Series or parallel plumbing might be as broad as it is long (probably a pun in that somewhere).. On the one hand if the heater circuit won't flow much volume but has a lot of pressure then series plumbing might be best, on the other hand if the heater circuit will flow a lot of volume but doesn't have much pressure then parallel plumbing might be best.

Seems in practice on most vehicles the heater circuit would flow a fair bit more water if it weren't for the restriction imposed by the components external to the engine (matrix and reducer), so in the case of series plumbing this would point to the matrix affecting flow through the reducer and the reducer affecting flow through the matrix. But on the other hand in the case of parallel plumbing the heater circuit won't flow so much more total water that the matrix / reducer won't each get less flow.

Parallel plumbing may have become the norm because there are plenty vehicles which shut off flow of water through the matrix when the heater is turned fully off or set to the full cold position (like the Honda CRV I'm currently converting which has a mechanical cable'd flow shut-off valve in the engine bay, BMW's and modern Jags that use electronic flow regulators to driver/passenger side individual matrix's, Merc's that use a pulsing solenoid to restrict total flow, some vehicles including some Mercs/BMWs have an electric circulation pump to aid flow at low rpm and can even allow the heater to work for a while when the engine is off). Any vehicle that has such flow metering valves / shut off valves has to be plumbed in parallel.

For sure if we're finding the heater doesn't work as well with one route of plumbing we can take the other route but I don't think it's clear cut. I haven't noticed a drop in heater regardless of parallel or series plumbing on a P38 but that could be because I haven't owned one! Different model 'factory fit' vehicles even from the same manufacturer (eg Vauxhall) and with the same engine / heater matrix use series or parallel depending on the specific vehicle model and year. I have 'repaired' some factory fit Vauxhalls that wouldn't run on gas because the heater matrix was clogged, obviously these were plumbed in series. Dunno what could be read into this but on vehicles that have a heater matrix in the front and another heater matrix in the back (such as my GrandVoyager) the matrix's are plumbed in parallel... But for sure my heater gets hotter just after the throttle has been blipped (rpm increased) than when the engine is sat at idle and I put this down to a flow thing (water pump speed increases with rpm).

Whether series or parallel plumbing is best might depend on all of: model of vehicle, type of reducer, condition of components (e.g. partially clogged matrix or reducer). Series plumbing does bring about the question of whether the matrix or reducer should be first in line for hot water and how hot the water will be to the second component in line under various conditions.

Gilbertd wrote:

I would hope, on a 2002 Thor, it would be sequential, anything earlier would be a nightmare on something that age.

Yes there'd be more negative implications fitting less than sequential on a 2002 P38 than on older models. Because of that and also because the sequential system is likely to be easier to repair I'd hope it was sequential too.

I didn't realise it was a 2002 model, did have a look at his earlier posts (mostly to see if there was more info on type of system), now realise I could have just looked at his vehicle list and seen the VSE is 2002...

Gilbert knows this so this for others info - Etagas is multipoint but isn't sequential. Etagas would have most of the same drawbacks (related to not working as a slave to the petrol system) as any of the other none sequential systems. It is possible to get around the additional issues that arise from fitting any type of none sequential LPG system to a more recent model P38 by adding an AEB OBD Ufix but this still wouldn't make for an LPG system as appropriate as a sequential system. Ufix's read petrol fuel trims from the OBD port and feed an emulated lambda signal back to the petrol ECU to keep petrol fuel trims at zero when running on LPG. But it's unlikely a Ufix is fitted and, depending on year the VSE was converted, unlikely anything less than sequential was fitted. A Ufix isn't necessary at all if the LPG system is sequential, if a Ufix was fitted with a sequential system it would be a sever detriment rather than a benefit.

Best to ask at this point if the Tartarini system is a basic mixer system, Tec97, Tec99, Etagas or a sequetial system?

Most LPG vaporisers use 16mm 5/8" water connections but some vaporisers (including some Bigas vaporisers) use 10mm water hose. If the reducer uses such small diameter water fittings it would of course be best to keep the reducer plumbed in parallel with the heater matrix.

It's unlikely water hose was that stiff when fitted, best advice would be to change any pipes that have gone stiff. I've seen some so brittle it was easy to snap them like a twig... This can happen if gas hose is used instead of water hose, if water hose isn't compatible with the type of coolant, or if hose has been subjected to carrying exhaust gasses (HG problems etc).

