Enrichment in acceleration works in different ways depending on age of ECU.
It makes sense to explain how the newer ECUs work first, then it's easier to see why the enrichment in acceleration facility is there at all and why it is more important on older ECUs... Most of you will have the older type ECUs.
On newer ECU's the slider doesn't allow for enrichment at all, full right on the slider gives just the mixture that the map/pressure compensation/temp compensation provides, left of full right leans the mixture during acceleration. On the newer ECUs the only real correct position is full right, anything left of full right points to calibration/setup issues. That's because the newer systems are truly sequential - they take Pinj readings from every petrol injector and (supposedly) each cylinder's gas injector pulse length (Gnj) is calculated individually based on each individual cylinder Pinj's, furthermore the gas pulse should start at almost the same moment that the petrol injector pulse starts (where almost means at the same time or within about 2ms based on other settings such as 'extra injection filtering' where extra injector filtering in theory allows very short Pinj's to be ignored altogether).
The older type AEB based ECU's are not really truly sequential, they take the Pinj reading only from the front cylinder on each bank (blue wires), then each cylinder on the same bank gets the same Ginj as the front cylinder Ginj. Now suppose that between the front cylinder injection pulse and another cylinder's injection pulse on the same bank the driver stamps his foot down... At high rpm the manifold pressure won't have time to increase much before the other cylinders on the same bank inject fuel, at low rpm the manifold pressure will have more time to increase between injection pulses on that bank.. In cases of both high rpm and low rpm the mixture for the rear 3 cylinders (particularly the last cylinder in the firing order) will be leaner than the front cylinder mixture because it didn't read the rear 3 petrol injectors pulse times it just assumed they would be the same as the front cylinder's pulse time. To address this the system has the enrichment in acceleration slider.. The default setting of the slider (usually somewhere near the middle) gives a bit of enrichment to the rear 3 cylinders when the ECU notices manifold pressure and/or Pinj on the front cylinder rising quickly... The enrichment is a fudge, but no more of a fudge than the acceleration enrichment that a petrol ECU provides. Since the newer type ECUs read individual petrol injector pulses to calculate individual gas injector pulses the newer ECUs don't need to add in the fudge themselves because they are reading Pinjs that have already had any necessary acceleration enrichment fudge added by the petrol ECU.
The gas ECU applying an acceleration fudge (instead of the petrol ECU's fudge) isn't really a drawback. The only real drawback of the old type ECU over the new type is that it doesn't necessarily pulse gas injectors at the same time as petrol injectors are pulsed - the new type uses start of petrol injector pulse as trigger for start of gas injector pulse whereas new old type does this for the front cylinder but then spaces the rear 3 cylinder gas injector pulses according to only rpm. Not a problem on older engines but can be a problem on newer engines with features such as VVT/Atkinson cycle.
The acceleration slider won't make any difference to mixture with your foot in a constant position on the throttle, even if you're holding foot flat out, because with constant throttle manifold pressure and Pinj's stay about the same. The slider is used on older ECUs to dial out drive-ability problems when you're changing throttle position (hesitation from lean running with too lean mixture / misfires from too rich), can even be used to compensate a bit for long pipe lengths (needs to be richer during acceleration so more gas reaches the cylinder's intake port in time to make mixture correct with rising manifold pressure). Usually set while the engine is idling then stamping on the throttle (idle to flat out /idle to near flat out / idle to partial throttle) looking for crisp throttle response, and adjusted again while driving.
If you want to change top end mixture while throttle is held constant,you use the other mapping tools (map itself etc). Going too rich on LPG will result in less power than a stoch mixture on LPG because the greater amount of gas displaces what could otherwise be airflow into the engine (hence negatively effecting volumetric efficiency) to a greater extent that going too rich on petrol... You still want a rich mixture at high loads but not always as rich as would make more power on petrol. If you have a 0-1v lambda probe, where on petrol max power might arrive at richer than the narrow band lambda is capable of reading, on LPG max power might arrive at as low as 0,7v but we might still go a bit richer than 0.7v to protect the valves. Set the map first, then adjust the acceleration slider.
