yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 Thanks for all the help fellas.. Quote Link to comment Share on other sites More sharing options...
Ghostchips Posted January 13, 2020 Share Posted January 13, 2020 5 hours ago, yetchh said: Ok cheers, how do I fix this? Should the ecu run on its own separate relay? Where would I find these flywheel diodes in a 70's mazda? I thought the flywheel diodes would be in the ECU itself? If not, i put a "schotcky diode" to short a relay, but only if the relay is hooked up backwards. Seems to flywheel ok for the most part. Quote Link to comment Share on other sites More sharing options...
Stu Posted January 13, 2020 Share Posted January 13, 2020 From memory there is an updated wiring diagram on the link FAQ on how the ecu needs to be powered. I can dig up the wiring diagrams for the last few customers cars Ive wired up if you want too. Quote Link to comment Share on other sites More sharing options...
yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 11 minutes ago, Stu said: From memory there is an updated wiring diagram on the link FAQ on how the ecu needs to be powered. I can dig up the wiring diagrams for the last few customers cars Ive wired up if you want too. Yeah bro that would be good.. It does say in both the v3 and v5 installation manuals that inj, ign and ecu can be on the same relay, I guess I just took a shortcut and put the fuel pump on there as well.. Quote Link to comment Share on other sites More sharing options...
kpr Posted January 13, 2020 Share Posted January 13, 2020 where does the 12v+ come from on the coil of fuel pump relay ? Sounds like how you have it setup should work. Ideally you want your main power feed from battery -> straight to fuse box/ fuses . then out of fuses to relays I like to run the ecu on its own relay triggered by key on. Then a second relay for the fuel pump. ecu supplies negative to coil Then if you want to get fancy; As well as the fuel pump relay doing the fuel pump. use it to trigger the coil on a 3rd relay, which does all your injectors, coils etc. This way if the engine stops for any reason, the ecu turns off the fuel pump and also kills power to injectors and coils and what ever else is on the 3rd relay. just bit of a safety feature 2 Quote Link to comment Share on other sites More sharing options...
Dudley Posted January 13, 2020 Share Posted January 13, 2020 ^ incorrect 1 Quote Link to comment Share on other sites More sharing options...
yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 1 hour ago, kpr said: where does the 12v+ come from on the coil of fuel pump relay ? Sounds like how you have it setup should work. Ideally you want your main power feed from battery -> straight to fuse box/ fuses . then out of fuses to relays I like to run the ecu on its own relay triggered by key on. Then a second relay for the fuel pump. ecu supplies negative to coil Then if you want to get fancy; As well as the fuel pump relay doing the fuel pump. use it to trigger the coil on a 3rd relay, which does all your injectors, coils etc. This way if the engine stops for any reason, the ecu turns off the fuel pump and also kills power to injectors and coils and what ever else is on the 3rd relay. just bit of a safety feature Fuel pump feed comes from the +common fuse box fed by the a 12v battery direct relay, I drew it out... 1 Quote Link to comment Share on other sites More sharing options...
yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 *Fixed Ran the ecu feed straight from the ignition feed instead of the + common Thanks chaps, can always count on you lot to help troubleshoot for us plebs 2 Quote Link to comment Share on other sites More sharing options...
kpr Posted January 13, 2020 Share Posted January 13, 2020 so is like this now and works? can kinda see how that would fix the issue to a point. bit of a band aid fix though. with ecu wired on that side what ever is backfeeding that relay wont be enough to power the ecu, so engine will shut off. you may still end up with battery draining issues or other weird stuff I still think your better off to ditch that "main" relay before fuse box and run a couple of relays after the box one for ecu and other for the rest, fuel pump can stay how it is. assuming "to ecu earth" is the fuel pump output from ecu Quote Link to comment Share on other sites More sharing options...
yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 Yeah I'll put a relay and fuse for the main ecu power separate from the main relay, the rest should be good like that. The coil energiser for the pump came from the main relay like everything else then to the ecu switched earth, I just ran it straight to the ign feed to see if it fixed it which it did. Quote Link to comment Share on other sites More sharing options...
yetchh Posted January 13, 2020 Author Share Posted January 13, 2020 This is from the link manual.. Guess I could just run the fuel pump to trigger the main relay instead of ign and run only the ecu from ign then it would be set up as you said further up.. Quote Link to comment Share on other sites More sharing options...
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