What's wrong with idle now then? O2 sensors shouldn't need any running in.
Is it idling OK now? Closed loop at idle on bank2?
Probably more than just coincidence that the bad starting and poor idling started just after you'd changed lambda probes and I've seen same/similar happen before. When I've seen it happen a few possible explanations have occurred to me. One theory goes that behind the scenes there are two types of open loop mode which I'll call OL1 and OL2. OL1 uses only the ECU base map no fuel trim adjustments applied at all (but still adds cold start enrichment and high load enrichment), OL2 works the same as OL1 but also applies the long term fuel trim. In a no fault situation OL2 is used and gives best results (drive-ability and emissions) - the fuel trims have been learned to provide correct mixture when the engine was warm and in theory when emissions equipment was working properly, the lambda's don't work properly until they're warm enough and are also incapable of measuring the rich mixture necessary during early stages of engine warm up... But still if we want to run as close to correct mixture as possible we should apply the long term fuel trim, or if we want to run a 10% rich mixture we should apply the long term trim + 10%. Or put in another way, if the engine has been running correct mixture which happens to be when LTFT is at +10% and then we cut the wires to a lambda probe while the engine was running we'd expect mixture to remain correct if LTFT remained at +10% or to run lean if the ECU suddenly stopped applying fuel trims because it had detected the fault. Just before you swapped the lambda probes the ECU might have been running in OL1 mode because it had detected a problem with important emissions equipment (e.g. lambda heater circuit) and OL1 mode could give decent results, but before switching to OL1 mode when probes first went bad fuel trims could have been learned incorrectly. By fitting the new probes the ECU sees the heater circuit fault has gone away and switches back to closed loop mode but applying the incorrect fuel trims. There may be an element of when the ECU has first switched back to closed loop mode after running OL1 the long term trim that applies to idle is re-based to be same as an off-idle fuel trim. Off idle fuelling/trims are less fussy than idle fuelling/trims, the volumes being measured (air) and metered (fuel) are far greater and easier to measure/meter within a percentage tolerance range, also the volume of exhaust gas flowing past the lambda sensor is greater so the lambda voltage more quickly responds to exhaust oxygen content (mixture) which is the main reason ECUs respond to lambda quicker with increasing engine load (faster lambda voltage flick). Open Loop and Open Loop (Fault) may correspond with OL1 and OL2 but not necessarily in that order and not under all conditions.
As an aside, not helpful to you because you don't have LPG... My last post I described a way I've got around the running OK closed loop off idle but running poor open loop fault mode at idle problem. Another method I've used is to adjust LPG calibration to make mixture OK for idle on LPG and gradually steered LPG calibration to bring fuel trims back to a range where mixture is also OK for petrol. The idea in both methods is to keep the engine running closed loop with correct mixture instead of reverting to open loop fault mode (which can happen if fuel trims min/max out for long enough) for long enough that fuel trims are steered, don't let lambda voltage hang high or low for long enough to cause the ECU to interpret this as a fault and become latched in fault mode with poor running.
I've seen similar problems with them but it's been a while. I don't have a Nano.
If it idles in closed loop mode with correct mixture (flicking lambda voltage) but idle is slow it points to IACV or TPS,
if it runs in closed loop mode with correct mixture off idle but reverts to open loop (and probably poor mixture) at idle I've found it can help to run the engine at fast enough idle to keep in closed loop mode, gradually reducing idle speed using the throttle as closed loop mode becomes active at lower rpm. And dare I say it, disconnecting the battery before all this seemed to help.
Seen missing Orings on MAFs on a lot of them that run fine so doubt that would be the problem.
Odd restart.... Is that randomly or cold engine versus warm engine?
If you do I'll be tempted to buy a P38 and join you :-)
Already lots of intelligence from Gilbert... most of the time lol.
Just P38's? A local guy (used to run a car paint shop) collects old military vehicles, tanks etc, probably has something that looks like a half track but would guess they're not allowed. In fact, would they be OK about a convoy going anyway?
If we were jealous before we're going to be even more jealous now!
Not sure if my ww2 reference in 'history suggests' went unnoticed lol.
I'd love that kind of road trip too, quite an adventure but also reads like it takes a bit of military style planning.
History suggests taking the most direct route to Moscow is probably the best bet for Western visitors but fuel is more readily available in the South?
There isn't a pre-defined relationship between voltage and trim... You've seen yourself that voltage can fluctuate the same on both banks while trims are different. It's unlikely one of the new lambda probes is at fault or one less compatible than the other if they're both the same spec.
