Hi all,

I've done a search to see if anyone has posted a guide on repairing/servicing dodgy converters but can't seem to find one. I have a 1996 Ford Falcon EF with an LPG conversion (done back when the car was pretty much new). I have no history with the car so can't tell when it was last serviced, but I've got to near the end of the long snag list with the car before I drive it east and now I've come to a potential stumbling block.

When driving along the LPG runs absolutely fine (far better than on petrol - I'm guessing that's because of engine timing and also not having been run on petrol at all by the previous owner - I've sort of remedied that by running it on super petrol with injector cleaner), but after a while of driving the power starts to fail as if being starved of fuel. Having heard from a few people that it's the converter freezing I checked and the unit actually had ice on it! Once it's done this I have to switch to petrol to carry on my journey - not exactly ideal with a long drive across the Nullarbor looming ahead!

The conversion was carried out by Victoria Alternative Fuels (are they still going?) and has a Sprintgas fuel tank and a Nolffe(?) converter. I've recently had the coolant system flushed and a new thermostat fitted, I didn't check the heat of the pipes at the time, so I was wondering whether it could possibly be a blockage causing it?

What steps would you take (if any) to diagnosing the cause of the freezing and how easy are the converters to service yourself? I'm fairly competent mechanically, but is it a case of don't mess with the LPG system and give it to a qualified professional? How much would a new equivalent converter cost?

Any help appreciated - I can provide photos if required but won't be until tomorrow as it's getting dark here in WA now.

Cheers,

Andy

P.S. Any recommendations for LPG servicing in Perth or surrounding area and suppliers of gas converters, servicing equipment?

Last edited by andyhardy on Sat Jan 16, 2010 1:20 pm, edited 1 time in total.

have you checked your water levels?
or if any of the water lines to/from the converter are blocked or creased?

the only time mine has frozen is when the car was low on water.

check the water flow to and from the convertor...

find the hose that is the outlet from the conv....with engine running pull the hose off and check water is flowing out of the convertor....do this for the inlet hose as well....

convertor could be blocked or a hose or a few other things

Start by taking pics of where the water hoses connect to the converter and the orher end of these hoses.
It could be a few reasons and this could narrow it down to help answer your question.
And also how old is the system?

Thanks guys,

Those are all good first steps for me to be getting on with. As for the age of the system - it's 1996 ( ) but it worked well for a while.

The water levels are tip-top - the hoses appear squidgy (they've not hardened) but there could always be a blockage inside.

I'll take pics of it, but I assume the hose from the thermostat housing is the inlet hose and the one appearing to loop around the engine (I assume to the heater matrix?) is the outlet hose?

I'll take the pics of the engine bay and LPG setup - there are a few things that I'm not too happy with install wise but it seems to work fine and does until it freezes over!

Will take some pictures tomorrow after I finish work and do some work on it on Saturday day time.

I'm on a budget (I'm a British backpacker for my sins) but am prepared to spend money on getting this right as it's going to save me a shedload on fuel going east (all the time I can get LPG anyway!).

Thanks again for the help,

Andy

P.S. I did have an issue with the engine overheating when I first bought it and had the coolant system flushed by a garage and new thermostat fitted (old one had been removed). The engine now runs pretty hot (near and around the O on NORMAL!). This doesn't seem right to me!

There is the problem, the two stage thermostat needs a mod to allow coolant flow at all times to the heater. Take it to a gas shop and get it modified. With it running hot this will make the problem worse that would need investigation as well.

cant you just buy the right one?
shouldn't need to modify it...
i got a new one in my car and never had an issue.
might just be the way yours is setup though

Depends where the converter hoses are connected.
I believe the AU thermostat has no tail to shut off the heater hoses.
My car is not affected by this as mine has a t fitting where the ecu temp sensor is.
This is why I asked for pics. Your car is running rather hot and may have a blocked radiator.

most EF's have the convertor hooked up to the small heater bypass outlets, down under the untake manifold, not T'd from the thermostat housing like yours.,..

I just fixed my convertor freeze prob today by re-routing the hoses completely....i added a T piece at thermostat housing temp sensor (like yours) and a T piece in the heater return hose, ran 5/8 hose to and from the convertor (replaced the 3/8 hoses)...

the problem causing the freezing on mine was a blocked heater bypass pipe....( i have seen this before on an ED i owned and fixed it the same way....

OK - thanks for the replies guys, I didn't get a chance to take pictures last night as beer was calling, but am back from getting a couple of new tyres now so will take some pictures for you to comment on.

Cheers,

Andy

Here are some pictures - I'm going to have to let the engine cool down a bit before I can start looking further at the back of the engine bay as it's still pretty hot from my morning's journey.







Let me know if there's anything that looks remotely dodgy - sorry about the state of the engine bay, I intend to clean it up once the car is running right, this is the last major problem with the car to fix (although as someone said, I probably need a new radiator as well! )

Cheers,

Andy

I've pulled the bottom hose off the converter which I believe is the supply one and a load of clean coolant came out. I'll try the top hose tomorrow and run the engine to see if the coolant is making it through OK.

I noticed that the old thermostat had been cut, I assumed this was to stop it from overheating (possibly because the rad is bunged up? seperate problem so I won't dwell on it here) but perhaps it was because they had problems with the converter freezing when the coolant is up to temp?

I've sat the car on idle on my driveway running on lpg and the converter is staying hot, but the engine never seems to get up to temperature to get the fans kicking in (and perhaps therefore not kicking the thermostat open?), so perhaps it is something to do with the cooling loop through the converter from the thermostat housing?

Another potential cause (I'm really clutching at straws here) is that the converter is upside down (the 'Nolffe' logo is upside down) meaning that the hoses will be swapped, would it be worth swapping the hoses around on the converter as I saw from another user that they did the same thing and it cured their freezing problem?

I'll give some of these things a go tomorrow! Any thoughts and input appreciated!

Cheers,

Andy

The tail of the thermostat is your problem.
Get a AU thermostat (no tail) or cut a chunk out of your current 1.
The tail is shutting off your heater hoses when it gets hot.

That's what I'm thinking - so basically I need to get the thermostat from a Ford Falcon AU model? What years/model would that be so I can get the right part from somewhere like Supercheap tomorrow?

Cheers,

Andy

Check out this thread
fordmods-technical-documents-diy-f38/tickford-lpg-system-t26831.html