LPG

From Holdenpaedia
Jump to: navigation, search

Submission by Jacks
This is a Work In Progress
Additional submissions by named contributors:
Back to the Fuel System Section

Amos Gas mixer installed. This mixer by AMOS in New Zealand is the best mixer I have found by far to suit the 34ADM Weber. I have tried others such as the AMR but these kill performance off quite noticably. This Mixer is good I believe because it acts as a side draft allowing both barrels to keep their exposure to the air flow (unlike others which cover over half of each barrel). With this mixer installed normal performance is felt right up to about 3800 RPM after which (when compared to the cars performance without the mixer installed) the performance starts to taper off.
I have installed some rubber backed Pinchweld on top of the Ford air cleaner assembly to raise the lid and achieve suitable clearance for the mixer. I then use a Valiant Air filter which is a little taller to suit the increased assembly height. This all fits under the standard VK Commodore Bonnet. LMH. Click to enlargen. Photo and info by LMH.


==LPG System:==
Here is a rough guide on the working of the LPG system, if you’re not familiar with the layout off the LPG system or how it works, plus some of the technical names of the parts, then read on as I have compiled some information on the LPG system to help you understand more about it, as it will become more and more used as Petrol prices keep on increasing.
Along with the new $2,000 being offered to offset the cost of LPG conversions, will makes it even more attractive to convert to LPG as most “ Old Holden “ vehicles can be easily converted,

VT Commodore with factory fitted LPG. See Oinks post in the text. Click to enlargen. Photo and info by Oinks308.


===Main components for LPG vehicles:===
A Fuel Tank/Container for LPG to be stored in, including the valves and equipment to allow the flow of LPG as well as entering and leaving the Tank
A Fuel lock valve or filter and fuel lock, to prevent the flow of the LPG when the engine stops.
A vaporizer/ regulator / Converter to vaporize the liquid and regulate the gas pressure in accordance with the engine demands.
A main flow adjuster to adjust the LPG system to the engine.
A Mixer that’s normally fitted on top of your carburetor/manifold to mix the LPG with air which then enters the engine combustion chambers.
A petrol shut off system, is usually in the form off solenoid switches.
VT Commodore with factory fitted LPG. See Oinks post in the text. Click to enlargen. Photo and info by Oinks308.

===Back-flow Check Valves:===
Sometimes called Hydrostatic Relief Valve are fitted between the tanks and the LPG line to the engine. These check valves are designed to stop LPG passing from one tank to another thus limiting overfill.

 

===LPG===
LPG stands for Liquefied Petroleum Gas. LPG is a mixture of propane and butane which is a by-product of crude oil. The mixture is a "waste" product which otherwise would be burned off.
Makes you think, does that mean the cost of LPG is only in the storage and the transportation?

VT Commodore with factory fitted LPG. See Oinks post in the text. Click to enlargen. Photo and info by Oinks308.

===Tank:===

Photo by Jacks click to enlarge

See Picture
Items 1-5
1. Solenoid for Main Line (AFSOD)
2. Manual Tap (used for service)
3. Outlet (feeds LPG system)
4. LPG sight gauge (fuel level)
5. Inlet (filler shut pipe)

The LPG tank is a pressure vessel that has been designed and made in a way for maximum protection. They come in various shapes and sizes, being tested and certified.
It’s imperative that no modification should be done on the vessel at all.
If fitted inside a vehicle extra precaution must be made so as objects being carried in the vehicle will not damage the tank or its fittings.
It is Law that the tank is tested every 10 years or when the vehicle is registered.
Photo by Jacks click to enlargen.

 

===Filling the LPG Tank:===
When you fill up the tank (via a filler valve) the LPG that goes into your tank is fed in under pressure. LPG is stored under pressure to maintain it in a liquid state.  This pressure negates the need for a fuel pump.  The pressure causes the LPG to feed into your engine as required. The engine fuel lines are taken from the bottom of the LPG tank which ensures the fuel lines are filled with LPG in liquid state to maximise the energy available from the fuel.

