mellonman Posted May 2, 2016 Share Posted May 2, 2016 To run a walbro 400 and above you need to do this mod, the pump will not run on the low voltage 9v off boost voltage the fuel pump ecu gives out , this mod is to give you a 12v feed constant but to still give you the safety features of the stock fuel ecu ie fuel cut in the event of a crash!!!! If you dont fit the relay and wire directly to the 12v you will always have the fuel pump running as soon as you switch the ignition Its your call pyro Quote Link to comment Share on other sites More sharing options...
EleCtRoN Posted May 3, 2016 Share Posted May 3, 2016 I get the part that you need to get a wire directly from the battery to the relay so the pump gets the 12V all the time when the car is running but what I was after is if this 12V mod is necessary http://mkiv.com/techarticles/12v_mod/12v_mod.htm since the relay will trigger itself on voltage between 1,6V - 12V so from what I understand you dont need to do the 12V mod to the ECU and just take the cabel that feeds the pump from the ECU and run it by the relay that triggers the 12V from the battery, the original fuelpump cabel gives out 9-12V without the mod done but that shouldnt bother the relay that feeds the pump with 12V all the time since the relay will trigger itself on voltage between 1,6V - 12V. Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 3, 2016 Share Posted May 3, 2016 No The relay coil is energized by the 9v 12v feed and solid 12v runs through the contacts to the pump You did look at the wiring diagram I done right its very simple http://www.mkivsupra.net/vbb/showthread.php?272714-12v-mod-will-this-work Quote Link to comment Share on other sites More sharing options...
babou88 Posted March 16, 2017 Share Posted March 16, 2017 Good evening. I have just installed a DW200 fuel pump on my 1998 Vvti Supra TT. (the car start fine with this new pump, not tested yet in "hard condition" , just one start and it work) I have checked all "12V mod fuel pump" here and on supraforums.com.au, and i wanted to do the mod on my car, but i don't find the Fuel Pump ECU on my Vvti TT !! can someone tell me where it's located ? (or if there is any fuel pump ECU on a Vvti TT ?) in the trunk, where it's supposed to be, there is just the trunk light and a red electric stuff, but nothing to do with the pump (no big wire ) can someone help me? does this mod isn't needed on a Vvti TT ? Quote Link to comment Share on other sites More sharing options...
Glanza_Mike Posted March 16, 2017 Share Posted March 16, 2017 I've done this mod on my vvti and can tell you the ecu is in the same place. It's kinda behind the the light, attached to yhe back of the plastic panel, you can't see it. You have to put your hand in and feel around. Ohhh errr Quote Link to comment Share on other sites More sharing options...
babou88 Posted March 17, 2017 Share Posted March 17, 2017 thanks Glanza_mike ! finally found it ! (my fingers are dirty but nothing wet ... ) mod done with relay of course! car start good... need to test it harder before trackday at Dijon-Presnois next week end.... Quote Link to comment Share on other sites More sharing options...
Glanza_Mike Posted March 17, 2017 Share Posted March 17, 2017 You're welcome mate glad it's sorted. Quote Link to comment Share on other sites More sharing options...
EleCtRoN Posted June 18, 2017 Share Posted June 18, 2017 (edited) I have the walbro 450LPH pump installed and working but I get that strange ticking from the relay now and then as for some others here. I run an new cabel from the battery to the relay and new cabels to the fuel pump. Is this the right way to connect the "trigger" cabel to the fuel ecu harness? It is spliced in to the RED/BLUE wire. Or should I do something else also to get rid of the strange on/off ticking of the relay? Edited June 18, 2017 by EleCtRoN (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 18, 2017 Share Posted June 18, 2017 I have the walbro 450LPH pump installed and working but I get that strange ticking from the relay now and then as for some others here. I run an new cabel from the battery to the relay and new cabels to the fuel pump. Is this the right way to connect the "trigger" cabel to the fuel ecu harness? It is spliced in to the RED/BLUE wire. Or should I do something else also to get rid of the strange on/off ticking of the relay? [ATTACH=CONFIG]219675[/ATTACH] You should get a correct drop out voltage relay Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted June 18, 2017 Share Posted June 18, 2017 I'm sure I read on here some time ago that the constant relay ticking was a result of using a relay with a 9v or 12v trigger, when it really needs one with 5v (or something to that end) Chris Wilson is the man to ask Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 18, 2017 Share Posted June 18, 2017 I have linked the correct relay on the second page already Quote Link to comment Share on other sites More sharing options...
EleCtRoN Posted June 18, 2017 Share Posted June 18, 2017 The thing is that I got the exact relay that you linked to. So either it is bad or I have spliced into the wrong wire Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 19, 2017 Share Posted June 19, 2017 (edited) Ok Check that you have the 9v supply from the fuel pump ecu to the coil of the relay and the 12v to the ecu through the contacts to the pump. Its not uncommon for the fuel pump ecu to fail if thats what you have set up then youneed to monitor the voltages to the coil and see if your getting a drop in voltage. That being said if you have a bad connection this would also cause you problems. Also check that earth you have done not sure that insulation sound deadening conducts electricity Edited June 19, 2017 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
EleCtRoN Posted June 25, 2017 Share Posted June 25, 2017 I have it set up like this now, any thoughts? The chassi ground is under the same bolt that holds the fuel ecu but I will check it. Should I run a wire between the factory fuel ecu 12V (blue wire) to the new wire that goes from the relay pin 30 to the new fuel pump? Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 25, 2017 Share Posted June 25, 2017 No that will give the pump 12v directly and bybass the relay, Quote Link to comment Share on other sites More sharing options...
EleCtRoN Posted June 25, 2017 Share Posted June 25, 2017 All right! So otherwise its all good then? Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 25, 2017 Share Posted June 25, 2017 As long as 30 and 87 are the switch contact, and 85 and 86 are the coil, if its still dropping out check that earth you have used if still then you may have to sit with a meter are watch the voltages are to the relay coil from the fuel ecu Quote Link to comment Share on other sites More sharing options...
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