geoffvalenti Posted April 16, 2004 Share Posted April 16, 2004 Hi one and all Does anyone actually know how the progressive PAS works on a VVTi tiptronic Supra? I'm not sure if its the same as the earlier ones. From what I can see there is a valve on the pump outlet with 2 pipes connected to the inlet manifold. Is this anything to do with it? Reason that I ask is that I've been playing around under the bonnet, cleaning a few bits etc. and now the steering seems a fair bit heavier than it was. I'm not complaining, (in fact I'm pleased) the very light steering was one thing I really didn't like about the Supra, it now feels much more like my old MR2 rather than a Yank I did pull all the fuses, but I've disconnected the battery before and it hasn't affected it. I've also (tried) to reset the TRAC ECU which may have something to do with it. I've tried the search button but to no avail. If anyone could point me in the direction of an explanation on how it works I'd be grateful really just for interests sake. Quote Link to comment Share on other sites More sharing options...
SimonB Posted April 16, 2004 Share Posted April 16, 2004 You haven't been playing with the kph/mph speed convertor I take it? Most just feed a converted signal in to the rest of the car, which means it thinks you are going slower than you are and gives too much assistance. The steering is FAR better when working correctly, but there must be loads of people who don't have it converted correctly. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted April 16, 2004 Author Share Posted April 16, 2004 Originally posted by SimonB You haven't been playing with the kph/mph speed convertor I take it? Most just feed a converted signal in to the rest of the car, which means it thinks you are going slower than you are and gives too much assistance. The steering is FAR better when working correctly, but there must be loads of people who don't have it converted correctly. I've got problems with the speed converter (it keeps switching the damn traction control on at low speed), but hopefully that will be sorted out as I've just ordered a decent one from Pete Betts at TRL, should have it by the end of next week It may be the speed converter, playing games with the steering but I haven't touched it today, and the steering only got heavier after I cleaned the cam cover and pulled the fuses. I tried to disconnect the TRAC control by removing the fuse, but that then stopped the fly by wire throttle, so I had to replace it Maybe that has somehow reset it to what it should be, its certainly a better weight steering, still got power assistance, its just not a 1 finger job anymore. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 16, 2004 Share Posted April 16, 2004 The valve you refer to gives an increased air supply to the engine (via the pipes you mention) when the steering is loaded. The valve senses pump output pressure and opens, and it then bypasses extra, metered air past the idle speed control valve. At least that's what it appears to do. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted April 16, 2004 Author Share Posted April 16, 2004 Originally posted by Chris Wilson The valve you refer to gives an increased air supply to the engine (via the pipes you mention) when the steering is loaded. The valve senses pump output pressure and opens, and it then bypasses extra, metered air past the idle speed control valve. At least that's what it appears to do. Thanks Chris Makes perfect sense, I should have worked that one out myself Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 17, 2004 Share Posted April 17, 2004 Actually it passes the throttle plate, not the idle speed control valve, but apart from that, that's what it does -Ian Quote Link to comment Share on other sites More sharing options...
Guest GRM Posted April 23, 2004 Share Posted April 23, 2004 This sounds promising for my light steering problem. I've pulled the fuses for the ECU's but that did nothing, I haven't tried the TRAC fuse yet. I assume you need to pull these fuses with the ignition on, otherwise whats the difference from just turning off the ignition? Should you wait a certain ammount of time before replacing ? I have a CARTEK CKDU speedo and delimiter chip, anyone got one of these that work (steering wise)? If not I'll just have to stump up the £100 for a new one from TRL! Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted April 23, 2004 Author Share Posted April 23, 2004 Originally posted by GRM I have a CARTEK CKDU speedo and delimiter chip, anyone got one of these that work (steering wise)? If not I'll just have to stump up the £100 for a new one from TRL! I've got a Cartek speed converter and thats the damn thing thats causing all the problems with the traction control and shift points. The speedo works OK but thats about it I'm getting a decent one from TRL but I think its trapped in the post (we haven't had any post for the last 2 days and thats unusual to say the least, so I think there must be problems at the sorting office) Quote Link to comment Share on other sites More sharing options...
SimonB Posted April 23, 2004 Share Posted April 23, 2004 Originally posted by GRM I've pulled the fuses for the ECU's but that did nothing, I haven't tried the TRAC fuse yet. I assume you need to pull these fuses with the ignition on, otherwise whats the difference from just turning off the ignition? The ECU gets power all the time from a permanent live as well as a switched feed from the ignition, pulling the fuse cuts off the permanent feed. Quote Link to comment Share on other sites More sharing options...
Guest GRM Posted April 26, 2004 Share Posted April 26, 2004 Thanks guys I've also had a reply from Thor Racing and I quote " I've lost count of the number of CarTek units I've removed from Supras :)". So anyone out there with steering or other problems, see what conversion chip you have fitted! Just so I don't get done for libel, I'm sure Cartek units work fine , just not in Supra's Quote Link to comment Share on other sites More sharing options...
nic_f Posted April 26, 2004 Share Posted April 26, 2004 Quick question, Where does one find the speed converter, I want to know what mine is now...... Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted April 26, 2004 Author Share Posted April 26, 2004 Originally posted by nic_f Quick question, Where does one find the speed converter, I want to know what mine is now...... It all depends what model Supra you've got. Most units fit behind the speedo, but some (VVTi Tiptronic for one) connect to the ECU in the passenger footwell. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 26, 2004 Share Posted April 26, 2004 Originally posted by nic_f Quick question, Where does one find the speed converter, I want to know what mine is now...... It appears the units fitted by JIC down right by the speed transducer on the LH side of the gearbox are the ones that give the most aggravation, as they divide by 5/8 the signal frm the sensor to ALL things that need to know propshaft RPM. Instead only the speedo itself should receive this divided signal, and these units are normally by the engine ECU or behind the dash, often near the speedo itself. It could be that the intermittent second turbo problems some are experiencing is caused by these incorrectly wired units (thanks Bill...), so it would be worth changing or checking if you suffer with this. Quote Link to comment Share on other sites More sharing options...
nic_f Posted April 27, 2004 Share Posted April 27, 2004 Originally posted by Chris Wilson It appears the units fitted by JIC down right by the speed transducer on the LH side of the gearbox are the ones that give the most aggravation, as they divide by 5/8 the signal frm the sensor to ALL things that need to know propshaft RPM. Instead only the speedo itself should receive this divided signal, and these units are normally by the engine ECU or behind the dash, often near the speedo itself. It could be that the intermittent second turbo problems some are experiencing is caused by these incorrectly wired units (thanks Bill...), so it would be worth changing or checking if you suffer with this. Chris, Thanks a lot for that, mine is a JIC car. I will go in search over the weekend. Nic Quote Link to comment Share on other sites More sharing options...
nic_f Posted April 27, 2004 Share Posted April 27, 2004 Originally posted by geoffvalenti It all depends what model Supra you've got. Most units fit behind the speedo, but some (VVTi Tiptronic for one) connect to the ECU in the passenger footwell. Thanks, I'll have a look. Quote Link to comment Share on other sites More sharing options...
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