EJ22 on LPG wiring?

tambox · Post by **tambox** » Tue Jan 08, 2013 4:07 pm

I am finishing the wiring on my EJ22 L series, it also runs on LPG.
I am looking for advice on a simple way to turn the fuel/injectors off, without getting fault codes from the (early gen1) computer.
At the moment it just turns the pump off and removes the injector power feed, but the computer is unhappy

I have several ideas, they are not as simple, but not sure which is the best way to go.
Some advice would be appreciated.

AlpineRaven · Post by **AlpineRaven** » Tue Jan 08, 2013 8:33 pm

Gotta trick the ECM from throwing the codes.. I was going to say speak to LPG specialist.
Cheers
AP

tambox · Post by **tambox** » Tue Jan 08, 2013 8:44 pm

All the ones I spoke to did not or had not done a Subaru as you cannot buy a kit for it.

steptoe · Post by **steptoe** » Wed Jan 09, 2013 6:12 am

an emulator is what you need, and from memory they are universal sort of thing just to keep CEL happy, they were only needed in some conversions - Mitsubishis ??

Get onto Apollo in Melbourne ,maybe http://www.peelinstruments.com.au in Adelaide ....

5 am !! Hot night or can't sleep due to this problem !!

http://www.peelinstruments.com.au/page17.html should be a good start to the concept etc

tambox · Post by **tambox** » Wed Jan 09, 2013 11:11 am

An emulator of some sort is one of my options.

As the injectors are fed 12v and switched by earth from the ECU, the ECU is looking for 12v when the injectors are not being operated.
If I connect the injectors when its on gas, the ECU is happy, but Im not, as the injectors are running dry and hot.

The way I did it on both my EFI ea82 l series on LPG, was to set up a relay to disconnect the injectors and connect some resistors (emulators), tied to 12v.

I was hoping to get out of more relays.

If I can get a swichable emulator, for a reasonable cost, I would prefer that.
But apparently you have to get one to match your ECU.

I have also been told by people that work on Suabru's that all the EJ22s they have ever seen on LPG, always have the check engine light on. ??

Thanks Steptoe, tried to call them, no answer, probably still on leave.

steptoe · Post by **steptoe** » Wed Jan 09, 2013 11:45 am

Sounds like you know what you are doing, which is good when it comes the clear liquid under pressure

You must know about the 87, 87a relays then, that are used in the either petrol or gas situation where 87 drives say petrol, 87a gets nothing until you switch relay contacts by your one switch, then 87a gets it and 87 gets nothing - could use same relay to power your resistors, same as other side would kill pump and injectors ?

tambox · Post by **tambox** » Wed Jan 09, 2013 12:05 pm

I just got back from Jaycar with a 4pole DT relay and some resistors.
I will power that from the input to the pump cut off relay, so when the pump is off, the injectors are off and the resistors are in.
My gas/petrol control relays are wired through the gauge, centre off type switch, so I will only get either.
The only unknown bit is if the CPU monitors the operate current for the injectors, then I will have to play with the resitor values.

Yep had most of my stuff on gas since before the end of last century.
Love the stuff, specially when you get into pre-heating the intake on LPG and run lots of EGR. Its amazing what you can get out of LPG.

Time to solder.

tambox · Post by **tambox** » Wed Jan 09, 2013 2:25 pm

The relay and resistors has made the CPU (and me

) happy.
No engine check light on gas, also set it up for petrol on crank, to help the lpg start.

Now to properly sort out the A/C wiring.

Thanks for the suggestions.

steptoe · Post by **steptoe** » Wed Jan 09, 2013 9:54 pm

Good stuff, but do tell at least the relay and resistor part no's and how you wired them up ?

And preheat the intake ? How much more than std EGR do you run ? My ECU is supposed to only operate at op temp and between off idle and 45 kph according to manuals, but operates at any temp and any speed above idle - with the right vacuum.

Ever try LPG boosted ? That is fun

tambox · Post by **tambox** » Thu Jan 10, 2013 10:43 am

I just used the Jaycar 4PDT (SY4009) relay and 100 ohm, 1watt resistors.
Cut the 4 injector wires at the CPU, connect to the relay, (1 injector per pole) so that when the relay is operated it connects the injectors as normal.
Solder 4x 100 ohm resistors to the spare relay tabs, then common the other end of the 4 resistors and connect to 12v (mine is connected to 12v switched on with gas).
This is an easy way to trick the CPU.

LPG has a lot of potential people generally do not use/understand.
If you can find anything about LPG, cooling systems and water pumps written by John Bennet, it will take you down a different path about what to do to get the most out of these.

Basically, the most efficient car cooling system has the thermostat located in the lower radiator hose, with big continuos coolant passages allowing most of the coolant to circulate the motor. There is then a bleed to the radiator to allow the temperature to be controlled. This gives a much more constant temperature to the motor.
But this only works properly with a correct water pump with no cavitation. These are hand made from OEM pumps, its interesting, Ive done a few.
You need to really understand how this works before you play or say its c--p.

