Piped in series on my own old Chrysler Grand Voyager because it has a matrix in the front and another in the back (matrix's flow in parallel of course)..The reducer is in series with the joint return pipe from both... Thinking was along Gilbert's lines, I didn't want half the flow through the reducer and one quarter flow through each matrix...

There are a lot of iffs and buts regards temp correction. For starters, it seems AEB don't presume gas temp correction works entirely correctly anyway, because otherwise they wouldn't have thought necessary to have compensation for reducer temperature too. AEB default temp compensation figures are a bit exaggerated and reducer temp shouldn't even enter the equation. On some installs (and where it won't effect neatness etc) I try to fit the gas temp sensor in position where it's least likely to pick up heat from the engine (or radiator) or blown cold by external air while driving. On other installs position doesn't make a great deal of difference... most V8 powered stuff gets hot everywhere under the bonnet anyway. The old advice was to fit the temp sensor as close to injectors as possible, thinking was it is at the injectors where the temperature and pressure of gas matters and gas temp could be effected by pipe temps etc between the reducer and injectors ... But I've come to think that in reality when driving gas is shifting so quickly through the pipes it will have little time to be effected much by pipe temperature / At idle gas is shifting slower but still quickly enough for pipe temp not to have much effect on actual gas temp / Though pipe, injectors and temp sensor are more likely to be effected by under bonnet conditions at idle and with slower moving gas the sensor might be effected more by the temperature of whatever it's mounted in than by the gas. One of the iffs and buts concerns compensation particularly at low pulse duration, because unless the ECU firmware correctly accounts for injector latency and temperature related response, no single set of (default) compensation figures will work properly over all possible configurations of pressure, nozzle size and gas injector pulse duration. I.e. you cannot accurately apply Boyle's law without accurately accounting for how injector response is affected by temperature and accurately accounting for injector latency, but almost all firmware seems to get these factors wrong, so temp compensation is best adjusted on individual installs. But again, not much of an issue on a sequential Rover V8 where pulse duration at idle should be higher than it is on most other vehicles and where the petrol system is very forgiving in terms of fuel trims etc - default compensation seems to work fine on them.

Simon

I can see justification for all above points but it's still true that over 90% of P38s and most other LPG converted vehicles have reducer plumbed in parallel without issues.

Both the parallel method and the series method could mean the heater matrix and reducer each only get half the flow - for obvious reason with the parallel method, the series method can mean twice as much restriction in the same pipe so the total flow can only be as much as the part with the most restriction. Series wouldn't be great with a fairly clogged heater matrix, in fact I have seen certain factory converted Vauxhalls fail to run on LPG due to this problem and during summers have re-piped the reducer in parallel to allow running ob LPG until the owner had the matrix problem sorted (even following matrix repair, parallel can be left in place with no ill effect)..

Which method works best (keeps both reducer and matrix hot) will depend on aspects of the vehicle. Some heater circuits will be capable of flowing a large volume but without much of a head of pressure, others will have limited volume but with a high head of pressure while flow is limited. So, with parallel method and only half as much total restriction, some heater circuits will flow twice as much water in total, meaning a no compromise reducer or matrix flow situation. Other vehicles like some Mercs, intentionally restrict water flow under certain conditions such as engine above idle rpm, seemingly so heater water flow is consistent between idle and off idle, and where you can't tap into the un-metered side on such vehicles series is best. In all honesty as long as the reducer is low enough on a P38 it doesn't seem to make any difference.

Wouldn't want to pipe some reducers in series.. some such as old Bigas only have 10mm water pipe connections...

Simon

The next step should probably be check main live feed and switched live voltages at the ECU when the switch fails to light.

Gilbertd wrote:

Maybe you had an iffy connection on the common supply to the petrol injectors? That would explain the LPG system getting offended and the popping and banging when running on petrol. If you had a high resistance in it anywhere, the LPG system would be seeing something less than 12V so wouldn't wake up and the petrol injectors wouldn't be getting a full supply.

