[Che]

I'm a first time poster here after having no luck in another forum... I guess US Suzuki forums deal mainly with Samurai's - the Ausiie Sierra is a little different (1990 Hardtop, BTW).

Anyway...

I'm changing to LPG so I want to rid all the seemingly unnecessary components of the stock carby and all related matter. Things like the fuel pump, fuel lines and petrol tank I already know about, but I plan for a good tidy-up under the hood and want to get rid of all I can.

Seeing I have to get the carby rebuilt and the fuel tank replaced anyway, I might as well take advantage of the $1750 rebate going and change to LPG - it'll only cost me a few more lobsters than a straight up fix of my current woes. I don't need too much cargo space, so I'm hooking up a reasonable tank that'll hopefully give me a 600km+ range. Sounds big but I still have plenty of boot left to play with after seeing the tank installed earlier today.

I took some pics, hopefully you can identify their purpose for me and if they are necessary to keep my beastie running once my conversion is complete.



I'm unsure if this thing is a second fuel-line filter or a vacuum canister of sorts... it runs to the carby though, but seems to be seperate from the main fuel line I identified:




This vacuum thing is attached to the intake manifold, and runs to the sensor (red circle) in the next pic:




The green circle here seems to be the temperature sensor and i'll still be needing that obviously, but the red circle is another sensor - I got no idea what purpose it serves:




Any help much appreciated

[wyt91t]

LAST ONE I THINK IS THE VACUM SENSOR (red circle)

[royce]

first one, Charcoal canister, holds onto the fuel vapour from teh tank and burns it off, no fuel tank no need for it

second one is EGR, allows an amount of exhaust gas back into teh intake to reduce emissions, not sure on this, maybe but would pay to check and its probably clogged up anyway

3rd one is the idle up solenoid, when all the bits work it ups the idle speed when you turn the headlights or heater fan on, once again probably doesnt work anyway

Straight gas has special rules for emissions stuff so you can probably lose the cat convertor as well, I wouldnt bother with trying to keep the carby, get a proper gas carb for it so you dont lose any power

[steak_knife]

As royce said, but I'm 99% sure the egr has to stay.

[want33s]

EGR not necessary on straight gas.

[steak_knife]

want33s wrote:

EGR not necessary on straight gas.

& there is that 1%..

[shep]

i don't have any of those bits on my sierra and it didn't run any differently after i took them off.

[steak_knife]

shep wrote:

i don't have any of those bits on my sierra and it didn't run any differently after i took them off.

But you told us rear shock's didn't make any difference either..

[shep]

steknig wrote:

shep wrote:

i don't have any of those bits on my sierra and it didn't run any differently after i took them off.

But you told us rear shock's didn't make any difference either..

haha it is a bit more bouncey

[steak_knife]

shep wrote:

steknig wrote:

shep wrote:

i don't have any of those bits on my sierra and it didn't run any differently after i took them off.

But you told us rear shock's didn't make any difference either..

haha it is a bit more bouncey

You don't have as many rule enforcer's as we do.

So your car is Tigger, love's to bounce!!

[shep]

i gave a copper a lift the other day and all he said was, why are there big
hole in the floor? i just told him they are there as the roof leaks.

[Che]

I'm using a stripped Aisin carby as a throttle body only (may need a basic rebuild due to a vacuum breach somewhere), and the gas mixer will sit on top. I could go an aftermarket throttle body but it all costs money - stock will do the job for now.

I've looked at some performance LPG mixer/carbs, but a gas mixer with too high a flow for the engine = idle problems + gas thristy... too small a mixer = poor top end RPM + lower highway speeds. You gotta install to suit your needs. The LPG installer (Metro Gas, Bris) has done a few Sierras, and he knows my desired outcomes, so i'll trust him to get it right.


What part of the carb requires connection to the electrical loom, or can I ditch this too? Not sure if it's controlling the choke, certain sensors, or maybe even the secondary throttle plate...


I just took another photo to help, if anyone can point out the parts circled/numbered i'd be much obliged - certainly the most complicated carby setup i've ever encountered... time to simplify if possible




Great forum BTW, good to see there's a heap of Zooker's in Australia.

[want33s]

1, Plug to fuel cut solenoid and pollution switch. Not needed on gas.
2, Pollution switch.. Not needed on gas.
3, I think it's something to do with AirCon idle up.
4, Not sure.. Been a while since I had a carby on mine.
5, Pollution control temp switch.. Not needed on gas.

[ZookiMonsta]

I think 4 has something to do with the vaccume advance on the dizzy.

[Che]

Where's the water choke adjustments on an Aisin carb? I'm guessing it's a water choke anyway, due to the amount of shared hosing between the intake manifold and carb.

Do I really need a choke (1) when running straight LPG (2) living in SE QLD?



So the electrical loom (#1 in the last pic) on the carb deals with the pollution controls... Can I just turf this, or will I still need elements of the loom to service other things?

[shep]

3 is the idle up for aircon

[want33s]

che_guitarra wrote:

So the electrical loom (#1 in the last pic) on the carb deals with the pollution controls... Can I just turf this, or will I still need elements of the loom to service other things?

want33s wrote:

1, Plug to fuel cut solenoid and pollution switch. Not needed on gas.

I don't think a choke is needed but a call to a gasfitter would easily clarify that.
If there was a choke it would be in the mixer not the carby anyway as the carby is now only a butterfly/throttle body.

