TSI_SVT Posted April 21, 2014 Report Share Posted April 21, 2014 What would be a few things that would cause intermittent power loss to the ECU? Sometimes it'll power up, along with my SAFC, when I crank it then once I start driving it'll randomly lose power and shut the car down. Other times it'll power up with the ignition in the On position but as soon as I turn the key to crank it'll lose power. I've gone over wiring under hood because I was assuming it was a short or poor ground. (I had pulled head and replaced head gasket.) I've yet to find a way to restore power consistently. Usually I just cross my fingers and hope for the best. I'm next guess is a relay but wanted to get some input before proceeding. Link to comment Share on other sites More sharing options...
Skullzaflare Posted April 21, 2014 Report Share Posted April 21, 2014 most likely fuseable likes Link to comment Share on other sites More sharing options...
scott87star Posted April 21, 2014 Report Share Posted April 21, 2014 ECU power comes from the ECU relay which is just above and behind the ECU. It's activated by key on and start, two different positions of the ignition switch as well as needing clean grounds at positions 1, 9, 11. Sub-fusible link 2 feeds the ECU relay directly. Ground 1 is on the inner fender next to the air can, ground 9 by the ignitor and ground 11 mid way between the battery negative and the engine block. Make sure all that is scrupulously clean. Link to comment Share on other sites More sharing options...
TSI_SVT Posted April 21, 2014 Author Report Share Posted April 21, 2014 ECU power comes from the ECU relay which is just above and behind the ECU. It's activated by key on and start, two different positions of the ignition switch as well as needing clean grounds at positions 1, 9, 11. Sub-fusible link 2 feeds the ECU relay directly. Ground 1 is on the inner fender next to the air can, ground 9 by the ignitor and ground 11 mid way between the battery negative and the engine block. Make sure all that is scrupulously clean.Thank you for the detailed response. Once it cuts off again I will check power to and out of the relay. I will go ahead and double check all grounds. Most of my engine bay wiring has been tucked inside the inner fenders so I will have a little harder time . Link to comment Share on other sites More sharing options...
Shelby Posted April 27, 2014 Report Share Posted April 27, 2014 my guess is a bad ign swt but never hurts to check all grounds and power feeds many years ago the Tainters was chaseing an engine miss,, problem was coil power wire was just laying on terminal and would bounce around causeing a miss Link to comment Share on other sites More sharing options...
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