GasMan wrote:

If you have a Prins LPG system, there is no map - it bases its LPG injector times on the petrol injector times. However, if the LPG installer has set the Rc wrongly, it will cause these sorts of problems - could be the adaptations were out when they set it up, but they didn't have a tool to reset them?

Good to hear you've got it sorted.

Just about every sequential LPG system you'll see these days bases it's ginj (gas injector pulse duration) on pinj (petrol injector pulse duration) but most have a map. Prins VSI1 is a bit of an exception because unlike most systems it doesn't have an easily visible map but there is still a map if unseen... because the combination of offset and multiplier mathematically describe the same kind of curved multiplier line that other systems have. Egas and some BRC systems are similar in only having a control for offset and multiplier.

Most Prins dealers don't realise this and mess up mapping on VSI2 systems or any other system they try to calibrate that isn't VSI1 or BRC... They don't realise that if they plot points on a graph for a given offset and multiplier they'll end up with a curved line, and if they attempt to calibrate a system that only has the multiplier line or only has a set of boxes for multiplier the positions of the points on the line (or the shape of change of numbers in the boxes) should also be curved.

The shape of the curve should depend on the spec of the engine, the spec of it's petrol fuel system, the reducer pressure and reference pressure, manifold pressure, the spec of the gas injectors which includes the opening time, closing time and flow rate (including partial flow rates when the injectors are partially open during opening and closing).

We can draw a line for any combination but some combinations won't work due to limitations of injectors and/or pressures. With only a couple of controls (offset and multiplier) the line won't necessarily match the ideal multiplier all the way along it's length.

VSI1 won't cut it on a lot of modern engines, which is one reason why they introduced VSI2. The points above hint at why Prins VSI1 installers are so inadept at getting good results when they try to fit VSI2 or any other modern system - bolt on guys not LPG conversion experts, main focus on nuts and bolts not the finer points of correct fuelling.

There is something in it though? People do tend to put in batteries without thinking about battery chemistry but different chemistry batteries do need different charging voltages and unless batteries get fully charged the effective amp-hour rating, cold cranking amps and life expectancy are all lower?

I recently bought some ECU's from Poland, daft of me but I forgot about import tax until the delivery bloke arrived and asked me to pay the extra £60 :-(

Last time similar happened was when I bought some pistons for my boat's 2 stroke outboard motor from the US.

Lambda probe sockets are available, they're a deep hex socket with a cutout along the length for the wire to stick through, they have a hex at the other end so you can use a ratchet or spanner on them. In the past I've cut the wires off and just used a normal socket. Been a long time since I've changed a probe on a P38 though, and don't remember if there'd be space for any of these options on a P38.

I suppose if heat is an advantage there's an easy way to heat it, run the engine. It'll heat the probe up as much as the surrounding area but it would be difficult to prevent heating the probe if you're trying to heat the boss anyway?

Once when trying to undo a probe from a P38 the lambda boss twisted out of the exhaust but I reckon whoever installed it had somehow cross threaded it, it was blowing and soot etc had probably made removal even more difficult by packing out the crossed threads. I know I've done some on P38's that have come out very easy, others very tight, the cross threaded one wasn't going to come out. I've also known them strip threads in the boss on removal.

I've made various tools for removing probes on various vehicles over the years, e.g. for the XJ8 Jags I made my own crow's foot by cutting a slit out of a ring spanner, cut the spanner short (close to the ring end but longer than a crow's foot) and welded a socket to the cut end to allow use with an extension bar and breaker bar / ratchet. Not as strong as a proper crow's foot (the ring spanner isn't as thick as a crows foot and loses strength with the slit cut through it) so has the disadvantage that if the probe is really tight the ring end could open up and slip.. but with the advantages (for the XJ8) of having a longer length from the probe to the bar and having the socket at an angle to the ring end.. perfect for using a long extension and ratchet/bar working from above in the engine bay, there wouldn't be space to lever near the probe itself or working from below and a conventional crows foot would see the extension bar foul the engine or engine bay components working from above but the DIY tool makes it easy to undo the probe working from above.

Passed my test at 17 in 1987 but learned to drive much younger, did a lot of it on 'Shell Island' (campsite) in Wales including towing boats (and pushing boats with a towbar fitted on the front of a Landrover, sometimes towing and pushing at the same time lol), driving a 6ton Merc lorry converted to an RV with boats on tow, etc. Up and down the cliff track, beach launches etc with the Landrover. Dad used to send me off-site onto public roads to nearby towns to buy petrol for said boats before I was 15. Drove tractors and ploughed fields working on a local farm after school and weekends at 15/16. Day I got my provisional I drove to London to deliver an outboard engine dad was selling but I could already drive properly. Only had 5 lessons before passing my test but dad was a club turn / entertainer and I used to drive him to and from gigs so got a lot of practice on unfamiliar roads between getting my provisional and going for my test and he was a good driver/teacher.

