Need4Speed Posted March 31, 2010 Share Posted March 31, 2010 I've had a search and found Big Num had a similar problem to this 5 years ago but the thread contained no result. The car has had new plugs, NGK - BCPR7ES - gap 0.7mm, coil-pack connectors overhauled etc. and now it has a hesitation at low revs except with very light throttle. Once the boost is up, and particularly on the second turbo it's revving cleanly as it should. The symptoms are hesitancy and the odd pop from the exhaust. Is this a low-revs fueling issue and if so what could be causing it? I don't have any afr measuring kit. There are no stored error codes. Quote Link to comment Share on other sites More sharing options...
shima60 Posted March 31, 2010 Share Posted March 31, 2010 get yourself on a dyno with a a/f and check the fueling thats a good place to start. also check for boost leaks and things like that. i bought an a/f gauge a year or so back. imo best thing you can buy before you start playing with the car Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted March 31, 2010 Author Share Posted March 31, 2010 get yourself on a dyno with a a/f and check the fueling thats a good place to start. also check for boost leaks and things like that. There are no leaks. It pulls strongly to 1.1 bar, or 1.2 if I set at 1.2. The plug colours are fine. Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 31, 2010 Share Posted March 31, 2010 Sounds like closed loop overfuelling caused by a manky oxygen sensor. There is a tech article that shows you how to check your fuelling under these conditions using a multimeter on the diagnostics port -Ian Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted March 31, 2010 Author Share Posted March 31, 2010 Thanks Ian. Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted April 1, 2010 Author Share Posted April 1, 2010 I measured the voltage as per Ian's guide and it's jumping from 0.12v to 0.75v so I guess it's proper f**ked. Anybody got a part number for the oxygen sensor (UK Car)? Quote Link to comment Share on other sites More sharing options...
Nic Posted April 1, 2010 Share Posted April 1, 2010 There are 2 x O2 sensors on the UK TT, part numbers below. 89465-19595 Oxygen Sensor - Rear 89465-19605 Oxygen Sensor - Front Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted April 1, 2010 Author Share Posted April 1, 2010 There are 2 x O2 sensors on the UK TT, part numbers below. 89465-19595 Oxygen Sensor - Rear 89465-19605 Oxygen Sensor - Front Thanks Nic, mine's only got the front one. A dodgy decat/recat in its history and the second sensor's no longer there! Quote Link to comment Share on other sites More sharing options...
Nic Posted April 1, 2010 Share Posted April 1, 2010 I'm not very familiar with the UK spec Supra, is 2nd sensor after the 1st cat? I'm just wondering if only running the first sensor would effect the ECU and be causing some of the symptoms you are having. Quote Link to comment Share on other sites More sharing options...
SteveC Posted April 1, 2010 Share Posted April 1, 2010 The 2nd O2 sensor is normally mounted in the 2nd cat. It should really be put back into a 2nd decat pipe, apparently. Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted April 1, 2010 Author Share Posted April 1, 2010 I'm not very familiar with the UK spec Supra, is 2nd sensor after the 1st cat? I'm just wondering if only running the first sensor would effect the ECU and be causing some of the symptoms you are having. Nic, I'm going to put the 2nd sensor back in as, if nothing else, it will remove the permanent error code 27. Here's a diagram of where it is. Quote Link to comment Share on other sites More sharing options...
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