I reckon that's a good call.

Off subject slightly but it' remains an unwritten rule of thumb for installers to avoid connecting LPG ECU's switched live or rpm detection wire to the front cylinder of any bank of cylinders. Not relevant to P38's though!

On ECU's such as Stag and maybe including AEB2568 B suffix the switched live simply throws an internal relay, may be solid state in other ECUs. Main power for ECU outputs (injectors and solenoids) always comes through the fused main battery connection, wouldn't want to draw potential peak of maybe 10 additional amps from the petrol injector live as that could cause problems for some vehicles.

Good that the switch stays lit now, if all other wiring was OK but brown rpm wire was broken would expect the switch to light only momentarily when switched live was 12v.

Measuring voltage between chassis and an earth point can give insight into the condition of the ECU, sometimes voltage here increases when the vehicle is running on gas (when it is powering injectors and solenoids), any such voltage can throw off readings such as pressure / temperatures and can lead to more problematic connection with the laptop.

Sometimes the first sign of ECU trouble is difficulty connecting. Connection can mprove more difficult if the laptop is powered from the car (some earth loop type thing going on?). In some cases ECU's only work properly when they are connected to a laptop, dodgy ECU might benefit from the power connection over the serial link. Again, earthing the ECU chassis can help.

Simon

Orangebean wrote:

Simin- can I assume that any solid black cable is (or is meant to be) an earth?

Lpgc wrote:

While you're under the cover, check the earth wire connections in the loom under the cover are all good.
Simon

Yes but watch out for the rpm wire which is brown inside a black sheath.

Looks like you've found the connection problem with the broken red/black in the Molex connector anyway.. Well, former problem with connection before the switch wouldn't even light. The later fitted Supaseal connectors are much better than Molex though you do see the odd bent pin.

Simon

Later on I'll see if I can dig out the pinout info I made myself years ago, I've never seen an official or online pinout for AEB systems though.

Probably no need, as only difference between 2568 systems is switch and on later looms the additional wires that can be connected to the vehicle's OBD port. Without re-reading the thread I seem to remember Gilbert saying Vogel fitted OMVL systems, though it is Tartarini 2568s that I'd expect to be maybe different regards the switch.

While you're under the cover, check the earth wire connections in the loom under the cover are all good. Check the pins on the ECU itself aren't tarnished particularly on main earth and main power feed.

Simon

I edited since you quoted me OB, bit more info.

As Jackk and Ferryman said, also there should be a tie-wrap holding the cover to the loom where the loom first enters, probably need to cut the tie-wrap.

Did you get my bit that implied it may have worked OK before if the chassis was earthed before (but now with ECU not bolted to chassis you lose this other earth point). Chassis shouldn't need to be earthed but I've found on older ECUs earthing the chassis can help. When I see a problem like yours I measure voltage between chassis earth and battery earth, any voltage above say 0.5 when all solenoids and injectors are working may imply a problem (which can cause analogues signals such as pressures and temperatures to be read incorrectly), sometimes just earthing the chassis can help.

Simon

Morat's point was worth mentioning when he did, the programs do only show 3/4cyl options unless talking to an 8/10cyl ECU.

As there's power on the red/white, are battery live and earth good? And if so, are those earth connections underneath the ECU plug cover good and no corrosion on ECU pins? Was the ECU chassis previously earthed / is it now?

I'm sure you'll be right on the error codes... Just that a common definition of P1000 is 'check cycle not complete', a constant code on Jags after engine start until cycle is completed during current run cycle even without the battery having been disconnected, occurs on other vehicles when battery has been disconnected. Some older vehicles lose IACV calibration when battery is off, especially pre2000 Jeeps. Could also see potential for airflow versus throttle angle related codes occurring until IACV calibration is relearned.. But is TPS working properly?

