Frosty Posted May 8, 2015 Share Posted May 8, 2015 I really need help but you all know that anyway. Maybe some chemical assistance is needed. Right to the problem. Picked up a 2001 Nissan Stagea with a dead engine. Scored a good second hand engine and installed it without drama. Did about 500k's and it developed a problem, started as a miss and has slowly got worse. As it stands now it just cuts out about mid throttle, firing every now and again, comes right as soon as you lift the pedal. So far I have discounted by replacement or testing. Sensors where checked and found to be the same, did find a broken injector plug so swaped out the small bit of loom that was damaged. Lift pump, replaced. Direct injection pump, replaced. Plugs, replaced. Coils, replaced. Throttle body, replaced. Injectors, Checked for flow and found to be good. Blanked of the Swirl control valve. Cleaned every conection and earth in the engine bay. Had the inlet off cleaned out checked for leaks and made sure the small inlet butterflys are working. Checked the inlet and vacume lines are leak free. Had it into the Nissan guys to check the error codes, Mass Air Flow sensor and Swirl control valve came up. I've now had two different MAF sensors in it, one second hand and a new one, I have also taken the blanking plate out for the swirl control valve so the CEL is now of but the symptoms are still there. Had the Oxy sensors checked. Variable cam timing, would have come up when error codes where read. Timming chain, again it would have come up as an error. Fuel. ran the tank as low as I dared and filled with 98 octane. Replaced the in tank filter. Bleed the fuel system. Tried manual shifting the gearbox in case it was something to do with the kickdown function. Removed the air filter. Can't be the fuel filter, there isn't one fitted in these, came as news to me but there you go. Had the throtle body of and cleaned the gallerys out. Made sure the Fly By Wire is moving the throtle butterfly all the way. I doubt the ECU is the problem as the engine runs well other than this problem, good responce and normal fuel use. Put the pedal to the floor and left it there to see if it clears, didn't help. To put it mildly I have found this extreamly frustrating I've near put a hammer through the windscreen at times. I've spent dam near as much as I payed for the car and replacement engine together for no gain not to mention about 200 hours of my life I will never get back. Any one have an idea of what to look at next, or should I just bung a block of wood under the pedal? Quote Link to comment Share on other sites More sharing options...
Beaver Posted May 8, 2015 Share Posted May 8, 2015 tried another ecu? Quote Link to comment Share on other sites More sharing options...
AllTorque Posted May 8, 2015 Share Posted May 8, 2015 Accelerator pedal sensor?? 1 Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 8, 2015 Author Share Posted May 8, 2015 If I could find one I would but as of this moment I can't. I did ask if it was possable for the ECU to be causing it when I got it's brain sucked for errors, they said it was unlikely and I tend to agree with them. The ECU in the M35 is not knowen to give problems, nearly always cam chains and MAF sensors, both removed from the list of possable problems. Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 8, 2015 Author Share Posted May 8, 2015 Pedal sensor, possible, wonder if the Skyline/Maxima ones work? Quote Link to comment Share on other sites More sharing options...
JBlades Posted May 8, 2015 Share Posted May 8, 2015 Pcv valve? Unsure if these have them, but recently had that issue on my pulsar, Pcv valve was blocked causing hot air to go back upto the afm, making it run like a sack of hammers. Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 8, 2015 Author Share Posted May 8, 2015 PCV valve is one of the first things I blocked of when I started just forgot to put it on the list, did the main breather line as well just in case the engine was running positive air preasure in the crank case. The VQ25 uses a MAF (Mass Air Flow) they work in a whole diferent way than an Air Flowmeter. Work on air density the same as barometric pressure for the weather, I think the flow sensor is optical there's an air temp sensor in the unit to. clever little buggers. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted May 8, 2015 Share Posted May 8, 2015 I haven't read this but.. I had one of these cars (250rs) and lost a ton of money on it when the can chain stretched and the actuators went poo. That engine is the worst of the worst for reliable motoring past 100,000km. An absolute dog. You'd be better off with something rotary powered as at least their cam chains are CHEAP to replace. I ended up selling our one for a huge loss (is yours blue on 18" Stagea autech wheels and from hamilton?) But if I had more time I may have considered an RB (or similar)swap. They are a beautiful looking car and nice to drive...... Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 8, 2015 Author Share Posted May 8, 2015 flyingbrick. Someone had to say it. Had a good chuckle with the Rotary Cam Chain, thanks man I needed a good laugh. My one came from Rotovegas and is stock very boring. The cam chains are a pain but they have CAS sensors (cam not crank) on them and no reported problems from the ECU. They are set up to bring the CEL on if they are beyond tolerance. Maybe a 20B+T might be the answer. HHHMMMMMMMMMMMMMMMMMMMMM NO NO NO. Or A LS1 crate engine folowed by more no's Got this thing so I wouldn't want to fuck with it just drive it. 3.8 Holden might work though as a last resort. 1 Quote Link to comment Share on other sites More sharing options...
