Homer Posted February 8, 2004 Share Posted February 8, 2004 I've had the supra about a month now (and love every minute of it ), but there’s an annoying problem... Occasionally under acceleration the 2nd turbo doesn't seem to kick in. It will be accelerating fine up to about 4k rpm, then when you expect to have the 2nd turbo come online it just doesn’t happen (The boost gauge shows 0 bar). This seems to be pretty random, most of the time the car runs fine and gets 0.7 bar, so I’m really not sure what could be causing this. I've checked all the hoses and they all look fine. Any suggestions or advice guys? Cheers Quote Link to comment Share on other sites More sharing options...
osso Posted February 8, 2004 Share Posted February 8, 2004 Are you saying that from 0 to 3800 rpm the 1st turbo is boosting normally to around 0.7 to 0.8 bar then beyond 3800 rpm you're loosing all boost back to 0 bar? if thats the case then the exhaust side on the 2nd turbo is probably shagged. try putting it into TTC mode very easy to do, if you dont get any boost at all in TTC mode, then the 2nd turbo is definitely shagged sorry mate. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 8, 2004 Author Share Posted February 8, 2004 Sorry, I didn't explain too well... Just took the car out to check what’s happening: On normal driving the car picks up and makes 0.55 bar (not 0.7 as I said before, I didn't pay too much attention to the boost gauge until today!). The acceleration is smooth and the car makes all the right sounds. The boost gauge shows there is boost being made from about 2500 rpm. Occasionally (normally off the lights or pulling away from roundabouts), it feels as though there is no boost. As the engine goes through the rev range, the boost gauge goes from ~600mmHg then stops when it gets to 0 bar (in 1st or 2nd gear this is normally around 4000rpm). If I then change up or take my foot off and accelerate again the turbo comes to life. This is going to sound stupid I’m sure but what’s TTC?? Cheers Quote Link to comment Share on other sites More sharing options...
Soonto_HAS_soop Posted February 8, 2004 Share Posted February 8, 2004 True Twin Conversion Ben.. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 On the commute to work today there seems to be a new problem developing!! Now, when the car gets to full boost (about 0.5 bar on the gauge) it stutters while continuing to accelerate. The feeling is like it can't get enough fuel. If I accelerate at say quarter throttle and don’t hit full boost it’s fine, I'm pretty certain this is turbo/fuel related The only mods on the car are a dump value, exhaust (still has both cats) and an air filter so I can't see that it is fuel cut.... Dude, this is the same car I got from Paul E a few weeks ago so figured you might have an idea? Is there anything obvious to check before I book into Toyota? Quote Link to comment Share on other sites More sharing options...
dude Posted February 10, 2004 Share Posted February 10, 2004 Originally posted by Loid On the commute to work today there seems to be a new problem developing!! Now, when the car gets to full boost (about 0.5 bar on the gauge) it stutters while continuing to accelerate. The feeling is like it can't get enough fuel. If I accelerate at say quarter throttle and don’t hit full boost it’s fine, I'm pretty certain this is turbo/fuel related The only mods on the car are a dump value, exhaust (still has both cats) and an air filter so I can't see that it is fuel cut.... Dude, this is the same car I got from Paul E a few weeks ago so figured you might have an idea? Is there anything obvious to check before I book into Toyota? For a start dont book into Toyota , they wont know where to start , let me get home tonite and think this thru , im freezing me nads off in the office at work and my pinkies are going blue !!!! Dude:flame Dev Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 Thanks Dude, much appreciated Quote Link to comment Share on other sites More sharing options...
Wez Posted February 10, 2004 Share Posted February 10, 2004 0.5 Bar sounds too low. Does the boost go down then up again at approx 3800rpm? Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 Wez, No, there is boost from the 1st turbo. According to the boost gauge it is pretty stable once the pressure is up (even though it stutters). It picks up from about 2500, increases to 0.5 bar and stays there until I take my foot off the gas. Quote Link to comment Share on other sites More sharing options...
Wez Posted February 10, 2004 Share Posted February 10, 2004 ok, doesn`t sound like second turbo is coming online at all, when does the car start to stutter? Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 I'm pretty sure the 2nd turbo is working as theres still a strong pull around 4000 rpm. The stuttering only starts when it hits full boost (normally about 3600 rpm in 3rd or 4th). Quote Link to comment Share on other sites More sharing options...
Wez Posted February 10, 2004 Share Posted February 10, 2004 If everything is working correctly you should see something like this :- 0000 - 3500 rpm approx 0.6 Bar 3500 - 3800 rpm boost drop and raise again 3800 - 7000 rpm approx 0.8 Bar Sounds like you are getting 0.5 Bar all the way. As for the stuttering it could be many things, fuel starvation, ignition problem, bad plugs, dodgy turbo etc What boost gauge do you have and where is it plumbed in? Quote Link to comment Share on other sites More sharing options...
Dragonball Posted February 10, 2004 Share Posted February 10, 2004 HI m8 - Sounds like it could be the plugs or purhaps coil pack- the second turbo is def there! Dude will no doubt be back and give a couple of options - but this one pulled like a train so shouldn't be too much of a problem Just a quick one - have you been down to Matts to sort the dodgy speedo converter? - thye new one is waiting for you! Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 Wez, thats for response, I've never noticed boost drop down between the 1st and 2nd turbo but like I aid I didn't pay much attention to the gauge until the last 2 days!! Its a HKS gauge but have noi idea where's its wired in !! Paul, the faulty converter is still i the car as I haven't had time to speak to Matt yet. I'll give him a call tomorrow... You're right though, the car still pulls very hard despite occaisonal loss of boost and the stuttering. I expect dude will have some advice as soon as he's warmed up Quote Link to comment Share on other sites More sharing options...
dude Posted February 10, 2004 Share Posted February 10, 2004 I would defo go for plugs first , you dont need to put iridiums in you can throw some NGK's in , they will be fine for a few 1000 miles and to diagnose the problem , Matt will prob do it for you while you are there . Dude:flame Dev Quote Link to comment Share on other sites More sharing options...
Homer Posted February 10, 2004 Author Share Posted February 10, 2004 Thanks mate Just spotted Paul R's post Will speak to Matt tomorrow to see what plugs to get Cheers Quote Link to comment Share on other sites More sharing options...
chriseltham Posted February 10, 2004 Share Posted February 10, 2004 I had this stuttering problem, thought it was fuel cut at first but Pete at Thor diagnosed it as the wrong grade plugs, put a new set in and it is a hell of a lot smoother, as the un on the rollers showed, the stuttering comes very rarely now and it is mostly smooth running Quote Link to comment Share on other sites More sharing options...
Homer Posted February 14, 2004 Author Share Posted February 14, 2004 Everything’s okay!! It turned out to be dodgy plugs - the iridium ones were a bit knackered and had a gap of about 2mm!! Replaced them with NGK's and no more spluttering. The low boost was not actually low boost but a split pipe to the boost gauge, been replaced and now see 0.7 bar again. Thanks to everyone for the suggestions and especially Matt for sorting out the FCD and de-limiter today (and for putting up with all my questions) - what a nice bloke Quote Link to comment Share on other sites More sharing options...
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