Simon

I've had maybe most versions of AEB software work in 64bit, sometimes works properly, sometimes works with issues as described above, sometimes doesn't work. I wouldn't by default restart my laptop in 32bit to run what might be a problem combination of software and OS but have had to do so on many occasions. The 3/4 cylinder scenario reads like a case of worked with issues.

Won't break anything, will pick a few OBD codes up though! Yes you're looking for 12v on that wire as it enters the LPG ECU. You could run the test in reverse, i.e. temporarily cut the wire and apply 12v to the LPG ECU side of the cut, LPG system should wake up and the switch should light for a short time.

I only ever used piggy back looms on a couple of my conversions, they hardly make for a neat install but that aside, the occasional P38 has one injector wired with opposite polarity to the other injectors... not a problem normally but if you use a piggy back loom this means the LPG ECU breaks the positive connection to the effected injector rather than the negative. None of this is relevant to your problems but where it applies - with an older AEB ECU it can lead to the system switching OK to LPG but preventing you from switching back to petrol again, with a newer AEB ECU (that has it's own OBD) it leads to the LPG ECU seeing the lack of injector pulse as an error but you can get around this by disabling LPG OBD error reporting (which also disables the switch back to petrol response), with an even newer AEB ECU that is truly sequential it leads to the related LPG injector not pulsing even if the Hemi tickbox is ticked.

Simon

Richard might correct me on this but would think a 99 Thor might have a 5-0v sensor? Though OBD sometimes recompiles this to reflect 0-1v, but then on 99 year would expect most OBD2 readers to show 99% slow trims anyway...

Can we confirm this is a Prins sequential system, not just a Prins single point closed loop system....? The latter wasn't a patch on R90 and AEB based single point closed loop systems...

As memory serves (and I've used this disclaimer too often recently!) the most OBD2 compatible Rover V8 equipped vehicles I've seen have been post 2000 Disco's with EGR, these do show trims correctly over OBD2 in the usual +-25% range.

Simon

Hypothetically speaking, or speaking from experience though Marty... I'm not guessing, recent practical experience, and I'm not saying it has to be XP to be right... I wish I had taken some screen shots of the weird behaviour of some software, in some circumstances, in 64bit though. Stuff/apparent settings I've seen must have been dropped under development, never seen in any properly working AEB software. I have touched on this topic on LPG forum before and even argued the toss with Tinleytech about it.

Lighter note - Would have thought AEB software writers would have learned how to spell the word 'High' by now.. In every version of software since I've been installing, which goes back to before the B suffix ECUs came out, have spelled 'Higth' hehe!

Simon

Hehe, that's what I thought you meant (without seeing other thread), but then I thought... no wouldn't make that mistake ;-)

Win7 32 bit is a good bet on newer machines, most drivers are usually available (for the laptop itself) for modern laptops for win7. On this laptop I have Win10 64bit, Win7 32bit and XP 32bit.... Never managed to get drivers for XP but no probs for Win7.

Simon

The B suffix ECUs aren't new enough to show individual injector pulse duration in the diagnostics screen.The point I made earlier on these ECUs reading only front cylinder petrol duration applies (nod to one of Orangebean's points above) and perhaps applies even more so than on even slightly later boards, because it also probably isn't possible to switch individual cylinders back to petrol.

On only reading petrol injection from 2 cylinders, no... Because this isn't in agreement with the above / even on the latest ECUs you can set number of cylinders to whatever you want (will just return an error if it doesn't see all petrol injector pulses in this case, unless you set Hemi mode which should really read 'engine is capable of cylinder deactivation'), and also because you should be able to set number of cylinders to whatever you want without even running the engine / without even connecting any wiring except for providing it with main power.

I reckon the reason you only got option for 3/4 cylinders was due to running in 64 bit Windows... Again as said before, the only AEB software that seems totally happy in 64bit are some of the V6 versions and not all of those, this occurrence is far from the strangest I've seen!

What versions of software connected before?

What's this about plug leads?

Simon

Thanks for the info on Dropbox, I realise I was lazy to ask and am getting a bit too much out of touch with computers/IT/internet considering how much I used to be involved with them.