Photo by Jacks click to enlargen.

===Filling the tank:===
With the connection of the female bowser nozzle screwed securely onto the (male) tank filler fitting , the trigger on the female's nozzle can now be squeezed/pulled up, this will now allows the ball valve/ check vale to open, thus allowing the LPG to start filling the tank, when the tank is nearly full the filling process will start to slow down to a trickle, then when full, ( 80% ) a blow off valve, inside the bowser nozzle will blow off (psssssshtututututu), a small amount of LPG will discharge into the atmosphere, you can see it as the LPG turns to gas once it mixes with the air, you can also hear it and smell it.

VT Commodore with factory fitted LPG. See Oinks post in the text. Click to enlargen. Photo and info by Oinks308.

===Shunt Valve:===
The filling coupling on your vehicle has a ball type valve that seals the LPG off called a shunt valve. The purpose for this is mainly safety. If the shunt hose gets accidentally separated or ruptured from the tank filling connection then only a small amount of LPG will escape.
The shunt valve ball can be activated by pressing it in, LPG will then escape out, so don’t go fiddling with it.
On the outside of the filler connection fitting is a coarse thread, and screwed onto that is a cap. This cap keeps the elements out. It also protects the shut valve along with the coarse thread that the female coupling of the bowser nozzle screws onto.

===Bowser Nozzle:===
When the nozzle is attached and screwed up tight on the coarse thread, it is sealed off by a rubber gasket located in the pump nozzle. As LPG enters the tank in liquid form, the pressure of the LPG opens the shunt valve, and the tank then starts to fill up, care should be taken that the nozzle be screwed on correctly and no leaks whilst filling the tank

 

===Automatic Float Level (AFL):===
Inside the tank is a float arm, this rises in proportion to the level of LPG entering the tank.
There is a sight gauge as a rule on the outside showing the level of fill as well.
When the tank is full of LPG,(80%)then the AFL shuts off the supply of LPG to the tank, so you can’t over fill the tank, thus allowing room for expansion of the LPG inside the tank under all temperature variations, another safety feature ..
When driving and the fuel gauge reach near empty mark, you will start to slow down, as the liquid LPG is just about gone. In fact you can idle for a while just on the vapor fumes alone.

===Pressure Relief Valve (PRV):===
The PRV is fitted into the tank valve area, another safety feature designed to safely discharge the LPG vapor to atmosphere should an overpressure situation be s encountered and so avoid the failure of the tank.
NOTE: The AFL is not seen in the above Tank picture, as it's obscured behind the AFSOD solenoid switch.
The LPG tank brand is “Manchester�?

===Automatic fuel shut-off device:===
Automatic fuel shut-off device (AFSOD) is a safety device which is automatically set to prevent the flow of liquid to the service line and the converter/vaporizer unless the ignition is on, it must be located near the tank and in a protected position.
It’s fitted on the outlet pipe from the tank and activated by a solenoid switch. The function of the AFSOD is to close the system when the engine stops or when running on petrol, and it’s usually connected to the ignition system.

===Converter/Vaporizer:===
LPG goes from the holding tank via a filter to a small round cylinder called a Converter/Vaporizer. Inside this Converter is a water jacket where hot water circulates. It serves as two functions. One, it stops the LPG from freezing up in the converter; secondly, it helps to change the LPG from liquid to gas. There are other ways of heating the converter etc, but I’ll deal with the most common way which is by having two water hoses hooked up to the Converter. One being inlet the other outlet or the return hose.
Markings on the converter body are usually present, so the hose connections can be fitted correctly. As a rule these hoses are teed off from the engine cooling system. Once the LPG leaves the converter it is then in a gaseous form. The changing of the LPG to a gaseous state cause a refrigeration effect, hence the heating chamber on the converter
There are several types of converter/vaporizers on the market. All have their different ways of operating. The two stages is a bit like two stage barrel carby when a certain level is reached then the next level takes over. Well sort of, anyway there are others as well, two stage tandem, three stage, vacuum and so on, but in the main, what we want to do is to make sure that the pressure and air flow mixture is supplied correctly as possible to the engines demands. as well as getting the right volume in accordance with the vacuum signal given from the mixer to the converter ,
Not unlike a carburetor in some ways.

