Poor quality LPG

[pcous]

HI all,

We had an LPG conversion to our Alphard about 4 years ago. All has run well, but recently we had acceleration/deceleration 'stuttering' problems on LPG, which didn't occur when using the vehicle on petrol. Our local LPG guy said this has become common in this region and, from his research, he believed that LPG supplies across Northern England have been contaminated for several months, which appears to relate to a shipment into Immingham docks. LPG supplies to the Midlands and the South do not appear to have been affected - confirmation that it is, in fact, grim up North! (maybe a tad overdramatic - actually, he said that Scotland is also unaffected...)

As it was explained to me, it appears that dirty LPG results in the gas regulator becoming fouled up, the grime being deposited when the liquid LPG turns to gas. In turn this affects the smooth supply of gas to the engine injecters, and stuttering problems. We've had our gas regulator cleaned out and currently trying to tweak the 'trim' levels for the gas-air ratio to regain smooth running.

Anyone else from this region experiencing problems with LPG?

[Alphard Club]

Not doubting your fitter but have you asked the same question to other fitters around your area? just to confirm this?

[pcous]

Hi Steve,

Yes, I spoke to a second fitter who confirmed that LPG in the region has been dirty. The first LPG converter has a large number of taxi drivers as customers, he'd had seen the problem occurring in a range of vehicles, which alerted him to it being a general problem rather than for specific vehicles. The second fitter agreed that local LPG was dirty, but wasn't able to confirm why (see above post). The issue for vehicles running on LPG, as I understand it, is that there's a gradual build-up of grime in the gas regulator, so it takes time before it becomes evident. Also, there's no way of knowing how long this stock will last, so how long it will be supplied to forecourt pumps in the region...  

[Scott Burton]

I have an Alphard which has a Prins LPG system. Everything was fine until a few months ago when it started to run rough and then cutting out. I contacted my garage who said it was due to poor quality LPG and they’d asked other customers to contact 

 

Mike.Chapman@liquidgasuk.org

 

to log our concerns. The HSE are investigating and until then I need to run on petrol. Frustrating and costly. People will be filing for compensation. I’m based in the West Midlands.

[pcous]

Hi Scott,

 

Interesting to hear that the West Midlands are also affected by poor quality LPG, although it will be frustrating for you of course. Cleaning out the gas regulator improved the general running, but it still stuttered on acceleration and, curiously, on minimal deceleration (eg. when you lift your foot slightly to maintain speed during motorway driving). I assume the gas regulator will slowly gunge up again until the problem's resolved.

 

In the meantime, I'll contact Mike Chapman...

[pcous]

Hi all,

I contacted Mike Chapman at liquidgasuk.org, as Scott said his garage had suggested. Mike sent a summary (see attached) and gave permission for it to be published on this forum. He highlighted that the issue of poor quality LPG affects only the Midlands and North of England. The summary indicates that the Health & Safety Executive (HSE) are still trying to identify what caused the contamination and it doesn't say whether they identified the source, so our local LPG guy's deduction that it was a shipment into Immingham can't be confirmed, and remains a 'rumour' or educated guess....

For our Alphard, the problem of acceleration and deceleration 'stutter' hasn't been resolved since having the gas regulator cleaned out, so the next step is to clean out the throttle body, to see if deposits are affecting the gas-air mix. Hopefully we'll end up with a clean(er) system before starting to travel further afield once again in the Spring. Mike Chapman said he'd put me on the mailing list, so I'll post any updates that I receive.

 

Incidentally, do any of our Alphard afficiandos know whether there's a single or two throttle bodies for the 3.0L V6 engine?

Propane Quality Issues - LGUK.pdf

[Rohail]

Hi,

 

I am from West Yorkshire, I have a Skoda Octavia with prins system.

 

This issue has been going on for over a year now and looks like there is no fix at moment.

 

Every few weeks I have to go to local lpg garage and get the gas regulator cleaned.

 

At some point it does contaminate the Injectors which also need cleaning or replacing.

 

 

[Rojie]

10 hours ago, Rohail said:

Hi,

 

I am from West Yorkshire, I have a Skoda Octavia with prins system.

 

This issue has been going on for over a year now and looks like there is no fix at moment.

 

Every few weeks I have to go to local lpg garage and get the gas regulator cleaned.

 

At some point it does contaminate the Injectors which also need cleaning or replacing.

 

 

 

Hello,

 

Welcome to the Forum.