Side point - Some of the Bigas 'twin' sequential reducers (effectively 2 reducers bolted back to back using a common water circuit and gas feed but with separate gas outputs which are then usually 'Y'd together) use only a single 10mm water feed. I suppose we could work out the flow rate of LPG needed to produce 400bhp and the cooling effect of vaporising that flow rate of LPG, could compare that cooling effect to the heat stored in water and the water flow rate through the 10mm pipe.. it'd need a greater flow rate than straight calculation would suggest because the heat exchange won't be 100% efficient. I know in practice on a lot of powerful vehicles the 400bhp reducer with 10mm water feed does seem to drop in temperature more than most reducers (with 16mm feeds) when pushed to flow a lot of gas continuously.

No easy way to tell whether they're 2.5 inside, You could just drill the nozzles out anyway.. If they're restricted to around 2.5 inside and you run the same map it won't run much richer than now but if they're closer to 3.0 inside you'll have to lower the numbers in the map, which could avoid your problem.

Or you might want to come back with the info I asked for a couple of posts above first, chance you could just up reducer pressure instead of drilling nozzles out.

Agreed with the latest 'depends largely on the installer' points above.
Gilbert's 19:38 post and my 20:12 post will have crossed... Yeh I'd forgotten that's the way it is in Italy... so as Gilbert said what this means in practice is manufacturers who produce bits like injectors and reducers (but not electronics) putting their stickers on electronics produced by AEB, sometimes putting their stickers on injectors produced by some other firm.

Yeh for sure Matrix XJ injectors would have been better for outright longevity over most others but that's with the benefit of hindsight... Not many vehicles will have been around that had done 100000 miles on any injectors so it wasn't known that Matrix XJ's would be so reliable. Besides the Matrix XJ's there were also Matrix HD's, the latter tended to go down more often than most other injectors (mostly built in temp sensor going wrong but I received quite a few where one channel was dud when brand new). Got to take it all in context too - back then LPG conversions were considered a bit differently by most... these days it's more expected that the ECU will be one brand, injectors may be another, reducer may be another but back then mixing brands could be considered negatively (even though in reality most ECUs were the ubiquitous AEB unit etc), not least because most installers would stick to their usual brand of boxed kit and tell customers that mixing components wouldn't work or shouldn't be done. Sure you could get around that because Matrix injectors would come wearing the Zavoli / OMVL sticker, but around that time I sometimes converted over 10 P38s in a straight row, some customers came to me for an OMVL system fitting because their mate's P38 that I had converted with OMVL gear ran so well and wanted all the same parts fitting on theirs. I was one of the first UK installers to mix components, I started doing so on the most demanding vehicles first, outcome being that all my customers were happy (since OMVL were great except for on the most demanding stuff, Matrix good on all stuff). There's also the point that if injectors lasted say 120000 miles (say OMVL or Matrix), which person is going to be happier replacing their injectors like for like at that point (OMVL £80 total, Matrix £320) to be good for over another 100000 miles.

Back then (2006) AEB based systems were generally sold as boxed kits, Zavoli and OMVL both systems that were sometimes supplied with Matrix injectors rather than respective own brand injectors. I used to fit mostly OMVL gear, sometimes I wasn't even advised by the supplier that they'd be sending Matrix injectors rather than OMVL injectors and there was no difference to me in cost. Back then most engine bay components were around double today's prices but Matrix injectors were probably just a bit more expensive than they are now. I didn't fit many Matrix injectors on P38s, instead I horded them to fit on vehicles that could make better use of the better Matrix injector performance ;-) No downsides for the customer because by that year OMVL injectors were also very reliable, they were always well on top of the job for a P38 and in any case the customer would have paid his deposit expecting all OMVL bits... But lots of positives for the more demanding vehicles that then got Matrix injectors rather than OMVL injectors. In 2006 I'd have converted the P38 with either OMVL or Matrix injectors for about £2k, the old spec OMVL reducers were about on par with Zavoli reducers for reliability but OMVL reducer would have been far more on top of the job in terms of gas flow ability.

AdamElphick wrote:

I have had very reliable service from my ancient Zavoli GE system on Michael. Apart from needing filters and an age related leak sorted it's been pretty good..... as there are newer versions I am sure they would be as good.

Well, Zavoli ECU's are fairly generic AEB ECU's so no problem with reliability there, Zavoli reducers are OK, Zavoli own brand injectors not great but sometimes they were fitted with 'Matrix' injectors which really are good.

Gilbertd wrote:

Of course, your third option would be to get it to Simon and see what the actual problem is, at least then if it can be saved and won't cost too much, you'll know what bits to change.