===Mixer:===
The Mixer is a usually a round aluminum ring devise which is connected between the top of your carburetor and the air cleaner. Mixers come in all shapes and sizes, depending on the engine size.
There is a connection fitting protruding from the mixer for a pipe to be connected onto the converter. This pipe, being a low pressure line, usually only requires hose clamps in its fitting. It is best to have this pipe as short as possible, 30cm max, it will also give a better response time when you hit the accelerator, as the signal has been received from the mixer that respond from the converter. I think the length of this pipe is a Law requirement as well, not sure.
Not only is the shape of the mixer important but also the size of the venturi. The smaller the diameter, the higher the vacuum signals to the vaporizer, the more accurate the LPG flow. The disadvantage is that the engine gets less mixture because of the small diameter. This means it looks as if your engine can only drive half throttle. Especially cars with injection or big carburetors as they will have a high power loss. (Up to 20%). So it’s recommended that the ventures must be at least 75% of the superficial measure of the carburetors venturi or butterfly valve if it’s an EFI engine.
It’s very hard to achieve the right combination of air/gas mix as well as swirl, for a good carbonation of the LPG, so one of most important parts in the design of the mixer, is the LPG/air flow exit of the venturi. It must have an 8 degree angle to achieve a constant ratio of LPG with air. Another problem is the pipe line, as it’s far away from the converter and the mixer won’t make the gases swirl, so the gases don’t mix with each other to get a good carbonation.
So as you can see, in order to combine the demands of air/gas and swirl is almost impossible. The main problem is you can get a good mixture at one load yet lean or rich at others. The venturi size is another thing, as the smaller the size the greater the vacuums signal for the converter, on so on.
The pressure drop caused by the venturi restricts the flow of gas through the tube, so it is paramount the Converter/vaporizer be set correctly in order for the correct ratio of fuel/air to occur.
Nevertheless the LPG system is getting better as time goes by, we can now have LPG injection and can remap as you drive, so LPG is the way to go, will definitely save you heaps of $$$


===Adjusting screws:===

===Sensitivity===
On the side of some converters are two adjusting screws, usually close to each other. One is for the Mixture control, the other one is the Sensitivity adjusting screw. This adjusting screw normally has a spring wrapped around it, (a bit like the throttle adjusting screw on your carby) so if your engine is stalling then it needs to come out a smidgen, so turn it out, anti clockwise, say half a turn and see how it goes. If it is still stalling then repeat the procedure.
The sensitivity is the small pressure that is in-between the atmospheric pressure and the large diaphragm inside the converter
When you do move the sensitivity screw, it will alter the effect of the mixture as well, so it really needs Dyno tuning to get it set right.

 

===Mixture===
Don’t move the Mixture jet screw, as you really will need to get this done with a gas analyser. It’s placed up the exhaust pipe to get a correct reading of the mixture. You can’t really do it properly without one, and in saying all that, it will definitely pay you to get a Dyno tune from time to time to get the mixture and idle set correctly. It will save you $$ in the long run as well and your timing etc can be set to suit.
If you’re only going to use LPG, then get the dizzy re-graph and set the static setting accordingly. You can also change the cam as well, in fact there are a number of things that can be done on LPG but it’s the same old story, is it performance you want or economy, and I suppose the governing factor is how many $$$$ do you want to outlay

===Solenoid switches:===
The LPG flows through a number of solenoids valves operated switches, mainly being a safety lock When your ignition is switched on for either Petrol or LPG, you will hear a clicking noise; made by the solenoid switches that operate the fuel supply lines. As one opens up then other one closes, and visa verse, some times these little suckers can play up, so best to keep a spare one handy in the glove box.
To test if working put your finger on top of the solenoid switch, then activate the switch. You should feel a movement in the solenoid switch If you can’t then it either a bad connection or faulty solenoids switch, that’s the best way, as sometimes it’s hard to hear the solenoid clicking. Further more you don’t know which solenoid it is clicking, so hence the reason you need to feel them, you should have about four of them in the system.
More to follow, as time goes by, others are more than welcome to add, or correct as I’m no expert, just giving a rough outline to help those that don’t know about LPG.
More LPG images are in Jacks' shed under [LPG Setup[1]] .