Dad's mate didn't even take a driving test until he was in his mid 40's but had owned cars since 17 and somehow managed to get insurance. The first vehicles he drove were the oversized dump lorries they used to dump spoil on pit tips when he was 14. Never even had any lessons, police pulled him one day and found out he didn't have a licence, he wasn't prosecuted but had to go for his driving test, when he went for his driving test the examiner asked him how long he'd been driving and owned cars.. which was around 30 years... the examiner said 'take us back to the testing station you've passed'.

At the other end of the scale my grandad could have been give a licence when leaving the Navy but didn't bother to apply for it after getting home from the Jap POW camp he'd been in for 4 years. Then he set up in business and wanted a licence so had to go for his test. When the examiner failed him for the 2nd time grandad punched him in the face in the car lol. He passed 3rd time...

Missus is learning to drive at the moment. Told her that due to the new rules she can drive to Cornwall with the caravan on the back while I go to sleep... but she told me where to get off (and I don't think I'd sleep well anyway).

I missed this thread or I might have suggested the problem could be LPG calibration.

As mapping LPG systems go they don't get much simpler than on a P38... Was it the same firm you visited that messed up LPG calibration in the first place?

Echo-Echo wrote:

Trawling through this Forum, I've just read this. Could it have been L Jackson, The Rocket Site, Misson, Bawtry, Near Doncaster ? I too went there in Austin the '70s and was intrigued by the range of ex-military gear they had (including a Land Rover on steroids with 900x16 tyres - no, not a 101). I was there for a rear axle for my Champ...

Just seen your post.

It could have been, I'd probably have been too young to take much notice of the name of the place and exact area but I do remember it wasn't far from Doncaster so it may well have been the place in Bawtry.

The warehouse with Landrovers on racking was massive but I was more impressed with the shells etc in the yard!

Marshall8hp wrote:

From memory you have to leave the ignition off for more than 20 seconds so the ECU resets before the pump will run again.

Ahh, my suggestion of turning the ignition on/off a few times before cranking won't help then (unless fuel pressure drops very slowly).

A rudimental check for gas leaking is to squeeze a rubber gas pipe to injectors when the engine has been turned off overnight, if it feels like there's pressure there probably won't be a leak, no pressure means the gas has leaked somewhere and in your case probably into the inlet manifold as Bri said.

If there's no gas leak and if the petrol system retains pressure then check LPG calibration because calibrating the LPG system too rich can cause negative fuel trims which makes the engine run leaner on petrol, including (in some cases) during cranking.

But since leaving a key in the ignition makes a difference it does point more toward lack of petrol pressure. What happens if you leave the ignition on a few seconds, turn it off, repeat a few times before cranking?

Hello and welcome Max.

I have never owned a P38 but have converted a lot of them to LPG.

Others will answer your question about competition between forums better than me but it is my understanding that Gordon and Richard decided to start this forum after experiencing 'problems' on other forums.

I had RAC membership as an extra with my Barclays bank account.

I broke down towing a large caravan on my way to Newquay. To cut a long story short the RAC came out and would have moved the car to Newquay but not the caravan... I had to get an independent garage to move the car and Caravan to Newquay.

I hired a car on holiday in Newquay, after the holiday the campsite allowed me to leave my car and caravan stored there, returned home in the hire car.

Took the advice of a few people on this forum including Gilbert iIrc? Joined the AA, went back down to Newquay in my other car, had a few extra days in Newquay, called the AA out, they moved the broken down car back to home in Yorkshire (took a few days for them to get it back), I towed the caravan back from Newquay with my other car.

I obviously took advantage. I doubt RAC would have moved the car with ruined engine first to Newquay and then come out again and move the car to home even without the caravan... And I needed to be there with the broken car to pretend to the AA that I'd been driving that car in Newquay, so I kept my other car out of sight before they arrived, told them I didn't need a lift home thanks because I'd hired a car, no need to mention the caravan.

I think the AA would have moved the car and caravan, either from the breakdown position to Newquay or from Newquay to home, but not both. Could hardly ask a breakdown firm to move a broken car to one place and then come out again and move it to another place.

Even the 'start' connection at the ignition key switch?

Before I knew problem fuse boxes were a thing on P38s I was called out to a Rangerover specialist to diagnose a problem that saw the engine would crank but 9 times out of 10 wouldn't start, the problem turned out to be due to an issue in the fuse box, the relay that powers the petrol injectors positive wasn't switching and it wasn't the relay at fault. Until then I didn't know that the relay coils got a constant positive and were earthed by the ECU (at least that model/spec P38), seemed there was a break in the fuse box between the ECU negative signal to the relay and the relay itself (iIrc or it could have been the relay got the switched negative but not the constant positive). Anyway I wired up an easy get-around once I'd identified the problem. The P38 was converted to LPG but the nature of the problem was more of a job for an auto-electrician than for myself, but I sorted it anyway and was a bit surprised that none of the staff at the specialists could solve it.