I meant to say earlier in the thread - thanks for the recommendation Richard ;-)

Impco is an American brand, it's good quality expensive stuff but they only make mixer systems. Most useful for converting big carb or big throttle body injection engines like old Yank V8s. Depending on the type, unlike most European mixer systems Impco often have serviceable parts inside the mixer itself such as diaphragms (in contrast most mixers are effectively just a machined metal orifice, no moving parts). Imported vehicles LPG converted in the US using Impco gear often have US brand closed loop electronics fitted which usually goes wrong before the actual Impco stuff, if such closed electronics goes wrong it's best to replace that with European spec stuff where possible (not possible with all types of Impco). We don't see many vehicles converted in Europe using Impco gear with closed loop electronics fitted.

It wouldn't be much of a problem to wire either of those systems in correctly, it could be a problem to get them running properly after you'd wired them in correctly.

Not saying you need to buy all new stuff, that King system wouldn't be a bad bet since it comes with the tank and would also have the advantage of being similar to what most people here have and are familiar with. I'll be around on forum but when I'm not others could help you with the King system, probably not so much with BRC or Prins. So/so value considering it's second hand but the parts should be as good as new and would be a way of saving money over new.

Gilbertd wrote:

If it's this one https://www.ebay.co.uk/itm/Range-Rover-P38-4-0-4-6-Thor-Multi-Point-LPG-Gas-Kit-Full-Set-Up-99-02-Prins/302412202111, I'm not sure where Prins came from. It's a King ECU and OMVL injectors but I can't make out what the reducer is from the pictures but it looks like it may well be OMVL too. So nowt Prins about it at all. Although it is the same seller that sent me different coloured seats to the ones shown in the picture on the ad and sent you an Immaculate bonnet that wasn't......

No Prins bits there lol... Reducer looks like a Tomasetto model, I'd guess Arctic as gas enters from the side unlike Alaska and it doesn't have a gold coloured rear unlike Antarctic. Would expect an Arctic to struggle to flow enough for a P38.

Gilbertd wrote:

Avoid Prins and BRC for the same reasons your Landi isn't too clever. Very limited injector options (only the ones that come with it) and, limited software availability (if at all in the case of Prins).

Agreed, I wouldn't recommend either of those especially as a DIY install.

Just to add to that - I expect BRC software is now easily available since Tinleytech are the new BRC supplier and won't be as fussy as the old BRC GB used to be... In the days of BRCGB I believe I was the only installer not to have gone through their 'training' (which BRC installers paid £1000 for) who BRC GB would supply and allow access to their software downloads.. probably because they knew I could sort BRC problems when their local BRC installers couldn't ;-) I know they had a board meeting in which they decided to allow me access even though I hadn't paid lol. Out of the two (BRC / Prins) from a calibration point of view it is far simpler to switch a Prins system from one model vehicle to another provided the Keihin injectors are a good match for the engine spec (BRC a bit more forgiving in this because can work at a wider range of pressures than Prins). I could give you Prins VSI1 software and a valid user key (necessary to make any adjustments) or any of the BRC software (except the latest 'BRC calibration tool', which I have, but which needs a unique activation key which tallies with some unique aspect of each laptop such as I expect it's mac address, so only BRC or TTech can provide the activation key). Both Prins and BRC systems use their own unique interface cables, you can buy clones but they don't always work. For example there are about 7 variants of BRC, the proper BRC cable works on all variants, the clones are usually variant specific. BRC can be a minefield to set up, most variants don't use a runtime vac sensor but need an installer spec vac sensor for initial calibration, some variants use 3 files to setup (firmware, methodolgy and calibration) to suit the vehicle for aspects such as extra injection filtering. There's BRC Sequent, Sequent24, Sequent24MY07, Sequent56, Sequent56MY07, Plug n Drive, Sequent32... Each uses different software
, is setup differently, some are even wired to the car differently (e.g. Seq24 preMY07 cuts the common positive to petrol injectors, no petrol injector breaks as such, just one wire to each petrol injector.. and it's incapable of true sequential operation because it batch fires LPG injectors in blocks of 2).

Gilbertd wrote:

I seem to remember, from the brief look at it at last years summer camp, that it's one of the Landi Renzo systems that uses an AEB controller. If it is, swapping for something like the King that has loads of different injector options would be feasible and would't require a complete re-install. Get as much info on it as you can and ask Simon if it can be made to work with the IG injectors or if you will need to change the controller too.