==Some more on LPG:==

===Tips, Does and Don’t:===
Points to take into consideration
Some problems that come up when running LPG do get blamed on LPG, when in fact it’s not
Any problems that exist when running on petrol will still be there when running on LPG.
Make sure that the coolant is the correct mix, (anti freeze) if it’s too weak then the converter may freeze up on you
Don’t run your LPG on empty.

 

===Octane:===

Higher octane requires better spark intensity to burn quicker it also needs more advance in the timing.
So as LPG has a high octane, usually around the 112 mark, so it will produces virtually no ‘Pinging’ like poor-grade unleaded Petrol. (LPG as a liquid also does NOT burn)

Caution: you can still get pinging but its harder to detect on LPG (audible) so never run you engine to long when pinking, as damage to your engine can occur in a very short time

===LPG Saves you money:===
The best part is the running cost, as it should reduce your fuel bill by 30-45 %
If you current petrol bill is say $100 pw, then you switched to LPG, thus saving $30 pw, that’s $15,600 over ten years.
Further more by running on LPG it will extend the life of an engine three fold due to its almost perfect clean burn and virtually zero contamination of your engine's internals
Your oil will be a lot cleaner a well
Now if you have a mortgage, then the $30 pw saved, can go to it, see how much you save off your mortgage, you do the sums it unbelievable

===Ignition:===
Like I said before, an engine that is 'missing' or running inefficiently for whatever reason will do just that on LPG not only that LPG can be more demanding as it’s a higher octane rating than Petrol, so it needs a much bigger spark to get it going
It’s imperative that your entire ignition layout be of good quality, this include the distributor cap, coil, all HT leads, plus the correct Spark Plug and Gap setting etc.
They can appear to be perfectly serviceable, but cause problems when running on LPG. This is because LPG / Air mixture is much harder to ignite than Petrol / Air mixture.
As the voltages generated, in items such as HT components (just before the spark occurs) can be up to twice as high on LPG
Normally the spark voltage for Petrol is around the 10-15 Kv’s, whereas on LPG It can reach 30-35 Kv’s
So as higher spark voltages are much more on LPG , then HT components is at least twice as likely to break down the insulation of any component, causing 'tracking', misfiring etc. which often results in backfiring.
Thus, faults that are NOT evident when running on Petrol can show up on LPG with quite serious effect

===Timing:===
It is also imperative to get your timing correct, LPG needs more Advance, than when running on petrol
Unfortunately when duel fuel is set up on some LPG conversion, the static timing is not quite correct, as Petrol has one setting whilst LPG needs to be a bit more advanced, so they compromise and usually set it somewhere in between
Therefore as it’s not set up correctly for either fuel, this then means you’re getting bad performance as well as bad economy
However there are some manufactures that have duel ignition setup, which can be incorporated into duel fuel system, so it’s recommended to have this type of setup, an extra $280 I think, not sure
Naturally the best thing is to have it tuned only for LPG; still it’s nice to have a choice
I have made my own set up were I can move the Distributor to suite either petrol or LPG it’s a simple DIY job if you a handy man, the out lay is mainly your time

[DIY Jacks Adjustable Distributor [2]]

===Suggestion===
If you have got a points distributor, an electronic one will give you good stronger spark right across the rev range, make sure you get a coil to match as well, don’t use the old coil, it will be the wrong type


