Chris Wilson Posted June 1, 2010 Share Posted June 1, 2010 Why don't you try what to me is the obvious and free option and refit the old pump first, to see what happens? Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 1, 2010 Author Share Posted June 1, 2010 Why don't you try what to me is the obvious and free option and refit the old pump first, to see what happens? I don't have it any more.... I gave it to my friend who gave it to his friend... etc... Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 1, 2010 Share Posted June 1, 2010 Shame, because odds are it's the pump. Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 1, 2010 Author Share Posted June 1, 2010 Shame, because odds are it's the pump. yep, but normally the fuel pressure regulator should do its job even if the pump pressure is bigger... Today I'll change the fuel filter, I had it yesterday from Toyota, it's weird but I think it's smaller than the one I have on my supe... what do you think about the spark plugs that I linked ? they'll fit ? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 1, 2010 Share Posted June 1, 2010 Personally I wouldn't even consider copper cored plugs in a turbo engine. Precious metal cored ones may have the same heat grade as the copper ones, but their heat RANGE if things go a bit wrong is far greater before the pip falls off through heat or det. Unless you are saying it's hitting fuel cut through excess boost (what boost does it make???) it sounds like it's misfiring through low fuel pressure. A weak misfire will often show as a RICH mixture on the AFR gauge.. Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 1, 2010 Author Share Posted June 1, 2010 (edited) Personally I wouldn't even consider copper cored plugs in a turbo engine. Precious metal cored ones may have the same heat grade as the copper ones, but their heat RANGE if things go a bit wrong is far greater before the pip falls off through heat or det. Unless you are saying it's hitting fuel cut through excess boost (what boost does it make???) it sounds like it's misfiring through low fuel pressure. A weak misfire will often show as a RICH mixture on the AFR gauge.. So, yes I was thinking about a fuel cut, but the maximum boost that I get is 0.8, so it's not possible ( I got my apex boost gauge installed this weekend, so I guess it's a good measure...) and it cuts only on low boost (and sometimes the engine doesn't want to start) when I'm on high boost everything is fine (that's why I want to replace spark plugs, can you give me a reference of plugs that I should buy, I wanted denso IK20 at the beginning... and then guys told me about the NGK ones, and now I don't know what should I take...) Edited June 1, 2010 by dive_popo (see edit history) Quote Link to comment Share on other sites More sharing options...
shima60 Posted June 1, 2010 Share Posted June 1, 2010 i use ngk bkr7e gapped to .7 and no problems here cheap option to find out if its the plugs or not. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 1, 2010 Share Posted June 1, 2010 You could pull the return line off at the tank and measure the volume coming out in 30 seconds and double it. I'd want to see at LEAST 2 litres in 30 seconds, at the return. Quote Link to comment Share on other sites More sharing options...
fuldhat Posted June 1, 2010 Share Posted June 1, 2010 Buy a new pump.. they cost nothing. Would never buy such things used. Quote Link to comment Share on other sites More sharing options...
Multics Posted June 1, 2010 Share Posted June 1, 2010 A weak misfire will often show as a RICH mixture on the AFR gauge.. I think it's the other way around Chris. When misfiring there's no fuel being ignited so the wideband sensor picks up air (lean). There's too many things that can be wrong here. From coilpacks to incorrectly gapped plugs, second hand fuel pump to clogged fuel filter. It could simply be that the "new" pump is knackered and can't deliver enough juice hence the misfire and leaner AFR. Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 1, 2010 Author Share Posted June 1, 2010 Buy a new pump.. they cost nothing. Would never buy such things used. My friend had a breaking UK spec supra, and he told me to take everything that I'm interested in (for free), so I took the pump and the cruise control ...and the black carpet And as I haven't a big garage I gave him my old pump, and he gave it to his friend... Then I went back home ( abut 150 miles and everything was fine) and I wasn't driving slowly but about 100 to 120 mph... Then it stayed in the garage for a week, and when I took it again, I had this problem, in the beginning it wasn't all the time and now it happens more and more... About the fuel filter, I cant change it, it's raining now ! So I'll do it tomorrow, and as you said I think that my gap is too big ! about 2mm, on my Denso spark plugs, so they have to be replaced ! (they have about 15k miles, I guess, as I can't read my Japanese service book ) Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 2, 2010 Author Share Posted June 2, 2010 Hello guys, I have some news: My fuel filter was completely blocked ! I tried to blow in with my mouth and nothing wanted to pass ! I almost exploded my lungs when trying... I also opened the fuel tank, pumped all the fuel, then cleaned it, and put some new fuel... The engine runs perfect at the moment, I'll try to do some miles with it this evening and test when driving I bought some new plugs on the Ebay, so I'll change them on reception Thanks for your advices guys, I'll tell you more tomorrow Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 3, 2010 Author Share Posted June 3, 2010 I'm a little bit disappointed... So I don't have problems with starting the engine any more, but now on every hard accelerations the engine stops... It's allways when I'm getting on boost I think that it's spark plugs fault, so I'll wait to get plugs that I bought yesterday on Ebay Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted June 8, 2010 Share Posted June 8, 2010 FCD is needed Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 9, 2010 Author Share Posted June 9, 2010 So I changed the spark plugs, and I still have the same problem... Is the fuel pump ecu the same on Jap spec and uk spec ?? :/ Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 (edited) I think it's the other way around Chris. When misfiring there's no fuel being ignited so the wideband sensor picks up air (lean). I've had this argument before (not with you ) and I think Chris has it right. Let me see if I can find it. Edit - here it is: http://www.mkivsupra.net/vbb/showpost.php?p=2717642&postcount=13 "The sensor does not actually measure oxygen concentration, but rather the amount of oxygen needed to completely oxidize any remaining combustibles in the exhaust gas. " Edit again - hang on, is that even relevant?! I'm trying to fit this in around work and I'm not doing a good job of it! Edited June 9, 2010 by Ian C (see edit history) Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 OK I've stopped confusing myself. While an Oxygen sensor is called that, it's a misnomer as it measures the amount of oxygen needed to burn the remaining combustible material. High fuel content causes a higher voltage on the sensor, lower fuel content means the voltage is lower. The amount of oxygen is irrelevant, so an IGNITION misfire will chug unburnt fuel through the exhaust and cause a rich condition, as the sensor detects the fuel and increases the voltage signal. A FUEL misfire will cause a lean signal, as no fuel is there for the sensor to measure. Also the cylinder full of air will dilute the exhaust mix from the other cylinders, compounding the lean signal. I might actually read the thread now hah. Quote Link to comment Share on other sites More sharing options...
