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'...

Is this another one of those 'An area the size of Wales (and maybe we wish it was Wales)' type scenarios? lol..

Can think about it like this.. If diameter of valve opening is only a couple of inches that's only 3.14 square inches, if temp of gas in the tank is only 10c it's at a pressure of only about 75psi, so there will only be about 235 pounds pushing the whole of the valve away from the tank... and recent temp isn't even 10c. Undo the 6 valve bolts slowly and there'll be enough slack on the bolts to provide space between the valve and tank while still fairly evenly balancing the 235 pounds over the 6 bolts... Then it seems not much of an issue.

But you could avoid the above almost completely, either by running the fuel out by sitting the tank on it's side and driving the fuel away or by slowly venting the gas even if the excess flow valve kicks in and slows venting to a very slow rate. If I ever have to do it I slacken the 6 bolts while the tank is venting, I got used to it a long time ago and it doesn't worry me, but it did the first time and I still don't like slackening the last couple of tank bolts even though I know it'll be OK.

If the pressures involved were CNG like then I'd be more concerned but with LPG we're not really talking much pressure

In most cases like the above I've been laid down under a car fitted with a zero degree tank, so liquid gas has escaped after I've removed the valve. Far less concerns on a 30 degree setup where only vapour will escape after slackening a valve, you're not going to get liquid gas squirting out,..A drop of liquid gas hitting your eyeball and cooling it's surface by about 30degC really hurts, this won't happen on a 30 deg setup if the tank is less than half full because only vapour will be expelled

This may not concern you much if you run the tank on it's side to use up the bottom bit of gas... One of a valve's seldom mentioned safety features is an excess flow shut off mechanism, if you do vent gas to atmosphere it can be quicker to restrict flow using the thumbwheel to adjust flow of gas coming out to the point just before the excess flow valve activates, particularly if your pickup tube is below gas level. Otherwise if you had say 30L of gas in the tank you could have gas escaping to the point of hearing a strong hiss but get up the next morning only to find it's still hissing to the same extent lol... So then you start undoing the 6 hex bolts cross pattern until you're down to only 2 opposing bolts sealing the valve, which can be a bit of a worry the first time you do it when you know there's still a fair bit of liquid gas and pressure in the tank and the next move will involve breaking the seal... but it's not so much a concern when you've done it a few times. Don't be worried if you need to undo the valve bolts with gas in the tank, if it all seems to be happening too fast etc you can always re-tighten valve bolts, don't be too worried about hissing or cold it isn't that bad. To prevent the car interior stinking you can refit or at least rest the tank valve area cover so most escaping gas goes outside the car rather than inside.

Anyway, your valve might have a pickup tube for a 270 height tank yet, anyway you could probably avoid most of the above running on LPG with tank stood on one side.

Hehe..

If replacing the lines with Faro you could temporarily fit just the line to the engine making it quite a bit longer at the tank end than you need, and since you'll be shifting the tank anyway you could temporarily stand the tank on it's side valve end down... should allow driving on LPG to get more of the gas out before you take the valve off. Faro ends are all re-usable.

Bit of an aside... Many years ago I converted a limo for a company in Birmingham, I did the engine first and was completing the tank install when I broke the multivalve. The firm needed the car back for the weekend and at the time I didn't have many spares around (certainly not a tank diameter specific mulivalve) so I called around local installers to see who might be able to sell me a suitable valve... A 'done in a day' firm in Leeds who at the time fitted 'Aldesa' gear said I could buy a valve from them, so I went through and bought one from them at a price they'd inflated, and this turned out to be for a second hand valve (could smell gas on it). Still I bought it and fitted it and all seemed well, until the limo firm said they could sniff gas after parking the car up... So I bought another valve on the Monday which arrived on the Tuesday and I went to Birmingham to change the valve, which I found to be leaking from it's PRV, but their limo storage area was under arches in a kind of massive underground limo storage area so I had to take the limo out for a drive by myself around Birmingham to try to find somewhere to vent about 30L of gas. Luckily it was a summer day... so there were no clouds of gas drifting down the hill on the quiet street on a hill I eventually used.

I once vented (er more like released lol) 100L of gas from a cylinder tank in the yard, but first I made sure neighbours etc were out. There was a fair sized stream of very cold liquid LPG running down the yard for about 20 yards, all the tarmac in the area of the stream super chilled, some of the tarmac (in the yard) broke up. Once all the pressure has gone out a tank (because it's got so cold) you can literally pour the gas out, just that whatever the gas then contacts warms it up until the contact has cooled to the same extent.

