Some installers I trust..
Injector cleaning does work and I use it as part of a service. It will only work if the injectors are dirty or gummed up, it will not help if the seals have been damaged. Gummed injectors are most noticeable when the engine is cold
Like Dai Classicswede
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
2 miles A1, 8 miles M62, http://www.Lpgc.co.uk