AllTorque Posted May 8, 2015 Share Posted May 8, 2015 It's probably worth double checking all the earth cables as well. Make sure the all have a nice clean contact point and the bolts are tight. Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted May 8, 2015 Share Posted May 8, 2015 fuel pump? just throwing that out there. nissans don't have the most realiable ones but would assume that would be ruled out by now Quote Link to comment Share on other sites More sharing options...
Burntrubber Posted May 15, 2015 Share Posted May 15, 2015 I'd say say fuel issue my wrx did it years ago would start idle fine drive ok at low throttle no boost as as soon as i gave it a little more it would fall flat and come back to life as soon as I lifted off. I only drove it like that once started on my way to work so I just got a tow truck to work where I figured out the pump was on the fritz. Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted May 15, 2015 Share Posted May 15, 2015 Actually along same lines make sure tank breather is fine other wise fuel has to work against the vacuum of the tank draining. Sounds weird. But I had this on my carry van after fitting alot of wasted new parts at it. Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted May 15, 2015 Share Posted May 15, 2015 Ie try driving with fuel cap off or loose Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 15, 2015 Author Share Posted May 15, 2015 Seedy Al you may have something there, will try it tomorrow. A comment / report on replys and progress and thanks to all. Yeah I agree, fuel system is where the symptoms would lead me as well. One real big issue though is it has nothing to do with the pumps. The lift pump has been swaped out with a known good one and the mechanical Direct Injection pump has also been replaced, again with a known good one. ECU error code would indercate a MAF (AFM) problem, I have had three diferent ones in the car and the last two where brand new. So we have a fuel problem via the symptoms and a AFM problem according to the error codes and the normal ways of fixing them have been explored. So we end up with an exotic fault that conventional repairs have not fixed. I've considered a Knock sensor issue but doubt it could adjust fuel and spark far enough to cut power all together. Another thought is a broken or damaged wire between the AFM and ECU but my multimeter says no, a visual exam also confirms this. Blocked cats was another thought but the fault would change with exhaust temp and it's always the same fault, nothing I have tried has made the slightest differance except unplugging the AFM which makes the problem even worse. About the only thing left is the ECU but I have no real experiance with this style of engine management. These Direct Injection Lean Burn systems are new to me. One thing I do know is if there's anything major wrong fuel economy turns to shit and that's not the case. I've just done 500km's for $80 of 98 octane which works out to 14km's/lt I would say at very low throttle but the car would still cruise at 120 and I did for bits of the trip. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted May 15, 2015 Share Posted May 15, 2015 Put the car in a shed with a heater and dehumidifier. Ours also started playing up after going through a puddle caused wiring issues. Quote Link to comment Share on other sites More sharing options...
bigfoot Posted May 15, 2015 Share Posted May 15, 2015 timing chain. Workmate had a QG18 with similar symptoms,guy he sold it to changed the chain and it ran sweet. This was after we replaced every sensor on the engine 1 Quote Link to comment Share on other sites More sharing options...
AllTorque Posted May 15, 2015 Share Posted May 15, 2015 Check the egr valve isn't too dirty. If it doesn't close properly you can have fuel mixture problems. Did you check the accelerator pedal sensor yet? Quote Link to comment Share on other sites More sharing options...
japawagons Posted May 15, 2015 Share Posted May 15, 2015 I'd you disconnect the battery and then reconnect it. Do the symptoms change or improve and then get gradually worse? You need wideband and scan tool for live data. To check ecu decisions, and to check the engine is actually lean. Taking stabs in the dark is a waste of time. If it is logging fault codes you need to rectify the cause of these codes before you can move on even if they are not the cause of the running issue. Quote Link to comment Share on other sites More sharing options...
japawagons Posted May 15, 2015 Share Posted May 15, 2015 Sorry to double post. You've just got me thinking and I love this kinda problem, just ask Yowzer, these issues are what I spend my work days fixing. Where are you in the NZ? Have you checked the ignition system? Is it a constant fault from cold start up to running temp? Your description of the MAF sensor is confusing as its quite incorrect. So its a MAF sensor, the are a combined air temp and air flow meter in a housing. They do not work on air pressure, they measure the volume of air moving and then its temp to calculate density. MAP (Manifold Absolute Pressure) sensors measure air pressure, these are a very different sensor. And MAFs are most definitely not optical. All vehicles have fuel filters, there seems to be a new myth about modern vehicles not having them. It will be in tank as part of the lift pump assembly. Being direct injection there should be a fuel pressure sensor on the rail or post high pressure pump. The live data for this needs to be checked. Coolant temp vs air temp (live data) should be compared when dead cold. Should be identical in a perfect world. Within a few degrees in reality. If it was me I'd have a wideband on it and a scope on the ignition coils. This will check the mixture and spark condition. Key is to identify the fault not the symptom as in lean / rich, poor spark, mechanical fault, rather than trying to feel out the symptom of a "miss". Hope this makes any sense / helps. 1 Quote Link to comment Share on other sites More sharing options...
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