The engine has a trim for each bank specifically to allow a different trim on each bank, there would be little point in having a different trim for each bank if trims were supposed to be exactly the same. That said, we usually expect trims to be similar - Trims are there to compensate for tolerances in sensor readings and mechanical aspects such as fuel pressure, injector flow rates, valve train (effecting airflow), even to compensate for the ECU's fuelling map not being quite correct. Some tolerances change over time as mechanical components and sensors age/wear. If everything was made to an exacting standard and remained the same as it ages trims wouldn't be necessary. We expect trims to be similar because tolerances such as fuel pressure and MAF readings will equally effect both banks of cylinders, wear on valve gear should be about equal, good injectors should flow almost equally. A small difference in trims isn't unusual, a large difference in trims could point to something being different between banks, since bank lambda readings are the average of the 4 cylinders on the bank something effecting just one cylinder can cause a bank trim difference - a leaky petrol injector on one cylinder might cause it's bank readings to have more negative fuel trim (rich), worn valve gear might cause a cylinder to pump less air resulting in the same more negative fuel trim (rich), a vacuum leak on one side of the engine might cause positive fuel trim on that side (lean).
The expected / normal fuel trim isn't necessarily zero, an ECU's base map (with zero trims) may intentionally be set to provide slightly lean or rich mixture before fuel trims are learned (even if the engine, sensors and fuel system components are all exactly in the middle of tolerances, bang on spec) but the ECU is always expected to provide correct mixture when fuel trims have been learned.
Before changing the exhaust it would start OK from cold but had problems restarting when warm... Now we're talking about trims and poor idle but no mention of if it starts ok when warm now. Anything else to note after changing the exhaust/sensors? If the engine seems good and drives/idles well enough, if trims aren't miles apart I would drive it for a while and see if the idle improves / trims come more in line / restarting when warm is any different.
I wouldn't dare put equivalent of 4 years full time work into it even if I kept it in a bank vault unless I could sell it for equivalent of 5 years wages and live out of bins for 4 years! So if I was into RC stuff (and I am interested, used to go and watch them at Pontefract race course) looks like I'd have to go the electric motor route too.. maybe add a speaker to make it sound like a V12 lol. Forgotten you're into RC stuff, maybe come and watch yours one day?
Not to belittle RC stuff but incidentally my son has been taking flying lessons near York on Saturdays over the last couple of months and has been at the stage for a while now where they sometimes let him go up by himself. When he's well enough qualified we intend on hiring a plane and flying to maybe Newquay airport, I expect it will seem a bit weird trusting son I taught to drive a car fly the thing and not know if he's doing right or wrong. Regards the original topic I know they wouldn't let me convert a plane to LPG but they have no electric planes either, even if we're all forced into electric cars and have heat pumps instead of boilers the country will still hardly be carbon neutral.
Morat wrote:
Brushless motors and Li-Po batteries have revolutionised RC stuff. There are some seriously impressive models out there running on LiPo and they're much more reliable than the old "gassers".
Not knocking them, but a model say spitfire powered by a model V12 engine would be more impressive than a model spitfire powered by an electric motor?
Help the missus to get the housework done quickly with the improved vacuum cleaner for her birthday then cut back those overgrown trees in the garden enter link description here. Might even help in the garden ;-)
I miss marvelling at my nice grey exhaust after a 3 hour 120mph blast to Cornwall, especially after replacing valve stem seals and setting the carb and ignition timing up nicely lol. No more grey exhausts or maintaining 120mph for long :-(
I see it as Richard said with the clarification by Miles. But did anyone suggest going back to leaded fuel would be a good idea? Edit - I wouldn't agree with that.
Prompted me to check out Dyson batteries, V7 has a 21.6V 2 amp hour battery so 43.2 Watt hour, same battery could power a 1kw old Hoover motor for 2mins40seconds. If the Dyson runs for 30 mins between charges it must only have an 80 Watt motor - no wonder they don't work as well as a corded vac! Motors have been fairly efficient for a long time so not much room for improvement... Digital motor, is that a normal motor but fed with PWM power to maintain same rpm under load? Now Shark vacs are advertising that their new models feature hair removal grooves to prevent the scrubber bit getting clogged up and maintain cleaning ability (cos we don't like hairy scrubbers lol)... so not because hair on the scrubber bit stalls the motor and prevents it working at all then? Should invent a small petrol engine'd vac, would only need a petrol tank of a few millilitres to have the same power and running time as the Dyson and I could clean up emissions by converting to run on a lighter refill canister ;-) We have a Shark, it's shit, but I think if I were to buy a V6 or V8 vacuum I would be even more disappointed!