It it's post LandiRenzo 'IG' system (and if it has pulsed injectors it will be), if it's injector coils are close to 3ohms (not closer to 6ohm like early 'slow' spec injectors) then injectors could be replaced with a different type. If injectors are the only issue this would be the cheapest immediate fix but is it worth fitting an 'electronics' kit (ECU, loom, pressure sensor, switch) anyway. As Bri implied, ECU's can go wrong (still work but forget mapping / drive injectors peak/hold incorrectly), pressure sensors can go wrong and it could have an unusual / increasingly difficult to get hold of pressure sensor.

Most LandiRenzo software is very similar to generic AEB software, seems like just menu positions have been swapped around to give it a more distinct feel.. but not even to the extent of Tartarini (Tartarini is definitely generic AEB compatible with the exception of using a different spec interior switch and different spec temp sensors).

Not sure if Landi (system) took over from the LandiRenzo systems, they're very different though.

Over the years Landi Renzo did make some unusual systems, though as Gilbert said some are compatible with the generic AEB stuff.... But don't presume just because a generic AEB type ECU (AEB2568) would fit the connector for a Landi Renzo system that it will be compatible - some may fit but use a different pinout on the connector.

There are a few very different AG systems... Some are compatible with different injectors etc, some are real oddball systems that a separate ECU / injector emulator. The latter (also known as Teleflex) you can't even calibrate because the ECUs were either mapped at the factory or the installer downloaded a map direct from AG and the maps are no longer downloadable, no manual mapping options in the ECUs at all. I have an interface and software but it's only really useful for checking pressures (or rather confirming suspicions of a broken pressure sensor). I have a few second hand spares for them including injector emulators, sensors, injectors etc, (no point fitting an ECU unless it came out of the same model car) but I wouldn't even advise playing with one that seems to be broke unless it's something very simple like a fuse lol.

Autogas2000 in Thirsk are a distributor for Landi but not for LandiRenzo. They were never great at installing but used to have decent and helpful staff (for their trade customers when they were a bigger supplier, as well as for their conversion customers)... but they seem to have gone downhill - This year I've converted over 20 Nissan Elgrands, they converted a few before me but made a real balls of them. Some of their customers took their cars back many times but all they did was plug the software in and change a few numbers in the map, eventually fobbing the customers off with a massively compromised install. I had the software for Landi but didn't realise a new version had come out in April2016 or that newer ECUs running newer firmware needed the newer software... They gave me the newer software (seemingly grudgingly) and I went on to sort out the problems on cars they'd converted... cars that basically were almost undriveable on LPG until I sorted them. So bad that is was probably just as well that they'd set them up to switch back to petrol at high loads and even switch back to petrol below 1300rpm because they were incapable of even idling properly on LPG!. One guy used to switch his car back to petrol for town driving or the engine would surge in rpm massively as it continuously switched between petrol and LPG at around 1300rpm when he was setting off (or particularly when reversing). All running nice and smoothly without using any petrol after I'd fettled them ;-) Not just a calibration problem though, they'd fitted massively undersized nozzles and the Landi reducer isn't adjustable away from 0.9 bar. Even after I'd fettled them they're still compromised a bit because of the long pipe runs they'd used and even with the bigger nozzles I drilled out the injectors won't flow enough to run totally on gas flat out high rpm - I could have sorted all the problems but customers wanted to keep costs to a minimum.. can't polish a turf.