===Cold Conditions===
Be sure to keep your coolant topped up to the correct level; otherwise the converter can freeze up on you, also, it’s possible if your coolant mix is very low in anti freeze, driving at night, the ambient temperature outside is very low, including the wind chill, plus refrigeration effect of the converter can and will freeze up on you, don’t forget the converter can be a lot colder inside than outside temp, thus causing weak mixture backfiring or gas leakage when the parts freeze up
If you have duel fuel, run the engine up to temp on Petrol before switching over to LPG, as freezing up cannot occur as the engine coolant will already be hot.
Don't be fooled into thinking that the surrounding air is too warm for freezing to occur, outside temperatures do not have to be down to freezing level for this to happen.
The converter may freeze at temperatures up to + 25 degrees Centigrade, especially if the air is very damp (humidity)
If your in a very cold place, only on LPG, then make sure the anti freeze is right in your system, you can preheat the converter with an electrical heater, have read it been done some place.
So as you can see if you start up from cold on LPG, the Converter needs to be heated up ASAP, so best to have your pluming of the hoses to your converter by the shortest route possible from the heat source of your engine, turning your heaters off will help as well

===Valve Recession===
When leaded fuel was around it secondary function was to cool and slightly lubricate the vale seats.
So If your head has not been modified for LPG, (harden valve seat inserts etc) then I strongly recommended you do get it done
LPG will cause valve recession on unmodified valve seats and will in fact cause it to happen at a faster rate, as the valve and seat temperature are typically higher, than on Petrol;
However there is another way of getting around the problem, if head modification is not an option, you can fit an oil drip feed of Upper Cylinder Oil
This set up is an easy DIY job, the oil is draw into the inlets by a vacuum hose drawing the oil from a container mounted in the engine bay, the oil is sucked into the inlet side so the oil gets to the valve seats were it’s required a well as lubricating the valve guides
The vacuum hose should be mounted below the butterfly of your carburetor, this oil has a very high flash point, and so is suites the requirements needed.
The downside is that this setup is totally reliant on the driver making sure that the container does not run empty.
I have fitted harden valve seats in my 202, but I still use the upper cylinder oil, to me its cheap insurance and peace of mind,
[Flash Lube[3]]

 

===Don’t run on empty===

The LPG tank contains some fuel in liquid state and some fuel in gaseous state.  As the fuel is used, the liquid level drops and the amount of gas in the tank increases.  This phenomenon causes the overall pressure in the tank to remain fairly constant, with the liquid sitting at the bottom and being pressed at a constant pressure by the gas above.  The fuel intake lines are taken from the bottom of the LPG tank, ensuring that the lines are generally filled with liquid fuel. 

However, if the fuel level drops enough, the liquid will drop below the fuel intakes allowing gaseous LPG to enter the lines.  A given volume of gaseous LPG contains far less energy than the same volume of liquid LPG and will cause your engine to run lean, if at all.  If the fuel level drops so far that all the remaining liquid phase transitions to a gas, the pressure will reduce further as the fuel is used reducing the amount of fuel delivered to your converter and ultimately to the engine.

If allowed to get to a critical level, the fuel/ air mixture can become so 'weak' (not enough fuel mixed in the air inducted) that the engine may 'backfire' through the induction system, especially when the throttle is opened wide from a low setting.
If you let your LPG tank run right down to empty your chances of this happening increase a hundredfold
You may normally expect fair warning of low LPG tank contents from your vehicle as the engine may well become 'sluggish', especially during acceleration (much the same as running out of Petrol). If this happens, don't wait for it to stop altogether. Switch over to Petrol right away
Some fuel guages may not be accurate, so if you take note of what you get from a tank full of LPG then after a while you will know when refueling is due.

