subaruguru Posted August 22, 2011 Share Posted August 22, 2011 Is there any way to rig up a dummy VSS to the EJ ECM. my EJ20H keeps going into limp mode when boost kicks in then i get a 4K RPM engine cut out after hitting boost a couple times. Turbo Gurus Pleas help me. And the reed switch in the stock cluster from my car is not working i would just like to make a dummy VSS to hook up to the ECM so it gets its pulses will run fine. Cheers R. Quote Link to comment Share on other sites More sharing options...
capn_r Posted August 22, 2011 Share Posted August 22, 2011 http://www.enginewiring.com/catalog.htm Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 22, 2011 Author Share Posted August 22, 2011 i don't have the money to buy something i want to make something solder some thing up with some simple electronics. Thanks though Cheers R. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted August 22, 2011 Share Posted August 22, 2011 (edited) The speed sensor is not something you can solder up with some electronics because it's output depends on vehicle speed - you have to use the speedo head or replace the cable with an electronic speed sending unit from a newer model that will create the proper sqaure-wave duty signal based on vehicle speed. It would probably be best to replace the speedo head or the whole gauge cluster. Simplest solution.... That simulator that's listed for the VW swaps..... I'm not sure how that would work because on the Subaru ECU's the idle speed doesn't return to 750 unless the car is stopped..... among other strange behaviour if you don't have a signal that actually translates to what the car is doing. Easier to just give it what it wants. GD Edited August 22, 2011 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
el_freddo Posted August 22, 2011 Share Posted August 22, 2011 That simulator that's listed for the VW swaps..... I'm not sure how that would work because on the Subaru ECU's the idle speed doesn't return to 750 unless the car is stopped..... among other strange behaviour if you don't have a signal that actually translates to what the car is doing. Easier to just give it what it wants. GD would a simple reed switch do the trick - something like this that is used for my cruise control: I've got the VSS from the stock L gauge plumbed in for my EJ - seems to go well but is not boosted with all of those cut out "features" you speak of subaruguru. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted August 22, 2011 Share Posted August 22, 2011 Yeah - one of those generic one's would likely work. GD Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 22, 2011 Author Share Posted August 22, 2011 ok i will make something work but as for the wire on the ECM the diagram says speed sensor 12+ but if i unhook the wire the engine idles up to 1000 RPM or so. reconect it and the engine idles down. do i just tap one wire from a reed swithc to the and the other side to ground? Cheers R. Quote Link to comment Share on other sites More sharing options...
suberdave Posted August 23, 2011 Share Posted August 23, 2011 you could go and get a speed sensor from the tranny of a newer EJ car, and wire it up to give the signal to the ECU. of course your spedo will not work at all. but you wont get limp mode... im not sure if you speedo is working now or not, this may not matter... Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 23, 2011 Author Share Posted August 23, 2011 Well i have the VSS from the 4eat i unscrewed it and used a cable type speedo i still have the VSS and i suppose i could live without a speedo for the show or i could go to the JY and pull the speedo out of a newer subaru that runs on the VSS and make it fit in my cluster. I saw a thread around here someplace edrach i think did it. Now its just the two wires one is a ground and one is a hot? IIRC i can get the speedo i need from 96 and newer right? Thanks for all the help everyone Cheers R. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted August 23, 2011 Share Posted August 23, 2011 ok i will make something work but as for the wire on the ECM the diagram says speed sensor 12+ but if i unhook the wire the engine idles up to 1000 RPM or so. reconect it and the engine idles down. You mean you have been putting 12v+ to the speed sensor terminal of the ECU? :-\ It takes a duty-signal. It wants a sqaure wave based on vehicle speed. That is availible from the the signal generator inside the speedo head. You just hook the (non black) wire from the generator to the ECU's terminal and the black wire to ground. GD Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 23, 2011 Author Share Posted August 23, 2011 ok thanks GD i will try that i am going to go the the JY today and snag me a speedo head from a newer legacy. On the 12v thing the pin out i have says it has 12v and when i test it it has 12v i have not hooked power to it its already got it. Cheers R. Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 24, 2011 Author Share Posted August 24, 2011 (edited) OK so i was able to get a cluster from a 96 legacy outback and i used the speedo and the tach from it with success the speedo works and the tach works so i made them fit in the ea housing. Now there is a plug for the speedo with a black and a white wire those went to the VSS on the trans then there is the ignition hot and the ground for the speedo both hooked up, The two other screws are marked SP the other C4 so i assumed the SP meant speed so i hooked up a wire and ran it to the wire i miss labeled as Speed sensor for the ECM and the speedo stopped working... So i called it a night and now looking at the Pinout again i realize i was looking at the wrong plug i had it connected to the (ISC Valve Closed) wire GAH so tomorrow i am going to try the right wire on the ECM and hope that it works. the speedo and tach work so this wire to the ECM is the last part to get done . If this looks right or wrong to anyone please let me know but it seems pretty simple. THANKS EVERYONE!!! Edited August 24, 2011 by subaruguru Quote Link to comment Share on other sites More sharing options...
el_freddo Posted August 24, 2011 Share Posted August 24, 2011 Subaruguru, could you also post up a couple of pics of the instrument cluster install, I'm intrigued! Cheers Bennie Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 24, 2011 Author Share Posted August 24, 2011 ill try to remember to get some shots today Cheers R. Quote Link to comment Share on other sites More sharing options...
subaruguru Posted August 25, 2011 Author Share Posted August 25, 2011 Got it all figured out and done she is ready for the show cant wait i will get some pics up asap in my build thread. Funny i hooked it up and it worked great then after a few hours of sitting i took it out and it started to cut out again..... this time i was just low on gas . Cheers and thanks for all the help. R. Quote Link to comment Share on other sites More sharing options...
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