Graham Rudd Posted March 12, 2002 Share Posted March 12, 2002 If I plant the throttle from quite slow speeds, usually from rolling along in second gear, I seem to get some hesitation as the second turbo kicks in. Its best described as a sort of juddering around the point the car should really take off, as if it wants to go but can't quite manage it. The effect feels pretty much as if you were pumping your foot up and down on the accelerator very rapidly (quicker than you could actually do it in reality). It'll do this for maybe half a second, then suddenly take off as if nothing is wrong. It doesn't always do this, but when it does it feels pretty bad. Does the supra have a throttle body position sensor? If so could it be that mine is a bit iffy? My limited understanding of the subject seems to suggest to me that maybe the fuel isn't being delivered to cope with the sudden intake of air. On the other hand I could be talking complete arse. One thing of note is that I've got a Blitz ECU, could this be the culprit? Cheers Graham Quote Link to comment Share on other sites More sharing options...
GavinL Posted March 12, 2002 Share Posted March 12, 2002 Hi... Do you have the stock fuel regulator? I have had this problem with a faulty aftermarket jobbie. Quote Link to comment Share on other sites More sharing options...
Lee Hockley Posted March 12, 2002 Share Posted March 12, 2002 I have a similar problem. Do you have a boost gauge ? If so, what is the reading ? Quote Link to comment Share on other sites More sharing options...
AJI Posted March 12, 2002 Share Posted March 12, 2002 Are you sure it isn't the traction control kicking in? That would give the same type of sensation you are talking about. Other than that it sounds pretty bad. Quote Link to comment Share on other sites More sharing options...
Graham Rudd Posted March 12, 2002 Author Share Posted March 12, 2002 Gavin, I've no idea if I have the stock fuel regulator or not. Any quick and easy way to tell? Lee, I have a boost gauge, but it doesn't seem to be boost related, more to do going from practically no load on the engine, to giving a bootful. Doesn't happen at speed. AJI, definately not traction control, stock or RL. I don't like the "sounds pretty bad." bit! Graham Quote Link to comment Share on other sites More sharing options...
GavinL Posted March 12, 2002 Share Posted March 12, 2002 Quote: from Graham Rudd on 1:07 pm on Mar. 12, 2002[br]Gavin, I've no idea if I have the stock fuel regulator or not. Any quick and easy way to tell? Graham Not easy to explain, do you have a digi camera? Quote Link to comment Share on other sites More sharing options...
Graham Rudd Posted March 12, 2002 Author Share Posted March 12, 2002 Not easy to explain, do you have a digi camera? Yep, whereabouts shall I point the camera? (Edited by Graham Rudd at 1:59 pm on Mar. 12, 2002) Quote Link to comment Share on other sites More sharing options...
Lee Hockley Posted March 12, 2002 Share Posted March 12, 2002 Quote: from Graham Rudd on 1:07 pm on Mar. 12, 2002[br]Lee, I have a boost gauge, but it doesn't seem to be boost related, more to do going from practically no load on the engine, to giving a bootful. Doesn't happen at speed. Ok. Graham it might not be the same problem as mine but I will explain the symptoms that occur with me, just incase. I can be in rolling start with low gears in 2nd or 3rd with low revs. Then after flooring the accelerator the boost raises too quickly hitting the fuel cut limit, approx 1 bar. Sometimes border line which gives a stuttering in power. Sometimes violent if pushed too far and the worst being when the fuel is cut completly. Quote Link to comment Share on other sites More sharing options...
Graham Rudd Posted March 12, 2002 Author Share Posted March 12, 2002 I can be in rolling start with low gears in 2nd or 3rd with low revs. Then after flooring the accelerator the boost raises too quickly hitting the fuel cut limit, approx 1 bar. Sometimes border line which gives a stuttering in power. Sometimes violent if pushed too far and the worst being when the fuel is cut completly. Ahh.. definately not that then, I don't have a fuel cut limit. In fact I was boosting to 1.9 bar with no problem (bar the obvious) when one of my hoses came off. Graham Quote Link to comment Share on other sites More sharing options...
