kerristallax Posted July 31, 2012 Share Posted July 31, 2012 I should start a build thread here soon for my soon-to-be RB25 280z, but I have a simpler question first. I ordered an RB25det engine/transmission package off eBay from an importer in Texas. I received it last Friday. They had set the ECU on top of the motor, and something looks to have hit it in transit. It has a dent on the back. Is there any way to power on and test the ECU? The seller gave me a bunch of hassle about my request that they replace their damaged part, but is saying now that they will replace the ECU if I install it and it doesn't start, but it's going to be impossible to have the car ready to start up in their 14-day window. Maybe just open the ECU cover and look for damage? Quote Link to comment Share on other sites More sharing options...
cgsheen Posted July 31, 2012 Share Posted July 31, 2012 Take the lid off and look. Unless you know someone with a running RB25DET using a stock ECU you can test it in... Quote Link to comment Share on other sites More sharing options...
RS Speed Posted July 31, 2012 Share Posted July 31, 2012 Either test on another RB or you can plug the ecu into the harness and power up the wires with a 12v battery that would normally get wired into your cars harness and see if the ecu comes to life... you can spin the CAS and see if the injectors click to see if shes good to go. On a side not I've seen worse looking dents on ecu's that still worked fine. Before powering it up though I'd open the case up and make sure the dented part is not contacting any surfaces on the board causing shorts. Quote Link to comment Share on other sites More sharing options...
kerristallax Posted July 31, 2012 Author Share Posted July 31, 2012 (edited) I don't know anyone else with a stock RB in my neighborhood. Thursday I'm going to dig into the motor a little bit further to make sure everything looks right, I'll try opening the ECU up and making sure that it's not contacting the board inside, and then see if I can power it up and turn the CAS by hand. This motor still has the little "Sealed" sticker over the one bolt on the CAS, I'll mark where it was before removing. Thanks Edited July 31, 2012 by kerristallax Quote Link to comment Share on other sites More sharing options...
kerristallax Posted August 2, 2012 Author Share Posted August 2, 2012 (edited) Looking through the stickied wiring how-to now... It looks like if I apply +12v to the wires for pins 43 (start signal), 45 (ignition power wire), and 58 (ecu backup, unswitched +12v), and ground the engine block, it should power on? Unfortunately someone has removed the two blue relays off this motor set. To do this basic test, can I jump the wires at the relay connection for the thick red wire (ignition power relay) and the thick black/red stripe wire? It looks like this is the missing link, but I'd hate to ground something out and let the magic smoke out. Edit: this sounds like a bad idea in retrospect. Running a separate power to the thick red wire on the ignition power relay would probably be the better thing to do, if this is what's needed to power it up. I have a new wiring harness on order from Wiring Specialties. should be here in about 2 weeks... I looked in my miscellaneous used parts bin, but I don't have any 4-pin relays that are the same as the ones on the rb25 harness. Edited August 2, 2012 by kerristallax Quote Link to comment Share on other sites More sharing options...
kerristallax Posted August 2, 2012 Author Share Posted August 2, 2012 Oh, and the dent in the cover was touching the circuit board inside lightly, but I can't see any visible damage on the board. Quote Link to comment Share on other sites More sharing options...
cgsheen Posted August 2, 2012 Share Posted August 2, 2012 I'm sure you know not to apply power if any part of the case is in contact with the circuit board. Denting probably happened in shipping? Still, I don't know if I'd trust the circuit board not to have, or develop problems later - have stress cracks, affected a solder joint, etc... If you'd plugged it in to test it without taking off the lid, it probably would have fried. Hmmm... Quote Link to comment Share on other sites More sharing options...
kerristallax Posted August 2, 2012 Author Share Posted August 2, 2012 Yes, I removed the dented case before doing anything. It is still off as we speak. I'm sure the ECU was dented on the ride between the importer in Texas and my shop, the way the plastic they wrapped the engine was torn right there over the ECU. Quote Link to comment Share on other sites More sharing options...
kerristallax Posted August 3, 2012 Author Share Posted August 3, 2012 The seller is going to exchange the ECU for another one. Hopefully I'll have better luck this time. Quote Link to comment Share on other sites More sharing options...
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