[11_evl]

I'm running my LPG thru an efi throttle body and the only thing I have hooked up Is the idle solenoid to a switch and coil. Everything else is disconnected. I'm using the 16v baleno manifold.

[steak_knife]

11_evl wrote:

I'm running my LPG thru an efi throttle body and the only thing I have hooked up Is the idle solenoid to a switch and coil. Everything else is disconnected. I'm using the 16v baleno manifold.

Why LPG??

What mad you change over??

[Che]

want33s wrote:

If there was a choke it would be in the mixer not the carby anyway as the carby is now only a butterfly/throttle body.

Too true Well- I think i'm gonna have a nice tidy engine bay by next weekend. Goodbye overbearing carb controls, hello simplicity, hello reliability.


But before I tear everything off - how is the carb's second throttle plate controlled?



Also, how to plug the mechanical fuel pump hole if I take it out, also the various holes left in the intake manifold? Just shape fitting pieces ( or gaskets or plugs) and bolt it on, or more to it?

I can't say I want any random vacuum hose dead-ends (sealed with tight fitting screws) dangling around the engine bay either... a simple and uncluttered engine bay lends to easy maintanence.

[11_evl]

steknig wrote:

11_evl wrote:

I'm running my LPG thru an efi throttle body and the only thing I have hooked up Is the idle solenoid to a switch and coil. Everything else is disconnected. I'm using the 16v baleno manifold.

Why LPG??

What mad you change over??

carbs suck.
swapped them, re kitted them.
hills and angles arnt carb friendly, my car will now run on its side if it had to.
to go EFI i had to get a full engine loom, wire up, tidy wires.
LPG i have a tank in the back. ican now move my diff back, i dont have a stupid tank to get hung up on.
and it makes my car a bit more doey so i wont brake as much stuff

as for your fuel pump. just use gasket and cut out a steel or alloy blanking plate, i think with most of the vac lines you can buy blanking plugs to go over barbs,
the secondaries are normally vac operated. i guess you could take your carb to a wreckers and match up one that has mecanical sec and lots less emissions???

[Che]

11_evi, what's your LPG setup? Do you know what kind of mixer and regulator you're using?... just curious

How far are you getting on a tank of LPG, and how big is your tank?

[Che]

In this pic i'm trying to point out the thing bolted onto the manifold under the hose, BTW

[royce]

Thats the egr valve already been said you need it
The vacuum solenoid behind the thermostat housing controls it so you need that too
Posting on my phone so long posts suck but a simple mixer like you propose is going to leave you disapointed with the power loss
I may also say if a few vacuum lines worries you so much (and it is all reliable) then you might need to study gas some more

[want33s]

EGR is NOT needed IF running dedicated LPG.

[Che]

royce wrote:

Thats the egr valve already been said you need it
The vacuum solenoid behind the thermostat housing controls it so you need that too

t's also been pointed out I don't need it, too! (edit - you beat me to it want33s!)


A moderate power loss won't bother me if i'm getting good economy, i'm just running a standard zook with K&N and soon to install extractors/2in exhaust (I won't need a cat conv either). That's pokey enough for a little car - if I need more 'go' I should've bought a more powerful car to begin with.


Like I said previously, I've told the LPG installer what my expectations are in terms of performance outcomes, and he's certain he'll deliver - he expects i could get around 90hp with my basic mods installed. I've gone to him after seeing another Sierra w/ LPG he'd converted, so no reason to doubt his ability. I've also checked out the IMPCO components he plans to install (their specs, flow rates, pros/cons, competitor options, etc), and from all the information I've gathered, the guy's right on the money. I could go a mixer with higher gas flow, but with that comes higher running costs, and the hp performance gains will mainly be felt in an RPM range I rarely use.

[royce]

90hp! Are you turboing it?

[11_evl]

im running a landi converter with a venturii on the throttle body




plus if your LPG guy knows anything about turbo and gas, pm me his details, id like to have a chat..

[Che]

royce wrote:

90hp! Are you turboing it?

No, but a mixer with a flow rating of 240hp/350L/S combined with a 420+ spec regulator is forcing things in at a pretty high rate - push the boundary any more and the idle will start to turn ugly, and you can throw any sort of economy out the window. Check it out at gotpropane.com - we're basically using the same components as in the Samurai kit these guys offer. Only instead of using an OHG throttle-body and manifold adaptor, I'm using a stripped down 2bbl Aisin and IMPCO mixer equivilient. 90hp might be a little rich, but if i'm not getting at least 80hp, something is going wrong.


Yanks seem have been pushing 100hp in their natrually aspirated 1.3 Samurais using straight propane for quite a while (given, Autogas is the best we get)... I can't see why it's possible for them to get good hp figures and not us??

[Che]

Well, LPG is all installed now, and can I say the bump up in torque is fantastic, so too the general power increase in the sub 4000 RPM range - no chance to wind it out any further as yet - that's my job for today!

After getting installed I had to go with a lesser mixer than I intended, as idle was a little ugly, but i'm very impressed with LPG so far - now I just gotta test the range of the tank.



Anyways - where's the fuel cut solenoid? Is it on the back-side of the carby or bolted to the firewall somewhere. Trying to follow the electrical path, but I lose it when it goes under a bunch of vacuum lines on the manifold.