EJ20G Swap - No Spark on 3rd Cylinder
Posted: Sat Nov 11, 2006 4:29 am
Hey,
I'm the guy with the WR-blue '91 Legacy Turbo who was asking you all the questions about transplanting and wiring up an EJ20G last winter.
I haven't posted on the board in a while, but I'm still trying to complete the EJ20G swap in my '91 Legacy Turbo:
http://bbs.legacycentral.org/viewtopic. ... swap+write
I've got the engine in, all the wiring modified to run with the SVX (6-channel) ignitor on 4-channels from a stock Ver.1 JDM WRX ECU. The car starts up, but there's no spark on the 3rd cylinder coil-on-plug.
We're eliminated the fact that the coil might be bad and we've traced the problem to the ECU not sending a "correct" signal to the 3rd ignition channel. The SVX ignitor is fine too. The problem is that the JDM WRX ECU isn't sending out spark on the 3rd ignition channel. We've even measured the voltage on this wire right by the ECU harness and it's not getting the same voltage as channels #1, #2 and #4. Most of the time the voltage is 0 and sometimes is "blips" to 0.5v. The other 3 ignition channels are getting a nice and smooth 1.5v.
When we pulled the coil plugs off the engine, #1, #2 and #4 had spark, but #3 doesn't.
The car's now at a car electronics specialists' shop and he says that there aren't any problems with the ECU or wiring. I've even tried running the car with a spare Ver.1 WRX ECU, but the same thing's happening. No spark on the 3rd ignition channel.
Does anyone have any idea what could be causing the ECU to send out the ignition signal to only 3 of the 4 channels? How does a Ver.1 JDM WRX ECU know when to send out a signal to a specific ignition channel? Is it solely based on the signal it receives from the cam sensor?
How does a cam sensor get its information about the position of the cam? Does the right-top cam sprocket have a magnet on it, whose position the cam sensor picks up? Is it possible that my cam sprocket is damaged and be causing this?
...Does this sound like a timing issue to anyone? I just wanna double check before I pull off the timing and re-install everything again.
Any help would be greatly appreciated
Thanks in advance,
PC.
I'm the guy with the WR-blue '91 Legacy Turbo who was asking you all the questions about transplanting and wiring up an EJ20G last winter.
I haven't posted on the board in a while, but I'm still trying to complete the EJ20G swap in my '91 Legacy Turbo:
http://bbs.legacycentral.org/viewtopic. ... swap+write
I've got the engine in, all the wiring modified to run with the SVX (6-channel) ignitor on 4-channels from a stock Ver.1 JDM WRX ECU. The car starts up, but there's no spark on the 3rd cylinder coil-on-plug.
We're eliminated the fact that the coil might be bad and we've traced the problem to the ECU not sending a "correct" signal to the 3rd ignition channel. The SVX ignitor is fine too. The problem is that the JDM WRX ECU isn't sending out spark on the 3rd ignition channel. We've even measured the voltage on this wire right by the ECU harness and it's not getting the same voltage as channels #1, #2 and #4. Most of the time the voltage is 0 and sometimes is "blips" to 0.5v. The other 3 ignition channels are getting a nice and smooth 1.5v.
When we pulled the coil plugs off the engine, #1, #2 and #4 had spark, but #3 doesn't.
The car's now at a car electronics specialists' shop and he says that there aren't any problems with the ECU or wiring. I've even tried running the car with a spare Ver.1 WRX ECU, but the same thing's happening. No spark on the 3rd ignition channel.
Does anyone have any idea what could be causing the ECU to send out the ignition signal to only 3 of the 4 channels? How does a Ver.1 JDM WRX ECU know when to send out a signal to a specific ignition channel? Is it solely based on the signal it receives from the cam sensor?
How does a cam sensor get its information about the position of the cam? Does the right-top cam sprocket have a magnet on it, whose position the cam sensor picks up? Is it possible that my cam sprocket is damaged and be causing this?
...Does this sound like a timing issue to anyone? I just wanna double check before I pull off the timing and re-install everything again.
Any help would be greatly appreciated
Thanks in advance,
PC.