Originally Posted by Bolt-on

Solved. I installed the MAF sensor backwards. Turned the intake pipe around and it runs like a champ!

That must have been scary. Glad the fix was easy, even if it was stressful at first?

07-06-2022, 06:07 PM	#1
Bolt-on Scooby Newbie Member#: 104832 Join Date: Jan 2006 Location: Lander, Wyoming Vehicle: 05 STi CGM	2002 JDM EJ207 swap starts won't rev - Solved! I'm putting a JDM V7 2002 STi engine in a Factory Five 818R kit car. The engine is cable throttle, AVCS, no TGV factory intake. I pruned what was probably a 2002 WRX chassis harness to fit the 818. The JDM engine came with engine harness only and a B1 code ECU from a 2005 immobilized STi. (I figured this out when it wouldn't start thanks to iWire!) I bought a JDM V7 ECU on ebay, code V8. I have had to re-pin the WRX ecu connectors for the main relay, fuel control, and intake air temp sensor, and add pins and wires for the AVCS rear cam sensors and solenoids. I have printed out several wiring diagrams. The JDM harness closely matches one for a 2005 STi, and doesn't match the others. I can read OBD codes but not monitor functions. I have one O2 sensor code P0037, probably because I don't have a rear O2 sensor. It starts right up on all cylinders and has a low surging idle, barely running. It will not rev but dies with throttle. I have hundreds of hours into just the wiring. I tried to connect a Tactrix cable but my computer isn't doing it. I have had great success on other projects with Megasquirt. I'm wondering if I should go that way or keep trying with the Subaru ECU. I may have missed an important ECU pin. The ebay ECU may be bad or tuned for a different car. I checked for vacuum leaks. Fuel pressure is good. All cylinders fire smoothly. I'd appreciate any suggestions! * Registered users of the site do not see these ads. Last edited by Bolt-on; 07-07-2022 at 06:08 PM.

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07-07-2022, 03:20 PM	#2
Bolt-on Scooby Newbie Member#: 104832 Join Date: Jan 2006 Location: Lander, Wyoming Vehicle: 05 STi CGM	I unplugged the MAF and it runs. Now I need to figure out what that means.

07-07-2022, 06:07 PM	#3
Bolt-on Scooby Newbie Member#: 104832 Join Date: Jan 2006 Location: Lander, Wyoming Vehicle: 05 STi CGM	Solved. I installed the MAF sensor backwards. Turned the intake pipe around and it runs like a champ!