Wouldn't bother with a rolling road, they never give same under bonnet temps as driving on a real road. Under bonnet temps effect the LPG vapour temp (and reducer temp) readings which effect the mixture. If you've been sat idling in an LPG car for a while and under bonnet temps get high, if you suddenly set off and boot it the vapour temp reading will for a while be high, causing the mixture to be richer than it will be after a while of driving on the road when vapour temp readings have settled down to normal. Greater volume / faster throughput of gas through the reducer mean that gas temp readings fall when booting it but there is lag between booting it and the temp sensor reflecting the correct temp of gas reaching the injectors - If you have hot under bonnet temps to start with and then set off booting it for a while the mix will start rich and get leaner until temp correction has fully caught up, should be setting mixture when compensation has at least nearly caught up. A rolling road won't keep the rad/engine as cool as real road speeds, AEB systems also compensate mixture for reducer temp. Seat of the pants while reading trims/mixture is probably better than a rolling road.
Forgot to mention..
Got back from holiday in Malta the other day. 'Miss European' contenders were staying at the same hotel as us. several from each country. We saw them mostly on an evening all dolled up and posing for country group shots and single shots outside the front door. All week my girlfriend was suggesting we relax around the pool rather than go sightseeing but the one day I agreed to sit beside the pool she suggested we go out and do something else. When we got back that evening we'd missed all the poolside bikini shots...
gordonjcp wrote:
Billy Connolly used to go climbing with my dad, who taught him how to play a bunch of folk songs on the guitar in the Clachaig in Glencoe ;-)
Whisky 'on the rocks'? ;-)
There is a successful musician who regularly contributes on this forum but it's up to him if he wants to ID himself. Dare say he's been in Abbey Road studio considering the type of music he's into.
Had another guy here with a P38 the other week who''s a bodybuilder and part time actor, currently features in a TV ad, will be in next season's Game Of Thrones and has been in a TV series but I forget which ones he said lol.
My dad was a club turn for 40 years and a theatrical agent later on. In his late teens or early 20s he was lead guitarist in a semi famous band called Tony Sheridan and the Sundowners. When I was a kid Billiy Connoly, Tony Christie, Marty Caine and no doubt some others I've forgotten about visited, Billy Connoly wasn't as famous back then but the others were. Dad used to book Tony Christie and Gary Barlow into clubs, Gary Barlow once slept in my dad's uncle's Hymer Mobil motorhome in the yard where I now convert vehicles to LPG. I recently converted a Nissan Elgrand to LPG for a guy from the South East who was once a roady for Tony Christie - small world.
My grandad played darts with President Rosevelt and Churchill onboard HMS Price Of Wales.
Met loads of famous people when I was DJing but I'm not very good at recognising famous people. Once I was DJing at some type of bash for Channel4 in Liverpool Town Hall and tried to cop off with a bird I didn't recognise as Sonia the 90s singer... turned out she just wanted me to play some of her records lol.
My Scouser mate's dad used to work the clubs like my dad, so when they were working in each other's areas they used to stay at each others houses (same crack as Billy Connolly stopping here). My mate now sells motorhomes, his sister runs another firm hiring out big motorhomes to famous people to stay in when they're touring. Some of those people have squeaky clean images but he reckons it takes ages to get rid of the smell of weed when some of those people have stayed in them.
My daughter is a scout leader and has met Bear Gryls loads of times, I think she mentioned he turned up once 'in a rangerover' but I dunno if it actually was a rangerover and even if it was dunno if it'd be a P38.
Didn't Nigel Mansel used to own a P38 and rolled it on a motorway?
White paint - Tipex might as well shift from stationery suppliers to car parts stockists, I always keep some around lol.
I didn't realise it was a common problem.. doesn't say much for the specialist who called me in lol.
Maybe a bit off topic - I was once called out to a Rangerover specialist who had an LPG converted P38 that wouldn't run on petrol but would run on gas. Problem was the petrol pump wasn't running but the petrol pump was good and the pump relay was good. I found the problem to be that the petrol ECU wasn't sending power (or earth - I seem to remember the petrol ECU supplies the earth, constant live) to the petrol pump relay. Fixed it by running a fused line from petrol injector positive to the petrol pump relay and an earth to the relay, the alternative might have been to fit a different petrol ECU.
