Misfire on LPG

[TheTree]

Hi

My latest fun is a misfire as soon as I switch to LPG, the nanocom tells me it is cylinder six.

So far I have;

Cleaned the connectors again
Swapped the HT lead
Swapped the plugs between cylinders six and four

Still happens immediately, so I am suspecting a dodgy LPG injector perhaps?

Is there any way to test this?

I have some diagnostic stuff, but I need to identify the correct version of the Land-Renzo Omegas software to use.

Any suggestions much appreciated

Steve

[bee utey]

Sticking injectors can be caused by tarry substances making their way down the rail through the filters. The best way to clean injectors is to remove the affected rail, connect a temporary hose to each injector in turn, fill the hose with throttle body cleaner and use compressed air to flush back through the injector. Repeat until the rail inlet runs out clean fluid only.

Also clean or replace the filters. Some manufacturers recommend as little as 15,000km between replacement, I usually do them at around 40,000km.

Generally if an injector goes open circuit it shuts down the gas altogether as it logs as a fault.

Lastly, I recently acquired a Landi Renzo injection kit with spare injectors and converter. PM me if you want anything.

[TheTree]

Hi

Thanks for the tips, I will do the cleaning routine next.

As far as the filters go, I remember you saying that there are pre and post evaporator filters, is that correct ?

Also I assume that changing the filters is a job for an authorised LPG workshop

Regards
Steve

[bee utey]

Hi

Thanks for the tips, I will do the cleaning routine next.

As far as the filters go, I remember you saying that there are pre and post evaporator filters, is that correct ?

Also I assume that changing the filters is a job for an authorised LPG workshop

Regards
Steve

Pre evaporator filters don't stop waxy substances as they are fully dissolved in liquid LPG, those filters only stop lumps. The post evaporator filters are the ones that need attention in this case and you should be able to clean them yourself. Of course you need to be competent with tools and maybe purchase some new, matching filters in advance. (hint: look on ebay) If you doubt your skills to dismantle things, take it straight to your local authorised gas service person. While it is technically correct that you should be qualified before opening a gas vapour hose, it rarely stops anyone who has a little optimism.

[TheTree]

Hi

I consider myself a reasonably competent mechanic and I am lucky enough to have a mate who did his apprenticeship at Holden, worked as an NRMA patrolman for many years, and now works for Pirtek, so there is no fear or hesitation here

I also have more tools than I can poke a stick at !

I will locate the post evap filters and see if I can pick up some new ones

Thanks again for all your help and advice

Steve

[TheTree]

Hi

I found the filters on ebay and note they say this in the listing

"THESE ARE A COMMON SERVICE ITEM AND IT IS RECOMMENDED THEY ARE REPLACED EVERY 12MTH OR 20,000KM"

Also chatting with my mate he said when he was in the NRMA they were allowed to work on the low pressure side of LPG systems but not the high pressure side

Steve

[TheTree]

OK

The story is that the filter i purchased was 12mm inlet/outlet and the one on the car is 14mm and shorter, see pic.

So we cleaned it all as best we could, the amount of crap which came out of the filter was incredible (see pic) I would suspect that it is the original filter installed 7 years ago !

Bad news is that we fixed cylinder 6 but now 1 & 3 are just as bad.

My feeling is that we are not going to get it clear until I replace the filter and then clean the post filter hoses and the injectors again.

If it is still ****ed then, it's either get the injectors professionally cleaned or replace them

I have attached some pics of the rails, are these the same as the ones you have bee_utey?

Good news is i have the software running and talking to the system

Regards
Steve

[bee utey]

The only difference between my spare injectors and yours is that mine are in blocks of three. However when I unbolted the steel cover plate on the wiring side and the individual injectors came out quite easily, gently levered out. This should help cleaning them considerably. I have 2 sets with my kit so 6 are spare. The one I took out looked very clean.

Oh and the filter element inside the filter cartridge comes out for cleaning, just remove the circlip holding the filter case together.

[TheTree]

Hi

Thanks once again mate, you must let me know your favourite tipple

We took the plate off one of the rails but we were not sure how difficult it was to get the injectors out, so we erred on the conservative side.

I suspect that the post filter 14mm vapour hose is also badly coated, so I am thinking of replacing that as well.

It looks as if Germany is the place to get the correct filter and the 14mm hose, so that is a slightly longer term fix.

In the meantime we will continue to fight the good fight

Regards,
Steve

[TheTree]

HI

I purchased a genuine land-renzo filter from Germany, it will probably take a week or so to arrive.

I will sacrifce my aquarium tube cleaneing brush and use it with some metho on the post evap hoses and see if much crap comes out. If they are bad I will get some new hose from Germany as well.

I am also going to see how much a local place will charge to clean the injectors and rails with the ultrasonic equipment they use.

Steve