Ian C Posted May 20, 2002 Share Posted May 20, 2002 I've fitting 550cc injectors, the associated resistor pack, and the UK spec fuel pump. The car took ages to start (panic) but it did (relief). Then it hunted (the battery had been disconnected, so I wasn't too worried), nearly died, caught it, and died. Now it displays two traits - One, it will start, run great, smooth, etc. at about 800rpm until it starts to hunt for a lower idle. It then drops the revs a lot until it cuts out (takes about 4-5 seconds). Two, if I attempt to open the throttle at all, it dies in about 1 second flat. I've tried leaning it off up to -50% with the Apexi unit, but I suspect that there is f-all it can do at idle. Any clues what this sounds like? The injectors must be working OK as it will briefly idle. The fuel pump is supplying fuel as it will start and catch instantly every time. Is it simply now running far too rich? -Ian Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted May 20, 2002 Share Posted May 20, 2002 It will be to rich, I've got my S-AFC leaned off about 25% at 1000rpm on low throttle setting of 16% and that ticks over nice. Without this it wouldn't idle properly, kept on cutting out. With these 550cc injectors fitted you really do need to get a wide band afr on there to set it up as it runs wayyyyyy to rich on full throttle. Or of course one of my mappable ECU's which will be out Very soon. Anyway, sounds like something else is up with it if you've taken out 50%. Quote Link to comment Share on other sites More sharing options...
Alex Posted May 20, 2002 Share Posted May 20, 2002 We know its rich but as we know the 550's flow 25% more than the 440's. so leaning it off by 25% should work...but everytime you play with the throttle is cuts out almost instantly....almost as if you've actually put a bung in the intake manifold to stall it! Having an AFR gauge souldn't be necessary as we know the system has gone up 25%... What Ian hasn't mentioned is his FSE valve...I wonder if its to blame? Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted May 20, 2002 Share Posted May 20, 2002 I wouldn't just work on the assumption of leaning off 25% across the board, you *must* get an WB AFR on there and tune it, otherwise it runs way to rich, I found this out myself, it was off the scale!! I had an FSE valve go on me, that was just cutting out under boost, I stuck the std one back on and it was fine again. I got a new replacement one sent to me, its sitting here brand new in the box if anyone wants it? Bit hard to say what the problem is without seeing the car in the flesh. Quote Link to comment Share on other sites More sharing options...
Alex Posted May 20, 2002 Share Posted May 20, 2002 We only need to get it running to get it to Chris W, we were supposed to drive up there tonight but it's been scuppered, getting it to run even poorly would be a result. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted May 20, 2002 Share Posted May 20, 2002 Hasn't Chris got any ideas? Was it alright before you changed the injectors? Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted May 20, 2002 Share Posted May 20, 2002 Do the plugs indicate that the car is running rich ? Quote Link to comment Share on other sites More sharing options...
Alex Posted May 20, 2002 Share Posted May 20, 2002 Martin, Its only been fired up fo 40secs in all...would it already show on the plugs? Paul, I would guess Ian is on the phone to him now...hence his lack of replies in the last few minutes. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 20, 2002 Author Share Posted May 20, 2002 Glad to see Alex was assisting while I was asleep The car was running fine before the upgrade. Chris Wilson's first thought is low line pressure, which may tally with Mr. Whiffin's suspicions of the FSE valve. I haven't got a stock fuel pressure regulator, but I will get a new one from Toyota if I have to. It's been running a tad rich since the earthing fault anyway, as the Apexi's memory was wiped due to the electrical freakery. I set it up on the safe side of rich, (limiting the boost to 0.8bar with the old right foot) and it's mpg has dropped to 17-19 rather than the 21-25 previously enjoyed. Therefore, the exhaust interior is black and the plugs probably will be as well. To allay other's fears, the plan was to limp the car to CW's overfuelling by x amount and staying off boost to avoid any potential disasters. CW has a top banana wide band afr jobbie and the exhaust pipe already has a socket for the probe. We weren't just going to guess the fuelling - I have one dead engine so far thanks to an unnamed tuning shop and their empty reassurances, I don't want another strictly due to my own fault Thanks for the help so far, keep it coming. I'm recovering from my deep blue funk. At least the injectors work - the wiring was my biggest concern... Er, it wouldn't be the wiring, would it? Making the injectors behave oddly? Surely not - it idles ok while it's not trying to hunt... -Ian Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted May 20, 2002 Share Posted May 20, 2002 Possibly, if they are not showing lots of sooty deposit then whatever colour they are may indicate something. Only thing is, just thinking about it, I would guess the plugs are not so new. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 20, 2002 Author Share Posted May 20, 2002 Hmmm - about 3000 miles old. New engine, remember...? -Ian Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 20, 2002 Author Share Posted May 20, 2002 Sorry, Martin, I've re-read that and it sounds pissy Didn't mean to come over all stroppy. The plugs were installed new as part of the engine swap, so they are about 3000 miles old now. But it's been overfuelling a bit for about 1000 of those. -Ian Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted May 20, 2002 Share Posted May 20, 2002 Hey i didn't read it that way. When we start calling you Lord Ian then you need to worry I don't think you are going to be able to read much from the plugs in that case, unless you take one out and it absolutely reeks of petrol. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 20, 2002 Author Share Posted May 20, 2002 I'm leaning (ahah) towards the fuel pressure being too low at the moment - it took ages to get going. I'm going to swap back the (known good) j-spec pump, see if that changes anything. -Ian Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted May 21, 2002 Share Posted May 21, 2002 The problem as I understood it was that the car fails to idle and thus cannot be affected by any changes made to the air flow signal (MAP pressure) by the Apexi unit. Fine it needs to be modded in open loop under boost before really hammering it but at idle this is closed loop operation and thus controlled by the O2 sensor output (amongst other things) So if the sensing unit is the O2 sensor and the control unit is the injectors I would hazzard two guesses... 