LPG is harder to light than petrol and it burns more slowly.
If you preheat the gas to a certain temperature (cant remember, but have notes somewhere) before it is ignited, it burns more quickly and is easier to ignight.
As gas burns more slowly, people put more in to get the right amount to burn to get power, run it richer than is efficient to achieve this.
I have seen a Bennet modified holden 6 running normal mixtures on LPG, it shoots flames out the exhaust as the gas is still burning, hence people cook their exhaust valves.
With big EGR, the motor actually re-burns the unburnt gases and with run for a moment on EGR only.
Preheated LPG, no flames, better economy, amazing tourque increase.

Its simple to do, but you have to get it right.
I have done it on a 308 holden I used to own, fuel economy incresed by over 50%, tourque increased by 18%.
I could have got it even better, the Bennet figure is 28mpg on an auto 308, I got to 24mpg.

Adding turbo to all of this makes it so much better.

steptoe · Post by **steptoe** » Thu Jan 10, 2013 2:48 pm

thanks for getting some details out, I'll have to look into it and ask my guru if he is still about. Been into LP since 1990, learnt a lot more when I tried to gas my EA82T. I run 0.06mm plug gaps to cater for harder to ignite, slower to burn thing.
Curious to know what make of LP stuff you used on the 308 and the Sube for that matter

tambox · Post by **tambox** » Thu Jan 10, 2013 3:06 pm

Impco rules
Impco is simple, capable, reliable and adjustable.
I currently have L/EJ22, L/EA82EFI and L/EA82 carbie on impco gas set ups.

Out of my many years on gas and 1,000,000+ km with different cars, never burnt any valves. Do it properly and its good. I have a TAFE LPG intaller licence from the old days and used to play a lot on dyno's

John Bennet has written articles in many of the hot rod mags in the 80's/90's. I have some somewhere.
He may be hard to find now, but has gone into setting up diesels to run LPG only.
He has done a few semi's and was working on doing the english taxi's just before the 09 financial meltdown.

Brumby Kid · Post by **Brumby Kid** » Thu Jan 10, 2013 3:27 pm

Talk to Sean at S&J Automotive.
He is in Edwardstown Adelaide.
He is the Subaru performance specialist and go to man when Subaru have a problem.
I'm sure he has done an LPG conversion before, if not he knows these motors better than ANYONE else (including Subaru mechanics) so I'm sure he could at least give you some ideas.

Cheers Cam

steptoe · Post by **steptoe** » Thu Jan 10, 2013 9:34 pm

Well threee on IMPCO LPG here too. Enough to get our own forum going nearly

I can represent the ones you can't with EA81 twin carb, EA81 with Lancer efi throttle body and EA82T drawthrough - 'scuse us, won't you all

Brumby Kid · Post by **Brumby Kid** » Thu Jan 10, 2013 9:49 pm

Johnno are you trying to create your own little club again?
Johnno's LPG Subaru club. Invite only, very prestigious. (Ie. you must at least be wearing thongs and a wifebeater (singlet).
Hahaha
On a serious note, apart from the fact I don't want to lose tray space, I have thought about gas. Since my rebuild I have done 180km. And put in 20L at the start for tuning etc. taking into account carby needs a tune, my driving etc. refilled at 180km and worked out I had used about 15L for 180km.
I then thought of the range if I was on gas. And the cost.
But I'm happy with petrol.

YouTube · Post by **El_Freddo** » Fri Jan 11, 2013 11:03 pm

I remember back in the day you used to be able to do it yourself and it was all good from what I understand...

Cheers

Bennie

steptoe · Post by **steptoe** » Sat Jan 12, 2013 6:23 am

all good ?!! You have got to be KIDDING !! A little north of the border and we see some absolute balls up installs of what must have been DIYVIC jobbies = spring shackles bolts rubbing on tanks at certain points, recycled hoses at least 20 years old. And you'd like to think vics get an annual LPG inspection now - have no idea. We had a ZJ Fairlane come in one day complaining he could smell gas all the way from Melbourne - so took him 600km to do anything about it. On start up with the bonnet raised, my fight , flight system was challenged severely - do I run now? Globs of liquid coming from the safety lock-off/filter and disappearing down below in the coil and leads area. Up the back the brass fittings into the tank had turned black - sign of a long term leak or two.

Also seen non Vic job where someone in the mechanical game trained OS tried white plumbers tape on a fitting not supposed to use any sealant - all in an attempt to fix a leak that was actually a cracked copper line - that was a taxi !

tambox · Post by **tambox** » Sat Jan 12, 2013 11:16 am

The funniest/stupidist/dangerous one I ever saw was a bloke brought an old Fairlane in that he had swapped the gas bits from another old Fairlane, but he had put new pipe on it.
When we looked at it, its was neatly done, but we told him he did not need to put hose clamps on the ends of the hose that covered the copper pipe. He didn't understand and said the gas will leak out.
Turns out he used short pieces of copper for the connections, then just the hose under the car!!!!!

steptoe · Post by **steptoe** » Sat Jan 12, 2013 7:14 pm

.ark ! Must have got a high rated sleeve for that job !! That is almost as bad as the guy who tied in another tank with Telecom rope in the back of his ute just to use it up ! Or the 9kg BBQ bottle turned upside down jammed behind the Festys LHF seat and gas line running along the floor to the engine bay !