JohnA Posted August 1, 2005 Share Posted August 1, 2005 http://www.max-boost.co.uk/stuff/AVFC_connections.gif Anyone know what's the story with these two grounds? I would have thought that one of them is totally redundant, in fact that both of them could be omitted and another ground used altogether. Why are they making such a fuss about two ground signals next to each other? Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 1, 2005 Share Posted August 1, 2005 Maybe its common to see a few fractions of a volt difference between the ECU ground and wherever you usually mount the S-AFC. I've seen gounds that had sufficient resistance to drop 0.1V when I was wiring in my foglamp. Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 1, 2005 Author Share Posted August 1, 2005 I understand this, but tapping a few millimetres down the same wire won't produce even a thousandth of a volt difference, WTF, this isn't exactly a resistor wire taken from a heater, is it? Or is it that the black wire is meant to be on a different ground in the vicinity (say a self-tapping screw)? If so, why don't they say so? I don't understand this sort of twin-ground setup that they ask for (in their diagram at least). For my Thor FCD I used a different ground altogether (didn't want to sift through the frikin loom and hack a wire I can barely reach) Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 1, 2005 Share Posted August 1, 2005 At a rough guess, I'd say the diagram wasn't exactly "to scale". Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 1, 2005 Author Share Posted August 1, 2005 Well I'm thinking of getting an AFC-2 so that I can lean out parts of the rev range that are abnormally rich from the factory. But if their instructions are vague and questionable, I'm not so sure. ...And what's the story with tables showing the non-VVTi 2JZGTE as using MAP for fuelling? That's taken from the US Apexi, where the models were like UKSpec. Am I missing something here, or are the instructions slap-dash and happy to point you towards their local 'dealer'? Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 1, 2005 Author Share Posted August 1, 2005 Curiouser and curiouser.... As I am about to email these people in the States to see what the hell you're supposed to enter in the 'MAF' section (neither the UK nor the US 2JGTEs use MAP for fuelling, right? Well their tables say otherwise)... ...I find this clarification on my double ground question pages 3 & 4 looks like the diagram IS to scale. They clearly state NOT to use any other vehicle grounds, and not group the two grounds together either. No, connect them 1cm apart, brown earth closer to the ECU (or else!) I really don't get the reason behind this. There is not much space on the loom for two such splices either, it's very tight. ...so what gives then? Quote Link to comment Share on other sites More sharing options...
paul mac Posted August 1, 2005 Share Posted August 1, 2005 Curiouser and curiouser.... I really don't get the reason behind this. There is not much space on the loom for two such splices either, it's very tight. ...so what gives then? having recently installed one of these i have to admit i was baffled about this set up of the ground wires and having worked in a maintenance background all my life know a bit about wiring, i however decided some jap egg head had'nt done it just to make my life arkward and dutyfully connected as recomended and all works fine, i did consider asking a boffin at work (nuke power station) what it was all about but after half a second went off the idea as he'd probably start about the theory of relativety, as for the set up i dont think you can do justice to any type of fuel controller/ecu by just screaming up and down the bypass untill it "feels right" and left the good people at Thor to worry all about that on the dyno (cost £150 set up for safc and itc, money very well spent) Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 1, 2005 Share Posted August 1, 2005 Yeah, I spoke to Chis tonight and he told me that the wires should be 1cm apart. Bonkers. isn't it? No idea what the reason might be. Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 2, 2005 Author Share Posted August 2, 2005 Digsy, can you also ask him what a UKSpec should enter as the AFM? Their tables look all wrong to me. Quote Link to comment Share on other sites More sharing options...
Digsy Posted August 2, 2005 Share Posted August 2, 2005 Reply from Ian. I've no idea what AFM setting the AFC should use, the lookup tables in the docco only mention the J-Spec pressure sensor... However the E-Manage uses Toyota HW-4 so if the AFC has got that setting then I'd try that. Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 2, 2005 Author Share Posted August 2, 2005 Most Skylines have "HW4" setting. This whole thing feels very hackish to me, the 'adjusted' values will be all over the place if the wrong sensor is chosen. Not sure if the unadjusted values will be also affected, either.... Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 2, 2005 Author Share Posted August 2, 2005 They have a 'clarification' document on the US site, revising the setting for the US MAF (should be same as the UKSpec I'd think) to "HW12" I wonder if there are UKSpec owners running S-AFC without knowing about this... Quote Link to comment Share on other sites More sharing options...
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