 

 

===Air Filter===
It’s important that you air cleaner be kept clean as it will alter the mix of gas that the converter sends out to the mixer, so there by giving you false economy, as well as the performance dropping off, backfiring may occur as well
When on LPG, the mixture is critical to the performance as well as the economy, you can notice this more so by this little experiment
When your idling on Petrol remove your air cleaner, note the difference in the running of the engine, then do the same when on LPG you will notice a marked difference as LPG is very touchy on the air flow as this has made the overall mixture too lean, now if you restrict the air flow, then its to rich, so hence a poor idle performance as mixture is in relation to fuel and air
So It's important that your air cleaner be kept clean, as it will alter the gas flow from the converter, so there by giving false economy/performance as the mixture will be out of whack and backfiring may occur.


==Did You Know:==
LPG in a gaseous state will mix with air much more readily than Petrol.
LPG when exposed to air will vaporize, it will do this right down to minus 42 degrees C, which ensures that it will vapourise in all but the coldest climates and conditions
Liquid state propane is not heavy. Its S.G. (0.5) is lower than that of Petrol (0.72).
LPG has one unique and very special property. If mildly compressed it easily changes to a liquid state.
Store LPG in a pressurised tank and it will remain liquid, occupying only a small space.
Release some of the liquid and it will immediately revert to its gaseous state, expanding as it does so.
It needs very little encouragement to vapourise and lends itself more readily to mixing with air (to get the Oxygen required for a combustible mixture).
Vapourised LPG, however, is 'heavy', i.e. heavier than the surrounding air if allowed to escape.
Liquid Propane expands to 250 times its liquid volume when reverting to gas.
The reverse applies, as gaseous LPG will 'shrink' by 250 times when compressed and liquification takes place.
LPG is 30% more in a gaseous state as to Petrol in a liquid state
LPG is the pungent smell, designed to warn us of its presence. In its pure state the gas is colourless and odourless
No Octane enhancing additives are required to be added to LPG, unlike Petrol
Exhaust systems has been proven to be extended by three times when LPG is used as a fuel.
LPG needs no fuel pump to get it out of the tank and up to the engine, as the large pressure differential between the tank's interior and the atmosphere takes care of that for free
Running on LPG will ' warm up ' more quickly than it would on petrol.
Petrol consumption is extremely high when the engine is cold as a choke or excess fuel device (both giving a very rich mixture) must be used.
LPG scores over petrol again, as this (choke)is not necessary.
LPG does not need an artificially rich mixture and the engine warms (to its normal operating temperature, where it is most efficient) more quickly as a result.

Read this some place
LPG backfire had shattered the plastic PCV valve.
The ball bearing inside the valve had found its way between the timing chain and its sprocket...
So... rebuild or replace - either way, she's in the shop for a while and it aint gonna be cheap.
The worst bit? Metal PCV valves are available for $10

Photo by Jacks click to enlarge Converter


==Converter:==

===Cooling System===
Photo by Jacks click to enlarge Converter Cooling Chamber

The picture on the right shows the Convectors cooling chamber, you can see it looks a little rusty in appearance, I‘d say that the previous owner didn't have the right antifreeze/coolant mix etc.
The small 'S" shape pipe in the left section, is the LPG line itself so you can see the cooling water that surrounds the LPG pipe helps to warm up the LPG to it's gaseous state.

===Part Names===
Photo by Jacks click to enlarge Converter OMVL R90/E

Picture on the right is a OMVL R90/E Converter.
More details on other model LPG Converters in my sheds
Click link below
LPG Converters

If you want to add more to this, please do, if there’s a mistake please correct
Cheers, Jacks