Morat wrote:
Sounds like those vintage looking French vans with corrugated sides that get converted into Coffee stands or Pannini Wagons. The ones I see at shows arrive and leave on a trailer anyway!
That kind of thing but they were intended to get used and I did see one delivering locally that the firm had built before I started there. Staff comprised the business owner who hardly ever got hands on, me and an old bloke who was good but took an age to do anything, I was old bloke's apprentice. Could have been an interesting job but was boring (slow pace) and never going to last, can't have been profitable for the owner.
davew wrote:
Thanks for your detailed explanation about converting Black Cabs Lgpc: Overall then (longer-term) it may well be better for owners to take that paultry £10K grant towards buying an 'Alternative Fuel' vehicle after all (?)
Would have to be more specific about 'alternative fuel vehicle' because that covers all of LPG, electric and hybrid vehicles. Assuming you mean a new electric only vehicle the taxi driver also has to weigh up how lack of range and charging time might cause downtime that could lose earnings... Downtime just driving around London but if he picks up a punter who wants to be taken to Oxford etc he may not be able to take the job. I dunno if black cab drivers often get asked to go that far!
It should really cost much less than £10k to swap the engine in a black cab and convert it to LPG.. But because of red tape and ill advice they're fitting an expensive new design petrol engine that will probably kick out similar (perhaps worse) emissions running on LPG than an older design petrol engine running on LPG. I've got mates who would happily buy a 2L Ecotec from a scrapyard and fit it in a black cab for maybe £1000, they'd probably do the first one for the fun of it (but would probably rather stick a V8 in lol). That done convert it to LPG. Would never happen due to red tape etc even though in reality this would be the best way to minimise emissions.
Expanding on the above point - The whole point is of course about emissions, granted local air quality (particulates etc) specifically in this case but also they want to lower general CO2 output. So could beg the question why fit a brand new engine when they could just have sourced second hand engines and rebuilt them, fitted them in cabs and converted to LPG.
For a short time many years ago I worked for a small firm producing custom vehicles, the type of very old fashioned looking vehicle that special herbal tea or small breweries buy to use as delivery vehicles, all custom built just about from the ground up. We even had to design and manually build one-off exhausts and pedal boxes for each vehicle, no 2 vehicles really the same. But we fitted a brand new expensive diesel engine in every one, the engine quite a high fraction of the overall cost of the car. The cars didn't do much mileage - I suggested we might offer to fit older scrapyard bought engines in the new cars for customers who wanted the special car but weren't fussed about them having a new engine if they could save £thousands, could have offered rebuilt old engines... the boss thought it a crazy idea.
Maybe Morat has 'the knowledge' and doesn't need a satnav ;-)
davew wrote:
Ok, so a question aimed (mainly) at Lpgc:
As you will know via LPG conversions London Black Cabs can have their 'lives' extended from the 12 years being proposed back to 15....
Q: Is it worth it ?https://www.london.gov.uk/press-releases/mayoral/24m-funding-boost-for-black-cabs
Black cabs are diesel so need to have the engine changed before LPG conversion.
I was approached about this some time ago by a firm who are involved with the engine swaps but iirc the engine they were fitting was direct injection (I forget which engine) so isn't ideal for LPG conversion. Parts are available to convert the engine in question using port injection LPG equipment but the best way to convert a DI engine is a different type of LPG system that squirts LPG in via petrol DI injectors - Prins Liquimax or similar. I really don't like converting DI engines using port injection LPG equipment... I like to get LPG systems running spot on and it isn't really possible when fitting port injection to a DI engine, it's always a bit of a fudge, and besides, a DI engine running a port LPG system will always use a bit of petrol and the authorities may take exception to that.
The choice of engine (it being DI) could have been due to lack of decent research by the engine fitter, could have been due to there being a minority of engines (Euro6 compliant or whatever) that would fit in a black cab, or could have been because they had first seeked the advice of a Prins or similar dealer who advised the engine because it is DI to prevent the majority of installers from being able to be involved in converting the cabs! I'm a bit far from London and the profit margin on each cab wouldn't be great, worth it if I wanted to keep a big shop busy but I'm a one man band and there'd be a problem training people up if I decided to expand to cover such a contract.