Dynamic tariffs and pay per mile are not necessarily the same thing but if smartmeters in homes had dynamic tariffs (dynamic as in change the cost of charging an EV depending on the time of charging) and cost of batteries came down low enough, then to get around the higher peak time charging cost people could fit a separate battery bank to charge up off-peak then charge the EV battery from the battery bank and charge their EV during peak times at the off-peak rate.. and maybe charge from battery to battery faster than charging from mains to battery.

Will the per mile component be the same price for all vehicles or vary depending on year / make / model / engine size / emissions (or relative to cost of current road tax)?

If relative to current road tax those of us with older vehicles with big engines could still pay less per mile than a newer vehicle of similar spec.

Over the years there's been several times of discussion about doing away with road tax and adding an additional tax to fuel... but can't see that happening because it doesn't allow for all the same big-brotherish type controls.

Notice the steam cleaning effect provided by a head gasket leaking coolant into a cylinder...

I saw this thread earlier today and watched it in case the OP, who has only ever made this one post, turns out to be a spam robot.

It won't hurt to post this now somebody else has already replied lol.

I was aware about nitrogen finding leaks but I thought the main reason it was used to test AC systems instead of air was because air might contain water vapour?

nigelbb wrote:

A few years back I got some new tyres at ATS & they offered for a price to inflate my tyres with nitrogen promising some magical benefit. I declined on the basis that air is about 80% nitrogen already so that would be good enough for me.

Nitrogen is more pressure stable with varying temperature than air, so on race cars when they want to keep tyres at a specific pressure they might fill them with nitrogen. But for a road car if your tyres are getting hot it's probably better that they do get the bit of extra pressure provided by expansion of the air in them?

I know someone who has just used Seafoam in his Nissan VQ35 engine.

He had suffered a blocked cat (common problem on those vehicles) and after clearing the cat debris the engine smoked and the inlet tract in the manifold to one or more of the cylinders on the engine bank that'd had the blocked cat were found to have evidence of oil in them, not to mention low compression on one of those cylinders.

Some suggested that the problem could be stuck rings and that Seafoam might help so he used Seafoam the other day but at the moment the engine still smokes. Some Youtube videos suggest that the engine smokes a lot during using Seafoam and will smoke for quite a lot of miles after using it. Fingers crossed but I don't think it's fixed his problem and probably couldn't have been expected to fix it.

By most accounts though it does do a decent job of carbon removal? Some vids claim even more and show engines that had problems such as sticking hydraulic lifters that were sorted by using it.

If you want to increase range on LPG of a P38 there's always the option of fitting a second (and a 3rd, possibly even a 4th tank).

Adding a single extra tank could easily more than double capacity/range, and you could fit it yourself for around £250... but it would take up around half the boot space.

Triple range for around £500 but not have much boot space left at all.

Maybe quadruple range for £1100 but have no boot space left and lose the petrol tank.. So then it would be monofuel LPG.

Side point - adding extra tank(s) can also increase the filling speed.

I'm not surprised that people don't like the idea of monofuel LPG, I too feel re-assured to know that I can fall back on petrol if necessary.

But I'm also not surprised people don't much like the idea of effectively only being able to recharge an EV at home and at work, not have the ability to fall back on petrol and not have the option of doubling range for £250 or even for £25k.

It would be handy to have the ability to refuel with LPG at home but that is something I could have if I really wanted it or if it was necessary. Even before LPG I could have stockpiled petrol at home if I'd ever felt the need but I never did (although I have stockpiled red diesel in the past!). It is more important to me that I can take my car anywhere with confidence of being able to find somewhere to refuel it close to my ideal route, refuel quickly, has long range, I can tow with it, I didn't have to pay £50k for it, and I don't have the uncertainty of it needing a new fuel tank in a few years that might cost £20k to replace.

I'm not a climate change denier and I acknowledge vehicle engine emissions have played a big part in climate change but the work I've done so far has helped reduce CO2 emissions to the extent of taking hundreds of vehicles off the road while not replacing them with brand new vehicles that were made at the cost of a lot of CO2 emissions. Until electric vehicles have better range and the charging infrastructure is much improved petrol/LPG dual fuel vehicles are still not a bad bet - I am busier now than I have ever been despite BP and Shell pulling out of the market and despite turning down contracts to convert hundreds of taxis.

A lot of EV buying has been company cars for office workers... who have since proven to be able to work from home, therefore it won't matter much if they have a dirty great diesel on the drive or an EV because they won't use it much in future, so why still allow subsidies for them to buy a new EV? If the buyer claims it's for leisure use and they want to use it to visit their remote farm in Scotland from London every weekend then that's their civil liberty and a different matter but an EV less than a Tesla would be a poor choice for that type of use.