==Troubleshooting Lean Running:==
Submitted by v8slrtorana on Sun, 18/02/2007 - 07:28. 308 | Engine | LH | Silly
I've been having a little trouble with my motor ruing lean on LPG. It would get to about 4500 - 5000 rpm and start breaking down.
So, I asked a few questions here and there and was told it might be leaning out. So i fitted a autometer air fuel ratio guage, and yep, that was my problem.
So did some homework, and found out some things I didn't want to know. To get the LPG to the engine, I had to fit a high flow gas tank, with 2 outlets, run 2 supply lines into 2 mixers to feed my carbies. This is starting to look expensive, due to the fact, i had 2 x 225 impco carbies that would be at their upper limit if the above mods were to be carried out.
The LPG answer was to buy new tank, 2 new converters and 2 new impco 425 carbys.
Then, hang on, who in Darwin has reliable LPG knowledge??, err, yeah well.
So, i buy myself a 750 mighty demon, hhhhmmmm, what a sexy piece. Then a procrap aka procomp black (holley black copy) fuel pump, a alloy 57 litre foam filled cell and plumb it up.
Result, 7500 rpm, yeah Ha!!!, time to set the rev limiter!!
Oh, and the air fuel gauge, happy from idle to 7000rpm.
Lesson for my story, don't get carried away with a engine build up, it might cost you another 2 grand trying to get the fuel into to keep it happy.
What was going to be a 308 with small solid cam ended up being a 355 harrop stroker with crane 288, weiand inlet manifold, 2.02" and 1.6 valves and appropriate porting 3800 stall, the list goes on.

End of v8slrtorana's submission

 

Yes T those are the Pics;
P1010015-1024x
P1010016-1024x
P1010017-1024x
P1010018-1024x

The story was; an elderly Gentleman was looking at retiring and did not wish to buy another low mileage ex-Police Car so went to the local Holden Dealer in Melbourne to Order a brand new VT Commodore Sedan, it had to be Yellow for the Cab Company he drove for (QLD'r so no knowledge of this?) so he ordered a tacky Yellow Sedan, but it HAD to be straight LPG, by the plaque fitted, it was fitted in QLD in 1997, so maybe it was a Brisbane built and supplied VT Commodore? :{/

The only thing he never told the mate who bought it from him was the bad habit of blowing the Air Boxes, one or two a month normally, sometimes more, and when they go he says they shatter into hundred of tiny pieces, so it really does a job on them...

It drove from the lot as a dedicated LPG ONLY VT Commodore, the complete Fuel Tank and lines etc were all removed prior to Delivery, FJWB tells me Holden never offered straight LPG as an Option, but we all know some of the weird offerings from the Big 3 over the years if you knew which string to pull...

I have looked at quiet a few LPG Dual Fuel setups to fit to the VS Ecotec V6 Motor I am fitting to my '47 Singer Hotrod project and I have never seen a setup that looks like this one...

As I said, I hope it helps someone down the track... ;{D

Cheers Pig (OINKS308)

Carbon buildup on 202 Inlet Valve caused by LPG use. Photo by SamWB. Info by Ben Simpson. Click to Enlargen.

===Checks:===

Do the easy checks first, check that the wiring to the gas safety solenoid is nice and solid, a loose connection there might drop the signal from the module and cause the fuel to be cut off. Also check that the engine and ignition earth feeds are nice and tight with good metal to metal contact surfaces.

A restricted fuel feed can also cause these types of symptoms. If you put your foot down it leans out too much and stalls or bogs down. Common symptom on petrol engines when the fuel pump is failing I've had that happen to me numerous times. On gas it could be the water flow in the converter, check that the converter has good flow of water going through it, one hose should be slightly cooler than the other is a simple way to test it. It should also be warm to touch the body when the car is warmed up and at idle, if it feels cold that is an indication that the water flow is probably restricted and it will cause fuel feed issues.

My son's cars LPG had the water plumbing wrong when he got it fitted, whenever he turned the heater on the converter played up and caused the car to run like crap and often would stall on take off after a couple of minutes. I changed the way a "T" piece connector in the water hoses was configured and fixed it. Water likes to go in straight lines. Its the sort of "bug" that could do your head in as its not all that obvious.

Other than that is the new coil the right type? A points coil will cook on a HEI feed. When it begins to die it will randomly lose spark or start to produce a weaker spark which dies under a sudden increase in fuel or load. (Similar to a failing module)

Anthony - Lettuce Alone SS

End of submission Anthony - Lettuce Alone SS

===Links:===

Cutting Out Thread

LPG Carbon Inlet Valve Thread

Oink's Shed

===Terms:===

Terms
Back to the Fuel System Section