Yes, if we made a line from the load numbers in the AEB system map table we'd see how the graph sloped down toward the high load range. If we only plotted the graph for closed loop conditions we could imagine extending the graph for open loop high load conditions and using the numbers from the imagined further plotted points for the open loop area of the map the engine should run similarly as rich on LPG under high load open loop conditions as when running on petrol. And/or we can monitor lambda and Ginj when adjusting map numbers, lean the fuelling to the point lambda voltage comes down to say .6v equivalent (for a 0>1v probe) and increase the map numbers until fuelling should be some percentage richer, and/or we can use seat of the pants. I use all the 'ands' - the petrol system goes rich to varying extents on different model vehicles and on some the mixture goes so rich on petrol that to go similarly rich on gas would provide less performance while using more fuel as such a rich mixture is more likely to spoil volumetric efficiency on gas while a rich mixture on gas (even for same airflow / VE) isn't as likely to give the same performance increase on gas as on petrol. If the exhaust stinks when you boot it on gas it's likely to be way too rich (window open test). We still want a rich mixture on gas when you boot it but sometimes seat of the pants best response is when lambda is within range of a 0>1v sensor at about .8v or not much richer than that. Always bearing in mind that a rich mixture will speed up the burn so leads to cooler running valves and means there won't be as much remaining oxygen after the burn which in conjunction with valve heat can lead to valve wear... so we err on the side of caution between seat of the pants and rich. When you're just cruising or particularly if you've been sat idling for a while gas temp will be higher than it is after a sustained high load but the temp sensor can take time to reflect the actual gas temp... If you set high load mixture when gas temp is reading hot and don't recheck high load mixture after sustained high load use the mixture could be leaner after sustained so it's a good idea to give the car some stick and check high load mixture when gas temp reading has responded and reflects the cooler temp of the gas. Gas temp will always be cooler when using more gas because there's a combination of more cooling from turning more gas from a liquid to a vapour and the gas spending less time in the reducer being heated (if the reducer acts as a heat exchanger it becomes a comparatively smaller heat exchanger the more gas that flows through it). The fastest responding temp sensors tend to be those fitted in the same unit as an inline pressure sensor (using a sensor like those fitted in air flow meters directly in the gas flow), the slowest tend to be those simply screwed into a metal injector rail where the sensor itself isn't actually in the gas flow (picks up heat of the metal rail rather than gas temp).. response ranges from a couple of seconds to a few minutes.

Would need a bit of info to be able to help from here... Pressure, Pinj and Ginj readings for all of idle, moderate load and high load. Does reducer pressure fall away at high load high rpm? What reducer do you have?

See if the switch flashes when you boot it...

What are the numbers in the map?

Don't need a wideband sensor but it helps to be able to monitor fuel trims and lambda readings, so an OBD scan tool that can show live data is handy.

Beeping and switching back to petrol when you boot it means the reducer pressure has fallen away so the system switches back to petrol thinking you've run out of gas.

Switch flashing without beeping when you boot it means the pressure remains high enough but the system has momentarily switched back to petrol because it has sensed gas injector pulse duration was exceeding available injection window (gas pulse times too long for given rpm).

If the reducer is capable of enough flow both issues could be overcome by increasing gas pressure at the reducer, but then you should recalibrate (full calibration not just the autocal).

The V30's are a good match for Bigas injectors in terms of linearity/speed so are a good stand in for Bigas injectors in that respect, outlet nozzles for V30s are available to suit 4mm pipe so make for easy replacement of Bigas injectors which have 4mm outlets. Bigas usually use 4mm pipe, V30s usually use 4mm pipe, V34s usually use 6mm pipe but it's best to specify pipe you need to connect to when you order V30 or V34 injectors... you probably don't want to have to change manifold spuds and piping when you're changing the injectors.

Linearity/speed isn't the same as flow rate, Bigas injectors fitted with nozzles of around 3mm will flow more than V30's with biggest nozzles fitted, more even than V34's with biggest nozzles fitted. All injectors have an internal restriction (ultimately the diameter of the hole under the plunger but there can be a restriction after the plunger hole too), V30's come in 2 flavours, one flavour has an internal restriction of near 3mm the other has an internal restriction of closer to 2.5mm.... there is no point fitting outlet nozzles with bigger hole size than the internal restriction because the internal restriction will then be the limiting factor in terms of flow.

If you replaced Bigas injectors that had nozzles above 2.5mm you may need to increase reducer pressure to compensate for smaller nozzles or internal restriction of Valtek injectors.

Depending on whether you're using an old version of Bigas software / firmware I might also advise you reset the LPG ECU before running autocalibration (warm the engine, increase reducer pressure and run on LPG for a bit before resetting the ECU, re-enter all basic settings, run autocalibration and manually adjust the map). The old Bigas software / firmware doesn't show reference pressure and it isn't obvious if behind the scenes they use some standard reference pressure such as 1.2 bar regardless of pressure reading during autocal or if behind the scenes they use the pressure read at time of autocal as reference pressure (which would then be stored and used until the ECU was reset).

Also depending on software/firmware, some Bigas ECUs have petrol addition (above a certain rpm and load) set as standard - if your reducer is big enough it might be a good idea to turn off the petrol addition before doing calibration.

Sometimes the transition from running without petrol addition to running with petrol addition can cause hesitation but so too can the transition from running on gas to switching back to petrol (either in case of low pressure or in case of sensing full duty cycle of injectors).

Orangebean wrote:

Nah- more basic than that. Did you spot the staining on the drivers footwell carpet?!

'Heater matrix bypassed'...