Lol 40mm, brains not even working out 270-220 tonight it seems ;-)

Agreed with lines of thinking above, on this design tank and valve it is the pickup pipe length that will make most difference. If the pickup pipe is 40mm too short we would expect 40mm depth of gas to be unusable (at least for purpose of fuelling the engine with a sequential LPG system)... 40mm depth of gas remaining in the tank even when the gauge shows empty and the LPG system seems to have run out of gas.

Yours is a 30degree / internal tank, if this were a zero degree / external tank we'd expect the tank to run dry but fill to be limited to 40mm below the level that it should fill to.

Wouldn't expect the 80% fill to be much affected if yours is 270 tank with 220 valve, just that the bottom bit of tank contents would be unusable... unless someone had extended the pickup tube. On most L322's I've converted I've fitted a 270 height zero degree tank upside down with special upside down Emer valve designed for purpose (and which fits inside a flexible gas tight housing). Emer valves are no longer made so on the last few I've converted I've had to fit an upside down Emer valve made for a 250 height tank, extend the pickup tube and adjust the float a bit.

If OBD live data reads correct and flicking lambda voltages but LPG software doesn't, the LPG ECU isn't connected to lambda.. it doesn't need to be connected to lambda.

Yes, pros sometimes use the same approach you were thinking along the lines of! But since you can use the gas (just that you can only get 35L in the tank) why would you need to vent it's contents? Run the tank to empty, then look into changing the valve.

Does the stamp in the brass (for tank height) read 220 or 270? Should be 270, I can't see it properly in the pic but looks like could be 220, if it is 220 that would affect how much gas you can get in.

If it's a single hole tank the outlet is likely to be M10 unless it has a rather old design multivalve in which case it could have flange fittings.

As said on the other thread make sure your solenoid inlet is M10, the one you pictured could be M10 or M12.

Easy to avoid running pipe close to hot parts on a P38.

Minimum bend radius is pretty tight, obviously better for the 6mm equivalent than for the 8mm equivalent. Based on memory I'd say a bend of 90degrees in about 6 inches for the 8mm pipe is OK. Not as tight as is possible with copper but is a lot more forgiving than copper, a kink will unkink.

4 Hole tanks usually have flange fitting outlet valves that would need an adaptor to use Faro (flange fitting Faro adaptor or flange fitting to olive fitting adaptor to normal faro end).

Can buy all sorts of fittings for 8mm Faro pipe, such as ends to fit in 8mm or 6mm olive joins, M10/M12 thread, straight, 30deg, 90degree, etc.

If I were changing 6mm copper pipe on a P38 to Faro I'd go with 8mm equivalent, especially if the reducer solenoid had 8mm inlet. I very seldom use 6mm equivalent on anything at all... Just converted a Ford 1.6 which got 8mm.

If there's any downside to polypipe at all it's that it won't stand as much heat as copper. Of course we shouldn't be fitting any pipe close to anything hot enough to be a concern anyway but question marks can arise when you have a vehicle with, say, a big back box under the width of a spare wheel well, a heat shield will then usually sit between the well and the back box, best type of tank to fit might be 30deg but even for pipe running above the shield there might be concern if using polypipe. On balance Polypipe is better in most respects, it won't break if fitted between components where there is bit of movement either.

Some of the Cop11 rules for pipe runs seem to make less sense for polypipe.

Usually when we talk about Polypipe we refer to Faro pipe but other brands are also common. Although the main brass part of end fittings will work across brands the end caps and olives are brand specific due to differences in internal diameter vs external diameter.

OldShep56 wrote:

I might see if the nice boys at our local car wash will do underneath mine. They're always admiring the car so let's see how much they like it. They're Iraqis and Afghans so they will do anything for a few bob. lol
Bet they get on like a bomb hehe.

Some great shiny engine bays on here, just be careful if pressure washing or steam cleaning around LPG ECUs, I've known a few get full of water that way. Best advice would be to remove the LPG ECU and gas pressure sensor.

**[BrianH]

Its also worth being aware that some of Admiral's call centre staff do not know what they are talking about with LPG - they will ask for any assortment of random bits of paperwork to be sent in or just say we don't cover lpg cars. I'd recommend hanging up in this case and calling back, hopefully to speak to someone with more of a clue!

That's good advice that would be equally applicable with a lot of insurance companies regards LPG converted vehicles. Customers regularly tell me that someone at their insurers told them they didn't cover LPG vehicles / their car needs to be on UKLPG's database / they need to provide a copy of 'The green safety cert' (LPGA cert which LPGA now UKLPG stopped issuing years ago). Quite often in these cases the same or a different member of staff at the same insurers will eventually settle for a receipt from whomever converted the vehicle / the vehicle has passed an MOT since it was converted / the V5 shows LPG as a fuel type. But some such as Saga, Admiral, Hastings do very specifically want the vehicle to be on UKLPG's database. Never heard of Adrian Flux asking for anything.