[pcous]

Hi all,

By way of update, we had the throttle body cleaned to deal with the problem of our Alphard stuttering on acceleration and also on minimal deceleration (eg. when you lift your foot slightly to reduce speed during motorway driving). This only happened when using LPG, not petrol. Our LPG guy suspected the problem was carbon deposits which built up around the rim of the butterfly valve in the throttle body (which opens/closes to control air intake and hence change the fuel-air mix to the cylinders). So, this affected LPG ignition but not petrol because the LPG system is more sensitive to any ignition issues. Has now been cleaned and there's a significant improvement - let's hope it's a job that won't need repeating...

Meanwhile, no update yet from Mike Chapman at liquidgasuk.org about poor-quality LPG in some parts of the country, or the HSE investigation.

[BigNev]

Hi guys!

Hope everyone is well!

I'm a newbie here, we are shopping for an Alphard but not got one just yet!

But we do have 2 cars on LPG - a Chrysler Grand Voyager, family bus, 2005, 3.3 V6 that's been on gas for 9 years, which is the one which is being replaced.

And a Subaru Outback, also 2005, 3.0 H6 (flat 6) that one's only been on gas for 2 years, had it for 5.

Both are BRC systems. Our previous Voyager had an LPG TECH system, the BRC do not seem particularly any better, despite the extra cost.

We are South Manchester, Stockport, and predominantly get our LPG from Cheshire Gas.

With my fingers crossed, up to now not had problems, but I have just changed the 2 filters on the Subaru, engine bay solenoid assembly liquid filter which did look a bit dirty for only 13,000 miles, and the vapour filter between the evaporator and injectors, which is a sealed unit.

I think the evaporator - heats & evaporates the liquid into vapour - is what was referred to as the regulator - but the pressure regulator is on the tank, to regulate the stored pressure down, to then send it to the evaporator at the front.

Anyways, there is clearly a problem with dirty gas that we need to watch out for!

I'll be following this post!

Cheers guys and girls!

Nev

 

[pcous]

Hi all,

By way of an update since my post this time last year, the Health & Safety Executive [HSE] issued a briefing report on this LPG issue in Nov 2024. Their investigation related specifically to forklift trucks which run on LPG; there were several forklift fires reported, which prompted the investigation. As I understand it, a crucial difference between forklift LPG systems and car LPG systems is that forklifts start on LPG, rather than switch to LPG when the engine has warmed - like our LPG system. Problems with starting because of a build-up of residue in LPG vapourisers led to some forklifts being flooded with LPG from repeated attempts to start the engine, which then caused a fire when the LPG escaped and came into contact with a hot surface. So, car LPG systems were not subject to the same risks – however, as we’ve already seen, build-up of residue in the vapouriser caused a lot of difficulties with misfiring and the fuel-air mix.

Here’s my summary: the HSE report confirmed that the problem was confined to the Humberside refinery, which supplies LPG to the Midlands & North England. They said the refinery have made (unspecified) changes that have improved the situation, but not solved it; but because the levels of contaminants in the LPG were less than the threshold which applies to fuel standards (and, therefore, testing), it can’t be monitored effectively unless the fuel standard is changed (which they hinted seems unlikely). So, those of us who fuel our Alphards with LPG in the MIdlands & North will still need to check LPG regulators (or vapourisers) for gradual build-up of gunk, more often than we did before late 2022, but hopefully less often than over the last 2 years….

 

For those of you who like more detail:

 

The HSE report states that Phillips 66, who own the Humber refinery, acknowledged in Feb 2024 that users had reported a build-up of residue in LPG vapourisers. HSE said that, “amongst the many different chemicals found within the contamination, concentrations of (plasticisers and) thiophene and thienothiophene (TTP) compounds were found in the affected vaporisers. The HSE analysis: “identified the presence of the TTP marker chemicals and other similar sulphur compounds, which were present both in contaminated vaporisers and in the LPG refined by Phillips 66 ", i.e. the Phillips 66 refinery in Humberside, “but which were either absent or at low levels in LPG from other refineries/sources…. Phillips 66 have confirmed the presence of these markers through analysis of their own and HSE-provided samples. Their analysis also showed the presence of plasticisers”

They concluded that the “most likely cause of the residue appears to have been related to an increase in the processing of used cooking oil as a co-processed feedstock through the refinery, with specific compounds being found in the propane product, but not impacting on the other products produced at the refinery. Processing of used cooking oil is part of a strategy to meet renewable fuels obligations, reducing the reliance on fossil fuels as part of achieving Net Zero.”

The report also concluded that “the steps taken so far may have reduced the rate at which replacement vaporisers are required… however, as of July 2024, the replacement rate had not returned to pre-September 2022 levels. So it’s better than it was, but not fixed.

