GRIM Posted June 9, 2009 Share Posted June 9, 2009 Hello guys today I was driving around and just noticed that my AFR shows !!! 9 !!! (at full throttle) I have TOMEI AFR gauge(with it's own sensor) so lowest it has is 9 and pointer just falls to it It Idles at 14.2 I checked for boost leaks (visualy only) I checked the piping and bov(HKS SQV(first version)) everything looks normal (i checked connections too) i don't see any smoke at least in rear view mirror (no smoke even while free revving) no buck at all and no scooby sound the only thing i feel is that the car accelerates not as good till 4K rpm's (turbo's are OK) (maybe it's me? ) and at 4K rpm i feel like a punch and it accelerates like crazy I changed plugs to NGK 3330(BCPR7ES)(left gap stock) oh and sometimes i see that AFR gauge pointer jumps (at free revving, sometimes while acceleration, never at idle) should i do diagnostics? have any advice? what should I check? here are TOMEI docs: http://img14.imageshack.us/img14/7416/img754.jpg http://img14.imageshack.us/img14/7637/img756.jpg it has its own sensor, which is plugged in stock location and stock harness is plugged to it as well as a gauge Oh and btw here are the specs of my car: '97 JDM TT 6 speed MINE'S ECU TRD Ver.S catback TRD air filter in stock airbox both cats in place stock boost (0.7bar) no AFC and no boost controller Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted June 9, 2009 Share Posted June 9, 2009 Get the AFR's checked at a garage to eliminate your gauge being faulty. Quote Link to comment Share on other sites More sharing options...
Alex Posted June 9, 2009 Share Posted June 9, 2009 Stock cars are massively rich to protect the engine... Up the boost to use up the extra. Or get an e-manage to trim it back. On re-Reading the Mines ECU is also aggressive on timing and fueling... Normal Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 9, 2009 Author Share Posted June 9, 2009 as I have read here: http://www.mkivsupra.net/vbb/showthread.php?t=35940 my A/F ratio should be close to 11.7 at full throttle so isn't 9 crazy rich? Quote Link to comment Share on other sites More sharing options...
Homer Posted June 9, 2009 Share Posted June 9, 2009 The mines ECU does screw with some of the fueling AFAIK. At 0.7 bar you're running less than stock boost (which is 0.76 bar), so this might be part of the cause. Most mines ECu cars coming from japan are running at least 1 bar so it could be that the piggyback ecu is messing up your fueling. 9.0 AFR is very rich, but the stock supra does tend to run into the 10's even at higher than stock boost levels. It's normal for the AFR gauge to 'float' at idle, it should swing between 14.0 and 15.5, this is how the engine manages fueling. Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 9, 2009 Author Share Posted June 9, 2009 (edited) at 9.0 afr shouldn't car smoke? also spark plugs should be smoked, right? here are my spark plugs, when I removed em couple days ago http://img43.imageshack.us/img43/452/img712.th.jpg boost is about 0.7 I cant really tell if it's 0.76 (It's an analog gauge) also at idle AFR is very stable allways at 14.2 but when I'm driving it the pointer sometimes jumps up&down Edited June 9, 2009 by GRIM (see edit history) Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted June 10, 2009 Share Posted June 10, 2009 I have a mines ECU in mine. I have an RR prinitout at home with all the AFR's on it throughout the run. I'll have a gander and let you know what the figures are. Quote Link to comment Share on other sites More sharing options...
Homer Posted June 10, 2009 Share Posted June 10, 2009 at 9.0 afr shouldn't car smoke? Not in my experience, but your gauge or sensor might be out of acurate range, many of the cheaper ones (and I mean mainbrand japanese ones) don't read well below 10.0 so it might just be a poor reading. The plugs look good to me so no sign of massive overfuel. Can you clarify what you mean by the pointer jumping up and down? Is it a dramatic one or just a steady fluctuation? Quote Link to comment Share on other sites More sharing options...
Terminator Posted June 10, 2009 Share Posted June 10, 2009 It sounds as if you have an undamped gauge. As far as measuring AFR goes an analog gauge is probably best avoided. I would try to get someone with a quality AFR system to check your car for you. If the gauge is telling lies at one end of the scale I would throw it away. Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 11, 2009 Author Share Posted June 11, 2009 Can you clarify what you mean by the pointer jumping up and down? Is it a dramatic one or just a steady fluctuation? when i open the throttle the pointer of the gauge starts to play, it's going to 10's than returns to 14 and so on I can take a video if it helps Quote Link to comment Share on other sites More sharing options...
Alex Posted June 11, 2009 Share Posted June 11, 2009 as I have read here: http://www.mkivsupra.net/vbb/showthread.php?t=35940 my A/F ratio should be close to 11.7 at full throttle so isn't 9 crazy rich? 11.7-11.3 is the ideal for a normal car. TBH I'd be happy with something that drops into the high 10's a very high rpm/boost. 12.5 is maximum power minimum life (race car). Toyota and other OEM's have to set their cars up very safe, they have to assume the owner is an idiot. Idiots fill up on 95ron sh1t fuel and then nail the throttle. To protect the engine they add more fuel than is strictly necessary, you can then mop up the extra (knowing you're not an idiot and use the right fuel all the time) by upping the boost carefully. Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 23, 2009 Author Share Posted June 23, 2009 (edited) HeY Guys now I'm going to buy WB and need some advice should I connect new WB to the ecu or it's better to get a stock O2 sensor ? (now my wideband sensor is connected instead of stock O2) also my car is JDM and it uses 3 wire O2, where can I get one? Edited June 23, 2009 by GRIM (see edit history) Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 26, 2009 Author Share Posted June 26, 2009 anyone? Quote Link to comment Share on other sites More sharing options...
Guest mvaterjr Posted June 28, 2009 Share Posted June 28, 2009 get a WB and make sure it is installed around 14 inches behind the turbo. your better off replacing your o2 sensors with aftermarket sensors than staying with stock. get a WB, and look at Innovative to replace your stock o2's. Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 29, 2009 Share Posted June 29, 2009 your better off replacing your o2 sensors with aftermarket sensors than staying with stock. Because...? Quote Link to comment Share on other sites More sharing options...
heckler Posted June 29, 2009 Share Posted June 29, 2009 HeY Guys now I'm going to buy WB and need some advice should I connect new WB to the ecu or it's better to get a stock O2 sensor ? (now my wideband sensor is connected instead of stock O2) also my car is JDM and it uses 3 wire O2, where can I get one? stock O2 sensor for stock ECU, WB should be independent of the ECU Quote Link to comment Share on other sites More sharing options...
GRIM Posted June 29, 2009 Author Share Posted June 29, 2009 (edited) Thanks guys for your comments I've just checked my sensor and wiring, I thought my wiring is for 3 wire sensor but I was wrong it has 4 wires but 1 is cutted 3 wires from wideband go to my ecu so I need stock O2 sensor can anyone tell me where can I get one? (JDM '97 Supra TT 6sp. Non-VVTi) Oh and btw will the sensor of US/UK TT work ? Edited June 30, 2009 by GRIM (see edit history) Quote Link to comment Share on other sites More sharing options...
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