As Tinley implied, lots of long established LPG bits / brands seem to have recently been rebranded as Tomasetto, I wasn't aware of this with the Zavoli reducers though, last time I bought one was probably early this year and was branded Zavoli.

For the temp sensor you might as well follow TT' and Gilbert's advice. I expect the brass bit is just a thread adaptor, if it's just in the location of a water temp sensor it won't cause any harm to the reducer to remove it anyway.

If your previous reducer solenoid was attached directly can you use that one's male/male adaptor?

The solenoid in your pic looks like the type that has 8mm inlet and outlet? Shiny chrome outlet and shiny nut at the opposite side of the solenoid? If so you can slacken the nut from the outlet and the solenoid will rotate around the shiny bits to allow orientation of the solenoid and it's inlet. 8mm Pipe fittings use 12mm thread.
Your reducer is listed as having 6mm pipe inlet, 6mm pipe fittings use 10mm thread.

Obviously if the solenoid has 12mm thread and reducer 10mm thread, to connect your solenoid directly to the reducer you'd need an M12/M10 male/male fitting. Male/male fittings come in a couple of lengths, you should really use the longer length with the shiny bits type solenoid because that type of solenoid valve has deep threads. I generally use a bit of gas paste when using a male male adaptor with this type of solenoid too.

Of course, if you have to go from 8mm pipe fitting on the solenoid to 6mm pipe fitting on the reducer, some type of adaptor would be necessary anyway even if you mounted the solenoid remote of the reducer. Easy enough if you had a few bits around, e.g. could just use a short length of 8mm equivalent Faro pipe with 6mm copper equivalent fitting on one end and 8mm copper equivalent fitting on the other but this probably won't help you! However, won't your existing solenoid and male/male adaptor work with the new reducer, or if you want to use the new solenoid won't the existing male/male adaptor work with the new solenoid?

I'll have a look George thanks.

The reducer in your pic (Zavoli Zeta S or Zeta N) is a decent unit but a bad point about these models is that they do come with pressure preset and are not very adjustable away from preset pressure which is 1.4 bar on the S and 1.2 bar on the N. You'd want the 1.4 bar Zeta S for the flow requirement of a P38 but if your injector nozzles are 3mm you'd really want less than 1.4 bar pressure maybe around 1.1 bar..If you do manage to adjust this model reducer from 1.4 to 1.1 bar it's flow ability may go down dramatically (much more than the difference between 1.4 and 1.1 bar would suggest). Lack of pressure adjustment is less of an issue for an installer fitting a new install than it is when replacing an existing reducer because the installer can choose injectors and injector nozzle size to work with the engine for the given pressure. We might assume that the original installer did that, so replacing a reducer that comes with preset pressure like for like should make for good results but the thing is a lot of installers who fitted a reducer with preset pressure won't have fully addressed nozzles / pressure so better results might be had fitting a reducer that isn't so limited in pressure adjustment.Before I could advise fitting a reducer with very limited pressure adjustment I'd need to know spec of your injectors and nozzle size, or at least know how ginj compared to pinj when the old reducer was good and calibration was correct.

Yeh Marty, yours will be truly sequential so your slider should be set fully right. The only real exception for modern AEB ECU's is on a tiny minority of vehicles that do a hell of a lot of petrol enrichment during acceleration (where acceleration is defined the same as in the slider context, i.e. increasing throttle position)... usually dodgily remapped turbo stuff that shouldn't have so much acceleration enrichment if the petrol remap was good. Too lean usually decreases power more than too rich, for much decreased power from too rich you'd probably have to be so rich that if you wound the window down a bit you'd pick up on that eggy smell.

I calibrate and drive at the same time but I'm well used to it and can just glance across... Still I prefer calibrating slow stuff rather than really fast stuff. If someone else drives you need to drill it into them that constant throttle position doesn't mean constant speed / a touch more or touch less throttle means maybe a 1% shift in throttle position not a 30% shift in throttle position / stamping down and then holding full throttle means just that / etc. You'll probably see what I mean if someone else drives! If the driver is uncomfortable holding full throttle etc it's probably safer if you drive. Full throttle doesn't mean full speed, you can slow to a stop and accelerate hard at full throttle without hitting unsafe speed at least for a short while and on some cars you can extend that time by riding the brakes at the same time as acclerating though not to the extent of cooking the brakes..

Sometimes on repair jobs the customer drives but mostly a re-calibration gets done quicker if I drive while the customer sits with the laptop sideways on his knee so I can glance at the screen. I often regret letting someone else drive, many struggle with the concept of constant throttle (not unsafe but makes calibration more of a pain), some seem incapable of steering smoothly round a bend while holding throttle steady.