Off subject story - Years ago me and my dad drove a lot of miles to collect a Jeep I'd bought on Ebay. When we got there the owner said 'Sorry but you've had a wasted journey, it won't run now'. Seems he must have been offered a higher price because I quickly found he'd removed the petrol pump relay and on swapping another relay into the pump position it fired straight up, the guy had to sell it to us, told him what we thought of him and we came away with the Jeep.
Email of my oily bits sent Gordon, sorry for the delay, busy busy...
Edit - But you know what... I may have overlooked the fact my results at the top of the list are stickies!
P.s. I'm not in the habit of sending pics of my oily bits and the only pics of others oily bits I'd appreciate in return will be from ladies lol.
I'll try another browser. Currently using Chrome in W10.
Title says it all...
It seems to work that way in opening time but not in oily bits or electrikery.
What would happen if he presented the car for the France/Portugal/Spain equivalent of the MOT with LPG parts fitted but disabled by pulling the fuse, perhaps removing the LPG tank?
Or, not too difficult to remove a reducer (and connect coolant pipes together), remove injectors (and plug pipes), remove the LPG ECU (and reconnect petrol injector wiring using a couple of plugs that just join striped wire to none striped).
Just looking for a get-around for Super4.
Not been on this forum for a few days, had a quick scan through posts since my last visit to catch up a bit.
Pleased to read the idle speed has been cured by elongating the holes as per Gilbert's advice. Not sure if I read there's still a very slight issue with ability to hold rpm at 1000 on the throttle, something to do with transition between off-throttle idle and coming on the throttle? If that's the case, couldn't the TPS be moved in slight steps from current position in elongated holes back toward standard position, small enough steps to allow the adaption to do it's thing? I'm not saying this to point fingers at the elongation method which was obviously a very good call by Gilbert, asking out of interest.
Will take your word on that mate, if I'd read the same posted on some other forum by someone else I might have queried whether the IAV was used as a progression jet.
Still, if the throttle does completely close maybe a cold start could prompt re-learning? Curious about what you said regards the learning only (or much more quickly) applying both ways at the closed position, not both ways for open positions. I've seen them with long standing unrelated issues that have seemed to have caused the IAV to learn to be more open (to achieve high enough rpm in the light of other problems) which have then caused higher than normal idle when the underlying problem was sorted, but I've never had a problem with them re-adapting to bring rpm back to normal idle speed.
Curious then, does disconnecting the battery on Gems reset some adaptive values?
IAV adaptives are reset when the battery is disconnected from a Jeep (yes I know not a P38)... After having the battery disconnected they will immediately stall when restarted unless the throttle is held open a bit, easy to learn the knack of preventing a stall by feathering the throttle until adaptive is relearned though. Trick is to keep the engine running at just under normal idle speed using the throttle and back off on the throttle very slightly every time idle speed climbs a bit until eventually it idles at normal speed without having to touch the throttle.
Seems to be having a lot of problems finding someone who can reset adaptives but does he really need to do that? Well before going to the lengths Super4 has been through trying to find someone to reset adaptives I'd have tried the feathering the throttle method from a cold engine start, which is when the ECU holds rpm at higher than usual rpm before settling down to normal rpm and therefore when we might expect most of the learning to take place.
Hot weather out there so engine won't see 'cold cold', will only see 'warm cold', if no luck during the day I'd try again at night or early morning when the engine is cooler or fool the engine temp sensor into thinking it's cooler.
Never had to hard reset engine adaptive values on any vehicle using specialist equipment, fixed hundreds of P38 engine management issues of all types but never touched a Nanocom, sceptical about it being necessary in this case. Aren't gearbox shift issues associated with duff TPS readings at least on one of Bosch or Gems?