How it should work - Unless the switch lights up the ECU might not talk to the laptop anyway, but if the switch has been lit in the last several minutes it will, or if it has just had main power feeds connected it will. But unless there is 12v on the red/white, while you might be able to connect you won't see any readings such as temperatures/pressures etc.

As memory serves, at least in case of OMVL (and would imagine the same will apply to other AEB systems) there were mostly little changes between most 4.X software, except for pre and post v4.7, where 4.7 was necessary to connect to later versions of one of the suffixes. I'm sure a chat with a tech support guy/ex tech support guy such as Tinleytech/Dai Brace (classicswede on Lpgforum) would clear up what version should work with what suffix, because they will have been used to answering many questions on this specific point.. memory should serve them better on it..

Still, will be surprised if you can't connect using a version of software you already have.

Simon

Head out for a meal? Part timer! I know of one well known LPG installer who was apparently working on a customers car in the adjoining garage while his wife was giving birth in the house (same customer told me)! They are, however, maybe not too surprisingly split up now, and he is no longer an installer. Enjoy your meal mate ;-)

Incidentally, I'm not that used to using Dropbox... Can you browse through files and download other stuff too (not that I have any concerns!)?

Simon

Understood Gilbert, yes pinouts will be same if Vogel is name of a firm that fit AEB, only difference may be later versions have the additional OBD wiring that early versions won't have. Better not confuse matters by mentioning there is also an LPG system called Vogel hehe! But it's true..

I have a fair bit more, mostly oddball stuff, AFC, BRC and Prins, but you do have a good set there Gilbert. Used to be the case that if you bought the full cable adaptors package from WTV you got loads of software with it, a bit more still if you bought the USB version with the couple of extra cable adaptors, but still far from a concise set.

Over Xmas a guy came from Newcastle for me to take a look at his Elgrand recently converted by Autogas2000 with a Lovato system which was running like a pile of s**te. I was surprised not to be able to connect to his system with any version of Lovato software I had, I found out on the day AG2K re-opened that Lovato ECUs changed in May2016 and only post May2016 software will talk to the latest Lovato ECU. Still gave the guy some pointers on what was wrong, such as the 2foot long injector pipes(!), low pressure and system set to switch back to petrol unknown to the driver at idle causing surging as soon as you touch the throttle, but that's a different story. AG2K sent me the software via Dropbox, which I hadn't used for some time, but on using it again I decided to upload all my LPG software to Dropbox. Didn't manage it because my Dropbox was full before half software was uploaded - But I just checked, V3.0 and V4.6 Zavoli software has fully uploaded... I would think one of these versions will work if V6 doesn't, all software is more backwards compatible than forward compatible and V6 is usually the most compatible of the lot. Would expect V6 to work on anything V5 will, but earlier versions can be necessary for early ECU's like B suffix. Links to V3 and V4.6 in Dropbox below, though it looks like you already have V4.6 and 6? Looks like I don't have V5 Zavoli on this laptop either, if I've got it or ever had it at all, but I've never not been able to connect to a Zavoli system using one of the other software versions.

V4.6
V3.0

These are only about 8mb each, could email them if you don't have dropbox.

Try using a laptop running 32bit Windows, even early versions of V6 software don't like 64bit and you can get some very unusual results including options usually never seen and settings such as CNG/LPG reading opposite to how you set them, if you can manage to connect at all..

Simon

Orangebean wrote:

Mine's the 2568B Tony, but I imagine the pinouts are the same if the Vogels is a clone....

Ferryman wrote:

Is the pinout of the AEB 2568D 50-pin socket the same as installed by Vogels? I do have a hardwaremanual with pinout if you wish.
Tony.

If reference is to Vogas it's a completely different ECU, different pinout. I will have a pinout somewhere but it'll be one I made myself and it's finding it... Might as well do as Gilbert suggested though and pull the cover off the back of the ECU plug, there are earth connections between wires in there that can corode. As long as ECU gets battery live and earth and battery live on red/white the switch should light momentarily anyway, regardless of rpm signal, petrol injector signals, etc etc.