1: (like Paul and others) that it is too rich (I think we agree on that one) due to fuel pump regulator changes/failure maybe. You could argue the injectors are bigger but I know a number of people have done this mod and it does run rich to begin with and then learns to lean things off in time, certainly good enough to go for a gentle spin in the car. 2: The O2 sensor has been damaged from you previous earthing fault causing you drop in fuel consumption (before you changed the injectors) and now due to the bigger injectors is way out and running rich enough to stall the engine. Either way I think the answer is measuring the O2 content. Firstly take the O2 sensor out and clean it in a cup of lemon juice or something to remove any deposits and try again. Then take measurements of the O2 output or as Paul suggests a better wideband AFR (As the O2 sensor will likely just show rich, which is like leaving a door open and placing a sign next to it saying DOOR IS OPEN! Obvious...) You could swap out the O2 sensor with Alex's, if he's willing to try that. Or check the fuel pressure from the FSE. Regards Pete Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 21, 2002 Author Share Posted May 21, 2002 Ah, now, that thing about the o2 sensor being shafted is interesting, as Brian Duff was getting the same poor mileage I am, and he had a knackered o2 sensor. Potentially it got fried during the earthing fault, as it was since then that the car has been running rich! I agree with point 1) - it's not a cutting edge mod, others have done it before me. I'll take the sensor out and clean it (lemon juice? What about cheap vodka?) have you any idea what voltages it should be kicking out? Or should I just get a new one anyway? -Ian Quote Link to comment Share on other sites More sharing options...
Adam W Posted May 21, 2002 Share Posted May 21, 2002 I happened to see in the TRSM for my Mk3 last night that the test for the O2 sensor involves seeing how many times it cycles between 0 and 5 volts at different revs, with the engine warm. I don't know if you can get yours to run for that long though! Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 21, 2002 Author Share Posted May 21, 2002 I called Brian and he said that if the OX1 diagnostic pin reads something below 0.4v, then it's buggered. We are talking 0.01 to 0.1v, sorta thing. Running rich, it should sit at 1.0v! So, that's an easy test... -Ian Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted May 21, 2002 Share Posted May 21, 2002 Yes, during closed loop idling the voltage should hunt between rich and lean. However when cold it'll just stick to RICH all the time as the car warms up, it's a cold start thing. Only when the engine temps increase does closed loop operation begin and the O2 reading hunt up and down about the Stochiometric point of 0.6V. So beware when observing the O2 reading. So it goes.... Cold Start Closed Loop (Hit the accelerator and then) Open Loop (keep accelerator at constant revs) Closed loop after about 1s Use Vodka, you could still drink it afterwards and your taste buds wouldn't know any different. regards Pete Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 21, 2002 Author Share Posted May 21, 2002 Would that explain why, when started for the first time, it lasted a good minute or so before dying? And subsequently, when the engine was juuuust warm enough from running for a minute, it would die within 10 seconds? If I start it and immediately modulate the throttle a bit, it may stay alive as it doesn't go into closed loop? Would that be a valid test? Additional from edit - the ECU defaults to a preset fuelling amount as soon as it's started, which is fine if now somewhat overfuelled. Then it switches to reading off the o2 sensor to attempt closed loop mode once the engine has warmed up a bit (like, after a minute or two). So if the o2 sensor isn't working and indicates a very lean condition, it will richen the mixture up even more than the initial startup level, and thus kill the engine? -Ian Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted May 21, 2002 Share Posted May 21, 2002 So if the o2 sensor isn't working and indicates a very lean condition, it will richen the mixture up even more than the initial startup level, and thus kill the engine? "I love it when a plan comes together" Yes, I think you're on to a possible cause. It certainly cannot harm to clean it or try fitting another (new or 2nd hand) At least eliminate it!!!!!! Pete Quote Link to comment Share on other sites More sharing options...
Nic Posted May 21, 2002 Share Posted May 21, 2002 Where is the O2 sensor located for future reference, anyone have any pics with a big obvious arrow pointing to it? Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted May 21, 2002 Share Posted May 21, 2002 Its the thing mounted into the top of the exhaust manifold, just below the turbos and just before it connects to your downpipe. Visible from the top of the engine looking down (obviously) Pete Quote Link to comment Share on other sites More sharing options...
Nic Posted May 21, 2002 Share Posted May 21, 2002 Thanks Pete, That'll be the sensor I saw at the weekend when I watched my EGT temp gauge being fitted, the sensor for this was fitted along side the O2 sensor. cheers Nic Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 21, 2002 Author Share Posted May 21, 2002 Originally posted by TRL Performance "I love it when a plan comes together" Yes, I think you're on to a possible cause. It certainly cannot harm to clean it or try fitting another (new or 2nd hand) At least eliminate it!!!!!! Pete Righto - I took it out, cleaned it in alchohol, got a lot of particulates out, and refitted it. No improvement. No response to throttle either, apart from dying faster than leaving it. I measured the voltage drop between battery -ve and the diagnostic port terminal OX1 (the oxygen sensor's output). I was lucky if it read 0.02v, mostly it sat at 0.00 to 0.01v So - does that indicate the o2 sensor is buggered? Shall I order a new one tomorrow (+ gasket + studs + nuts)? -Ian Quote Link to comment Share on other sites More sharing options...
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