2005 fitted system - question - servicing & a noisy injector

[GraemeT]

Hi all

I have recently bought a 1997 Ssanyong Musso which has the Mercedes M104 3.2 litre straight six petrol engine. There is an LPG system fitted to the vehicle and some of the fittings on it have a manufactured date of May 2005.

So far all I have done with the LPG is fill it up, replace the coolant pipes to the vaporiser and fire it up. The system works pretty much as it should - starts on petrol, switches to lpg once the vaporiser has heated up (alarm goes off if coolant level too low) and switches back if gas pressure low.

One of the six injectors is very noisy compared to the other five - should that be replaced?

I have no documentation with the system - can anybody advise me as to what sort of annual maintenance needs to be done on this sort of system?

Thanks in advance

Graeme

[Gilbertd]

Annual maintenance consists of replacing the filters. There should be two, one in the liquid phase (often incorporated with the front shut off solenoid just prior to the vaporiser) and a gas phase filter in the hose between the vaporiser and injectors. You will need to identify the make of system to find the correct filters but they aren't expensive. The noisy injector is on it's way out. Again, you will need to identify who made it and for some types you can buy a rebuild kit. Others need to be replaced but it is usually the cheaper ones that cannot be rebuilt anyway.

[GraemeT]

Hi - thanks for the prompt reply - the system is Prins VSI based and has Keihin 'orange' dot injectors. The post vaporiser filter is housed in a VSI unit with an outlet to each of the injector rails that looks as if it will come apart to replace the filter.

I've been Googling and don't see any overhaul kits for the injectors so I guess it's new only?

Likewise the low pressure filter - seems that Prins went over to a sealed unit at some point and I cannot see any standalone filters to fit the older unit I have - does anybody know if they can still be bought or should I look at a new Prins unit (or even a different make)

The liquid phase filter I have ID'd as a Valtek type 07 and Tinley Tech have filters on their site for that.

Graeme

[Gilbertd]

As with everything in this world, you get what you pay for. Keihin injectors are probably the most expensive you can buy as they are reckoned to be so well made that they will outlast the car, no matter how many miles it has done! So unless your car has done Starship Enterprise mileage, you should not have a noisy injector. Hopefully one of the installers that fits these will be along soon with some advice.

[rossko]

I would be suprised at a worn out Keihin, but as there's moving parts some must fail sometime. I've never seen one. If it idles as smoothly on gas as it does on petrol, there won't be much wrong.

I have noticed some Keihin installs come up noisier than others, which suggests there may be variation among batches. Maybe you got an odd one from a different batch. If it touches something external - water hose, etc - it can act as a sounding board. Mounting is crucial to how noisy they appear to be, mechanic's stethoscope tells you more about what's happening inside.

Filter element for older metal-bodied type -
http://www.brcgb.co.uk/drivers-store/service-parts

[GraemeT]

Hi

Thanks for the advice and the link to the filter (I was unable to find anything myself) - both filters ordered and looking forward to fitting them at the weekend.

Thanks again

Graeme

[GraemeT]

I would be suprised at a worn out Keihin, but as there's moving parts some must fail sometime. I've never seen one. If it idles as smoothly on gas as it does on petrol, there won't be much wrong.

I have noticed some Keihin installs come up noisier than others, which suggests there may be variation among batches. Maybe you got an odd one from a different batch. If it touches something external - water hose, etc - it can act as a sounding board. Mounting is crucial to how noisy they appear to be, mechanic's stethoscope tells you more about what's happening inside.

Filter element for older metal-bodied type -
http://www.brcgb.co.uk/drivers-store/service-parts

Late in the day replying to this but spot on advice - after a bit of poking around I found that the bank of three injectors that had the 'noisy' one were mounted on a steel rail bolted directly onto the engine cam cover - they were resonating with the sound of a noisy cam lob directly beneath them - rubber mounting has cured it - thank you

Graeme