You haven't just swapped the two black plugs over that carry the petrol injector signals to the LPG ECU have you...
I can send versions of Zavoli software.

Simon.

No expert on plugs or chemistry but can say what I've noticed, my point of view and what the wider consensus of opinion seems to be.

If you're not sure what make of plugs to fit on any given vehicle, the NGK equivalent to whatever is standard is generally a good bet, not really relevant if NGK is standard.

Single pronged plugs are usually the best bet on LPG, unless standard plug has more prongs. General take on this seems to be that the extra prongs shield the mixture from the spark.

A lot of modern vehicles use platinum plugs as standard, platinum is supposedly consumed during the burn process of LPG because it acts as a catalyst (in the LPG burn process). While I'm sure iridium will last longer than platinum (it's a harder metal), I don't see any problems with platinum plugs in LPG engines, though they do wear out a bit quicker than running on petrol. At school I was taught something that acts as a catalyst aids a process without being consumed itself... and there is platinum in catalytic converters anyway.

LPG needs a hotter ignition source than petrol but I would think any electrical spark should be hot enough, so I don't tend to go with theories that refer just to spark temperature. Where coil voltage is marginal for making a spark jump across a plug gap, a spark may be much less likely to form running on LPG which is a dry fuel compared to running on petrol, so closing the gap is likely to help make for a good consistent spark. For any given condition in an engine cylinder, coil voltage needs to rise to the point at which a spark will jump the gap, so closing gap can also slightly advance ignition timing, I would think a negligible effect. No harm on most engines from using a slightly narrower gap than standard, gap will increase as the plug wears anyway (used to be common to gap points just a bit narrow knowing that soon gap would be to spec). Probably no big gains to be made from different plug types and gaps, as long as there are no misfires.

Used to be fairly common to have to close plug gaps, these days seems much less common, probably due to the vehicles we convert becoming later year models with stronger coils but never had misfire problems with P38s except in cases of worn ignition system components. If I had a P38 I'd fit the NGK's and gap them down a bit.

Having said all the above, I recently did a favour for a mate, changed the plugs on his petrol only Mondeo ST220 with Duratec V6 just for the cost of the bits. He'd had the plugs changed 6 months back and gave me the impression it had run OK since then until recently, so I had to wonder if the garage had changed the 3 rear cylinder bank plugs which is a manifold off job (front bank easy access without manifold off). I drove it in high gear at low speeds high loads to make it misfire and bring on the flashing MIL light, then OBD pointed to misfire cylinder 3, which is the right side rear plug. Getting the plugs out I noticed that 5 were new NGKs but the one with the misfire was an old original type Motorcraft plug. I changed them all for new NGKs, same spec as the 5 NGKs that came out, NGKs supposedly the equivalent to the Ford spec plug. It seemed fairly obvious that I'd found the problem (the plug that hadn't been changed) and I nearly didn't even bother testing it, but I did test it and it still misfired! Then my mate told me he'd had no problems with the car until having the plugs changed last time, and he'd been back to the garage about the misfire twice but they gave up when they found no OBD codes. Now I re-gapped all the plugs (closing) to spec (not pre-gapped to suit the Mondeo) and fitted new leads (his idea). The car now drives well under nearly all conditions but I could still force an occasional misfire at very low rpm near full throttle (few people would drive like that normally), and I reckon this will be due to the NGK plugs not being as good in this engine as the Ford recommended plugs, putting the Mondeo V6 in the same bracket as the Vauxhall engines Gilbert mentioned... but I only learned this while messing with plugs on this car, and since I have converted loads of the same engine in other V6 Mondeos and V6 Jags without having to even consider plugs, can read into this that standard plugs are the best bet on this engine on either fuel and NGK equivalents problematic even on petrol (on this engine).

Simon