Multics Posted June 9, 2010 Share Posted June 9, 2010 I've had this argument before (not with you ) and I think Chris has it right. Let me see if I can find it. Edit - here it is: http://www.mkivsupra.net/vbb/showpost.php?p=2717642&postcount=13 "The sensor does not actually measure oxygen concentration, but rather the amount of oxygen needed to completely oxidize any remaining combustibles in the exhaust gas. " Edit again - hang on, is that even relevant?! I'm trying to fit this in around work and I'm not doing a good job of it! Very interesting but I'll stick to my theory I found this document on Bosch Wideband sensors, the last paragraph confirms what I believe is correct. http://www.tayloredge.com/reference/Chemistry/oxygensensor3.pdf Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 yep, but normally the fuel pressure regulator should do its job even if the pump pressure is bigger... What if the pump pressure is smaller? I once had a brand new UK spec pump that was almost DOA. It'd pressurise the system enough to start the engine, but after about 15 seconds it'd start to struggle as pressure droped off. Any tap on the throttle would stallit instantly. Again, try a different pump at least, even if you don't have the old one. get one of your generous freinds to let you pull theirs out and test it Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 Very interesting but I'll stick to my theory I found this document on Bosch Wideband sensors, the last paragraph confirms what I believe is correct. http://www.tayloredge.com/reference/Chemistry/oxygensensor3.pdf Well I'll certainly say that it being on Wikipedia doesn't necessarily make it true, I know that But then the same can be said about that PDF as well. I'm gonna look around some more as I'd like to find out exactly how a wideband sensor works and reacts to a misfire. Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 Right: http://researchinfo.bosch.com/content/language2/html/5354.htm "Lambda sensors measure residual oxygen in the exhaust gas." That's from Bosch themselves, and I believe they should know. So the wiki article is balls and I've been talking crap So a misfire should show up as an artificially lean signal as it measures loads of oxygen suddenly. I can relax now, confusion cleared up. Anyone fancy correcting the wiki article haha Quote Link to comment Share on other sites More sharing options...
dive_popo Posted June 9, 2010 Author Share Posted June 9, 2010 When the rain stops I'll verify all sensors, and I'll try to get somehow a Jap spec fuel pump (it's not easy to get parts for a supe in France...) I still have the problem with starting the engine (not all the time), it starts and stops I have to start and start it again... and then it works thanks guys ! Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 When the rain stops I'll verify all sensors, and I'll try to get somehow a Jap spec fuel pump (it's not easy to get parts for a supe in France...) I still have the problem with starting the engine (not all the time), it starts and stops I have to start and start it again... and then it works thanks guys ! Do what Chris said and see how much fuel is pumped out the return line. You can easily disconnect it from the pump cage or even in the engine bay, and pipe it into a plastic 2l pop bottle. Run the fuel system by bridging +B and FP in the diagnostics port and watch the fuel flow. See if you fill the bottle in about 30s and see if the flow is smooth and consistent. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 9, 2010 Share Posted June 9, 2010 I think it's the other way around Chris. When misfiring there's no fuel being ignited so the wideband sensor picks up air (lean). There's too many things that can be wrong here. From coilpacks to incorrectly gapped plugs, second hand fuel pump to clogged fuel filter. It could simply be that the "new" pump is knackered and can't deliver enough juice hence the misfire and leaner AFR. Sorry, I was talking rubbish, it is of course the other way around, a mixture so rich as to cause misfiring can show as lean on an AFR gauge due to the unburnt oxygen in the exhaust. Maybe I was tired, but it was more likely beer the night before, looking at the time stamp Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 9, 2010 Share Posted June 9, 2010 I don't have beer as an excuse, just wikipedia Quote Link to comment Share on other sites More sharing options...
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