Slightly off subject, I've made TPS's for carb'd vehicles I've owned (to connect the TPS wire on AEB175 systems to, also fitted a lambda in the exhaust). Short bit of rubber gas hose acting as a CV joint between the throttle shaft and potentiometer helps prevent the pot suffering side loads which might otherwise cause premature failure, can get the voltage curve to do whatever you like by playing with different value resistors between earth and the pot / live and the pot / between live and pot output. Bit of faffing but only pennies to make. A normal TPS rotates 90 degrees and output varies between 0 and 5v, if you choose a pot that'll turn about 220 degrees and stick 12v at it the voltage curve will be very similar from the outset.
I wasn't overjoyed with 'Dad my Mondeo stopped working on petrol but will run on LPG except my LPG tank is empty, I know you'e extremely busy but can you bring that full LPG tank from the yard and plumb it to my car so I can get moving again, I'm only 50 miles away' but I couldn't say no.. Cumon Gilbert only a 2000 mile round trip lol ;-)
I've had a scan through posts on recent pages, not sure if the following points could still be a factor or have already been ruled out:
Old TPS wasn't at the end of it's travel with closed throttle, new TPS was (at first) at the end of it's travel. Could the new TPS have been physically holding the throttle open a bit, accounting for the fast idle? Could adjusting TPS to prevent that still have made the TPS show less than typical (and prior) 0.7v in the idle position, giving unsmooth transition between idle and off idle? Or moving the TPS still a bit more cause higher than 0.7v at idle, still causing unsmooth transition but now also causing stalling on return to idle because the Ecu doesn't see the throttle as being closed?
Would've thought that if TPS was set so that with closed throttle voltage was close to 0.7, drive-ability wouldn't be too bad to start with and transition would only improve?
Having said that, one P38 conversion I did sticks in mind. The guy had received his bosses P38 instead of his annual work bonus and made much fuss about 'will the engine still idle nicely on LPG because I've heard this can be a problem'. Come the day he was dropping his P38 off for conversion he was 90 mins late, even though 85 mins before he arrived he'd told me on the phone he was only 5 mins away. On arrival he went to great lengths to point out how it was currently idling nicely at correct rpm etc... Oh and could I just re-tap the TPS securing threads, secure the TPS properly and sort out TPS wiring that been hacked about...I'm sure the bloke had had loads of prior grief with it and intended to blame me for any further idle/drive-ability problems. I had a fair bit of grief sorting it out but did manage it.
The chkdsk program is still in Windows, has been around since Dos, dunno if it'll work but I'd probably try it first.
In Windows, run command prompt as an administrator (right click to open and select the admin option).
If you enter 'help chkdsk' a summary of all chkdsk's runtime options/switches are displayed.
Seems entering 'chkdsk g: /f' where g: is the drive (change g to whatever drive your memory card is) and /f is the 'switch' that instructs it to fix errors might work... although I might be confusing volumes and drives.
Or an easier way - File explorer, right click on a drive, properties, tools. But you don't get all the same options that the switches in command line chkdsk provide.
Been a while since I was really into IT and it seems I'm pretty much out of it lol.
Hehe, I've met 2 of you, now after messaging Gilbert for the best part of a decade I know what he looks like.too. Conk nearly as big as mine but I didn't have to admit that... Gilbert I have you at a disadvantage Sir ;-)
Smiler wrote:
Hello folks,
Did any of the attendees of this years summer camp take any photos? My cameras SD card has corrupt and I've lost mine. I have a few low-res copies of some of them that I posted on my thread on the Retro-Rides forum but there are a few missing and I'm trying to write this months (rather late) submission.
Cheers,
Smiler.
Smiler wrote:
Hello folks,
Did any of the attendees of this years summer camp take any photos? My cameras SD card has corrupt and I've lost mine. I have a few low-res copies of some of them that I posted on my thread on the Retro-Rides forum but there are a few missing and I'm trying to write this months (rather late) submission.
Cheers,
Smiler.
Wonder if a chkdsk type program would rescue any pics from the corrupted card? Mind you if we approach diagnosis in the same way as we do most problems - Was the card OK previous to taking any pics featuring Gilbert? lol
Sorry I didn't acknowledge your post before my last post in my last Gilbert, posts crossed.
Interesting stuff, so if LRSV will build whatever people want (and probably built the Transit I mentioned) what other one-offs are we collectively aware of?