the combustion temperature of LPG will be lower on a lean mixture, contrary to petrol. So no risk of melting pistons. By nature the combustion temperature of LPG at optimum mix ratio is already higher than petrol, which explains the higher thermal load on valves. Fuel enrichement will not reduce the temperature as there is no cooling effect of petrol.

You biggest worry with running a too lean LPG mix is burnt exhaust valves ;)
I do love the odd occasions when Henery gets technical!
:)
 
I think that was my question :D how much do you worry about it/watch fuel trims etc
If the LPG runs lean then the petrol ecu will compensate and run crap when you switch back

I've never worried about it to be honest, I did map the LPG system to get it back running 100%, when I bought her it would lean out and almost die at over 3000rpm check that the petrol side is running perfect first. Lambda's switching, MAF airflow numbers correct, trims in the right place, all that sort of stuff.
Before doing any mapping work you need to ensure the petrol side is as good as you can get. Then see how it performs as a multipoint system slaves off the petrol side, also worth noting problems with the LPG ECU aren't unheard of.. They can lose mapping info when the battery is disconnected when they're old for eggsample, so if the problem's as simple as that a remap may be an almost total cure (save for the fact the map would be lost next time battery is disconnected). If you have LP issues though it is far more likely there's an issue with the reducer, injectors, pressure sensors, temp sensors, in which case mapping won't fix it but the interface will allow you to see readings and (likely) allow you to switch individual cylinders back to petrol (to find problems with individual LPG injectors) for example ;) ##
 
I've never worried about it to be honest, I did map the LPG system to get it back running 100%, when I bought her it would lean out and almost die at over 3000rpm check that the petrol side is running perfect first. Lambda's switching, MAF airflow numbers correct, trims in the right place, all that sort of stuff.
Before doing any mapping work you need to ensure the petrol side is as good as you can get. Then see how it performs as a multipoint system slaves off the petrol side, also worth noting problems with the LPG ECU aren't unheard of.. They can lose mapping info when the battery is disconnected when they're old for eggsample, so if the problem's as simple as that a remap may be an almost total cure (save for the fact the map would be lost next time battery is disconnected). If you have LP issues though it is far more likely there's an issue with the reducer, injectors, pressure sensors, temp sensors, in which case mapping won't fix it but the interface will allow you to see readings and (likely) allow you to switch individual cylinders back to petrol (to find problems with individual LPG injectors) for example ;) ##
I ripped out my old ECU and fitted a brand new one, all seems ok but runs rich when i switch back to lpg.. will do a calibration tomorrow and see how it goes. Pressure at the injectors seems ok too
 
I've never worried about it to be honest, I did map the LPG system to get it back running 100%, when I bought her it would lean out and almost die at over 3000rpm check that the petrol side is running perfect first. Lambda's switching, MAF airflow numbers correct, trims in the right place, all that sort of stuff.
Before doing any mapping work you need to ensure the petrol side is as good as you can get. Then see how it performs as a multipoint system slaves off the petrol side, also worth noting problems with the LPG ECU aren't unheard of.. They can lose mapping info when the battery is disconnected when they're old for eggsample, so if the problem's as simple as that a remap may be an almost total cure (save for the fact the map would be lost next time battery is disconnected). If you have LP issues though it is far more likely there's an issue with the reducer, injectors, pressure sensors, temp sensors, in which case mapping won't fix it but the interface will allow you to see readings and (likely) allow you to switch individual cylinders back to petrol (to find problems with individual LPG injectors) for example ;) ##
Oh feck, now look what I have done!
Sorry folks!:(
 
Feck off! That word is absolutely and entirely appropriate in that context. You little hustler you!
giphy.gif
 
Oh dear, I really should pay more attention. :(
My discharge letter from the orspital says my CRT & MRI scans (taken immediately after my recent tumble) show "generalised atrophy of the brain parenchyma".
This is an early stage/symptom of Old-timers disease I believe. Feck! :eek:
If they're discharging you, things can't be too bad, i hope? We all lose brain cells once we reach adulthood :eek: what does your doc say?
 
If they're discharging you, things can't be too bad, i hope? We all lose brain cells once we reach adulthood :eek: what does your doc say?
I guess I will have to ask him when I have my next appointment. It may just be that the old grey-matter is shrinking as I age a bit more than is "normal" (whatever that is).
Web searches define it as the pre-cursor to Old-Timer's Ga-Ga-Land. Maybe it takes years and years to progress.
 
I guess I will have to ask him when I have my next appointment. It may just be that the old grey-matter is shrinking as I age a bit more than is "normal" (whatever that is).
Web searches define it as the pre-cursor to Old-Timer's Ga-Ga-Land. Maybe it takes years and years to progress.
Problem with web searches, they usually end up saying the worst possible outcome, though I've heard kayleigh in Facebook is an eggspurt in all medical matters!!
 

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