In explaining why, the HSE said there was no breach of fuel standards, because: “the residue is at very low levels, which could not have been identified by testing to BS 4250, the standard for this fuel.” And they said that “producing a workable update to BS4250 is not straightforward because the contaminants are at very low levels and the tests necessary to find them are complicated”

The HSE state that they are working with P66 to monitor the effectiveness of the steps already taken and to resolve the issue in the short- and medium-term by altering/improving the refinery process.

For the full report, see the UK Material Handling Association website: https://ukmha.org.uk/wp-content/uploads/2024/12/HSE-Report-on-Forklift-Fires.pdf

Hope this is helpful...

[Rojie]

1 hour ago, pcous said:

Hi all,

By way of an update since my post this time last year, the Health & Safety Executive [HSE] issued a briefing report on this LPG issue in Nov 2024. Their investigation related specifically to forklift trucks which run on LPG; there were several forklift fires reported, which prompted the investigation. As I understand it, a crucial difference between forklift LPG systems and car LPG systems is that forklifts start on LPG, rather than switch to LPG when the engine has warmed - like our LPG system. Problems with starting because of a build-up of residue in LPG vapourisers led to some forklifts being flooded with LPG from repeated attempts to start the engine, which then caused a fire when the LPG escaped and came into contact with a hot surface. So, car LPG systems were not subject to the same risks – however, as we’ve already seen, build-up of residue in the vapouriser caused a lot of difficulties with misfiring and the fuel-air mix.

Here’s my summary: the HSE report confirmed that the problem was confined to the Humberside refinery, which supplies LPG to the Midlands & North England. They said the refinery have made (unspecified) changes that have improved the situation, but not solved it; but because the levels of contaminants in the LPG were less than the threshold which applies to fuel standards (and, therefore, testing), it can’t be monitored effectively unless the fuel standard is changed (which they hinted seems unlikely). So, those of us who fuel our Alphards with LPG in the MIdlands & North will still need to check LPG regulators (or vapourisers) for gradual build-up of gunk, more often than we did before late 2022, but hopefully less often than over the last 2 years….

 

For those of you who like more detail:

 

The HSE report states that Phillips 66, who own the Humber refinery, acknowledged in Feb 2024 that users had reported a build-up of residue in LPG vapourisers. HSE said that, “amongst the many different chemicals found within the contamination, concentrations of (plasticisers and) thiophene and thienothiophene (TTP) compounds were found in the affected vaporisers. The HSE analysis: “identified the presence of the TTP marker chemicals and other similar sulphur compounds, which were present both in contaminated vaporisers and in the LPG refined by Phillips 66 ", i.e. the Phillips 66 refinery in Humberside, “but which were either absent or at low levels in LPG from other refineries/sources…. Phillips 66 have confirmed the presence of these markers through analysis of their own and HSE-provided samples. Their analysis also showed the presence of plasticisers”

They concluded that the “most likely cause of the residue appears to have been related to an increase in the processing of used cooking oil as a co-processed feedstock through the refinery, with specific compounds being found in the propane product, but not impacting on the other products produced at the refinery. Processing of used cooking oil is part of a strategy to meet renewable fuels obligations, reducing the reliance on fossil fuels as part of achieving Net Zero.”

 

The report also concluded that “the steps taken so far may have reduced the rate at which replacement vaporisers are required… however, as of July 2024, the replacement rate had not returned to pre-September 2022 levels. So it’s better than it was, but not fixed.

In explaining why, the HSE said there was no breach of fuel standards, because: “the residue is at very low levels, which could not have been identified by testing to BS 4250, the standard for this fuel.” And they said that “producing a workable update to BS4250 is not straightforward because the contaminants are at very low levels and the tests necessary to find them are complicated”

The HSE state that they are working with P66 to monitor the effectiveness of the steps already taken and to resolve the issue in the short- and medium-term by altering/improving the refinery process.

For the full report, see the UK Material Handling Association website: https://ukmha.org.uk/wp-content/uploads/2024/12/HSE-Report-on-Forklift-Fires.pdf

Hope this is helpful...

 

I could comment on American gas companies, but I won't. 

[BigNev]

Hello there!! 

Well, I do now have a Vellfire!

And it was on lpg when we bought it, saved me a job and a chunk of money too!

I have noticed a drop off of mpg on the Subaru, since the end of 2023, which hasn't changed with new coils, and LPG specific NGK plugs.

The Vellfire runs GREAT, but not had it a full 2 months yet, so I've not had any real opportunity to compare petrol to gas!

How has the situation been with your car?

[BigNev]

American companies..... surely not anything to do with maximum profits....

[Rojie]

6 minutes ago, BigNev said:

American companies..... surely not anything to do with maximum profits....

 

Or taking cost out (without telling ANYONE).

[BigNev]

Surely not .......... hmmm well, actually, I reckon it's more than a little likely!