GavinL Posted March 12, 2002 Share Posted March 12, 2002 Quote: from Graham Rudd on 1:29 pm on Mar. 12, 2002[br]Not easy to explain, do you have a digi camera? Yep, whereabouts shall I point the camera? Just too the right of the cam cover, if you include the traction control badge on the throttle that should do it. Quote Link to comment Share on other sites More sharing options...
Alex Posted March 12, 2002 Share Posted March 12, 2002 Err 1.9 bar on a Blitz 100octane ECU...anyone else notice whats wrong.... Blitz ECU has a race map... 1. Do you have 440CC injectors? 2. What fuel do you use? Sounds like the map is not suited to twin sequentials as it doesn't flow enough fuel to get the second turbo going till you've got to higher revs Quote Link to comment Share on other sites More sharing options...
Peter Connelly Posted March 12, 2002 Share Posted March 12, 2002 The symptoms you describe sound similar to the problem I had not too long ago. It ended up being several loose piping (NOT disconnected), in the engine bay... Peter Quote Link to comment Share on other sites More sharing options...
Graham Rudd Posted March 12, 2002 Author Share Posted March 12, 2002 Alex, I use SUL + octane booster, 1.9 was down to a hose coming off. I *think* the injectors are stock 440cc, not certain. Gavin, here is a link to the pics I've just taken. http://www.matrixcity.org/supra_bay.html Peter, thanks I'll check all the hoses I can get at tonight. Graham Quote Link to comment Share on other sites More sharing options...
Peter Connelly Posted March 12, 2002 Share Posted March 12, 2002 Graham, you might need to disconnect the large pipe coming from the turbos (the one that goes across your air filter) to get at the smaller ones around the wastegate area! Good luck. Hope it's nothing serious! Peter Quote Link to comment Share on other sites More sharing options...
Graham Rudd Posted March 13, 2002 Author Share Posted March 13, 2002 Is the fuel regulator visible in any of the pics I posted a link to? Or is there a giveaway that might tell me if I've got a stock fuel regulator or not? Thanks Graham Quote Link to comment Share on other sites More sharing options...
badtoy Posted March 14, 2002 Share Posted March 14, 2002 gap your plugs down to 0.28 and have a look if it helps, if it not helps check your throttle position sensor #1 and #2 like descripted in the toyota repair manual. at many times timing retard or missfireing are a result of a bad adjusted throttle position sensor. sometimes the efi main or efi #2 relays goes bad, result no jump from 9v to 12v. my relays had to much resistant infact of this I had never 12 v power at my pump. check the toyota repair manual how to check the relays. hope it helps, if not let me know. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 14, 2002 Share Posted March 14, 2002 Quote: from Peter Connelly on 2:22 pm on Mar. 12, 2002[br]The symptoms you describe sound similar to the problem I had not too long ago. It ended up being several loose piping (NOT disconnected), in the engine bay... Peter I take it it is still OK then Pete? I could tell from your face you weren't convinced a few small leaks would cause the loss of the 2nd turbo, until the road test :-) Sounds like Grahams trouble could be the same, time for him to sample a decent but cheap meal ehhh ? Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 14, 2002 Share Posted March 14, 2002 Or perhaps some mud to bung up the holes? On a more serious note, juddering may be caused by the 2nd turbo's exhaust gas bypass valve not opening quickly, because of a vacuum pipe leak. This is reasonably bad news, because the intake air control valve has to open after the EGBV. If it opens before, boosted air feeds back down to #2 turbo and spins it backwards, losing you power quite severely (0.3-0.5bar max boost). That's not the end of the story, though, because when the EGBV finally wheezes open, the exhaust gas flows through #2 turbo and hammers it back to spinning in the correct direction - so you have boosted air trying to keep it spinning one way, and the exhaust gas trying to reverse it. The exhaust gas will win eventually, but imagine the strain it puts the vanes and shaft of #2 under! -Ian -Ian Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 14, 2002 Share Posted March 14, 2002 That's -Ian In case you didn't get it the first two times (dunno what happened there) Also supporting the theory of a problem with the EGBV, #1 turbo will boost to 0.7bar, so if you see less than this it is going somewhere rather than not being generated in the first place - i.e. back down #2's compressor. This could still be a leak between the turbo's and the intake manifold, of course, just giving you something concrete to check out. -Ian Quote Link to comment Share on other sites More sharing options...
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