Instead of London I've made a few attempts at making inroads into converting Leeds taxis (not black cabs) but it's proving difficult to get a response. My daughter is married to the son of a guy who used to be traffic/road planner for Leeds now retired (yes I know Leeds road planning is shit lol), I don't know the guy really, met him once at the wedding but may see if he can put me in touch with an organ grinder at Leeds council. Another obstacle is that councils tend to expect red tape / regulation, UKLPG play on this so councils are likely to want installers converting cabs to be UKLPG members... But I've been outspoken against UKLPG.
I'm getting a lot of enquiries from Leeds taxi drivers as it is but they want a system fitting for £800 etc... Was also approached by a firm that supplies taxis, they asked me to quote for converting 30 cars, the contract went to the lowest bidder which I knew definitely wasn't going to be me. Iirc the 30 cars were DI anyway and the installers would be fitting port injection systems on them (probably Stag)... Those 30 cars will get the lower price for entering Leeds but they will have all sorts of problems running on LPG and I expect to eventually put a lot of them right.
StrangeRover wrote:
What about HGV's etc that Have to use Diesel, don't see there being an EV HGV in 10 years, unless some genius lives among us!!
I say start producing Rolls Royce Merlin engines again, stick them in HGV's instead of the diesel engine, convert them to LPG lol. In the meantime a couple of 500cube big block V8's in a truck would work OK. Converted another 500cube 8.1L 'Workhorse' (Chevvy) V8 in an RV last week, was collected by it's owner yesterday, have converted a few other similar and V10 RVs for the same bloke in the past, bloke is retired but keeps busy doing RV's up.
That doesn't add up to me Gordon. Trump may not care about the environment and doesn't seem concerned whether people take up green stuff like electric cars, doubt he'd want people/US to get into debt over it. Johnson reckons to care about the environment but again doubt he'd want people/UK to get into debt over it. Where do pound signs come into it or just VAT on sales of new cars etc followed by what? Right wingers generally see debt and high taxes as a bad thing more than the left do? Corbyn is more far left wing than far right, he's the fella who's said he wants the UK to be carbon neutral by 2030, I'd bet he's not as concerned about debt private/country as the others mentioned.
On Glasgow being the first to go carbon neutral - If I wasn't allowed to drive my ice car past it and I was visiting Scotland I'd simply avoid the area and route via e.g. Edingburgh A1 M90, as would most people with ice cars, even some logistics companies would avoid it, probably not so good for the local economy. The same might upscale to involve the whole UK if the UK is first to go carbon neutral.
But presumably you would agree with Clarkson if he said ice cars shouldn't be banned from the UK in 10 years Dave, after all you run a big engine'd one yourself at the moment lol. No need to be concerned about powerplants dying in 10 years if they're going to be banned in 10 years.
Jeremy Clarkson gave Greta a bollocking in his newspaper feature the other day saying she's young / idealistic / doesn't see the big picture / pointed out a few ironies lol.
Imagine in a couple of years receiving a letter from DVSA explaining that in 12 months time it will be illegal to use your P38, your options are to scrap it or SORN it indefinitely to become a museum piece which you won't be able to buy fuel for in future even if you decided to flout the law. Then you choose either not to run a car or to buy/lease an electric one which has crap range and takes an age to charge on a typical charger. China starts to produce most of the electric cars we buy regardless of where tech was invented, they just copy tech and sell it back to us while China continues to run ice cars and power stations. Net result of a negligible reduction in global emissions, negligible improvement in local air quality (compared to running petrol / LPG cars... diesels were always a bad idea) but a hard knock to way of life.
Should we lead by example and suffer knock to way of life earlier than other countries whilst (as a small country and a relatively clean emissions one at that) having minimum effect on global emissions and climate change because other countries aren't following the example?
Ability to run cars on hydrogen, production of hydrogen, production and recycling of Li batteries are covered above so I won't go over that much again. Yes we can convert ice cars to run on hydrogen using some of the same components we use for LPG conversion but with a different tank, fuel lines and pressure reducer. Tanks and other components can be difficult to design for hydrogen, apparently it degrades metal. Engines running on hydrogen make about only half as much power as on petrol or LPG so you might need V8 power even in a little car but more likely you'd get a 3 cyl turbo or a fuel cell.
EV's (battery) and perhaps even hydrogen - Your emissions now comprise nuclear waste and what comes out of the smoke stacks. Battery worse than face value due to energy that goes into mining lithium and recycling.
I doubt many believe it possible in 11 years... but if they try to pull it off it will have an effect on us while they're trying.