Register a SA Forums Account here!
JOINING THE SA FORUMS WILL REMOVE THIS BIG AD, THE ANNOYING UNDERLINED ADS, AND STUPID INTERSTITIAL ADS!!!

You can: log in, read the tech support FAQ, or request your lost password. This dumb message (and those ads) will appear on every screen until you register! Get rid of this crap by registering your own SA Forums Account and joining roughly 150,000 Goons, for the one-time price of $9.95! We charge money because it costs us money per month for bills, and since we don't believe in showing ads to our users, we try to make the money back through forum registrations.
 
  • Locked thread
Applebees Appetizer
Jan 23, 2006

Seat Safety Switch posted:

Yeah, I think I'm the only guy lovingly restoring and modifying a stock '92 Civic tape deck; there's no way the core audience is going to put in more effort than a recap job for a Soarer.

Got any tips on how to unfuck my Protege's tape deck? I think the head must be hella dirty because the radio works but I get almost no sound out of a cassette.

Adbot
ADBOT LOVES YOU

Seat Safety Switch
May 27, 2008

MY RELIGION IS THE SMALL BLOCK V8 AND COMMANDMENTS ONE THROUGH TEN ARE NEVER LIFT.

Pillbug

leica posted:

Got any tips on how to unfuck my Protege's tape deck? I think the head must be hella dirty because the radio works but I get almost no sound out of a cassette.

I'd clean whatever you can first. Note: My plan is to eventually remove the tape playing part of the deck and putting a Chinese Bluetooth audio chip in there.

Applebees Appetizer
Jan 23, 2006

So basically just use some alcohol and a Q tip a scrub the head? Cuz all i need it for is my aux/tape adapter and my one Duran Duran Rio cassette :v:

Seat Safety Switch
May 27, 2008

MY RELIGION IS THE SMALL BLOCK V8 AND COMMANDMENTS ONE THROUGH TEN ARE NEVER LIFT.

Pillbug
Scrub the head and all the rollers. Not sure why that would make it quiet but it probably can't hurt.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
gently caress, I need to post more updates about this car. I've still not caught up to the present day.

So...I tidied up the wiring inside the door that was head together with masking tape, and replaced the weather seal inside.





I reinforced the door cards with fiberglass, just as on the other car (this is a good thing to do).







I replaced the broken tab on the window controls (a common failure). A junkyard gave me a free donor as it was cracked elsewhere. Some solvent cement and fiberglass to reinforce and it's stronger than ever.






I pulled the speed sensor (the car has two, this one is for the dash, and is a backup sensor for the ECU). The shaft seal had failed, and the sensor was full of ATF. Shouldn't make a difference as it's sealed with epoxy, yet a new (good) sensor fixed it.




A larger job was the suspension fluid leak. It was leaking from the valve body - an aluminum block with 70+ dripped and capped holes, carrying suspension fluid at pressures between 1720 and 2100psi. These do not commonly leak, but when they do, it can be a pain to repair. These things are hidden in the front left wheel well, under the bumper, where a washer bottle would often go.



I began by measuring fluid pressures at various points. This doesn't really help find the leak, but will tell me if the unit is healthy and worth servicing. This unit looks fine.





I found the leak to be coming from one of the pressure holding valves. These valves close when the car is stopped to prevent it from sinking to the bump stops when there is not a constant supply of fluid. They are held open in normal operation by fluid pressure which is switched by a solenoid valve, and are essentially an on/off switch for the suspension system. There are 4 of these (one for each cylinder), an they are situated on the side of the unit.

Fortunately for me, the leaking one is on the side that I can access, as removing the unit is a messy, expensive ($110/gal) and time consuming process. Unfortunately, there is a front bumper in the way:



The valve is held in with a 19mm allen nut (it that's what it's called? 19mm hex on the inside, required a trip to the store to buy a set of these in 1/2" drive)





The valve removed from its housing. A large spring is left behind. The section on the right (3rd o-ring) is the moving portion of the valve. You can see the damaged o-ring on the left - this seals the unit from the outside.



Fortunately I have another complete valve body to pull an o-ring from, most o-rings in this system are random sizes, and I don't bother to keep them all in stock.







Once this thing is reassembled, a quick test to verify that my 2-hour o-ring replacement has been successful. While the bumper is off, this is a good time to check the filters and magnets in the tank for cleanliness. First, a pressure test on the pump to ensure the system is running at the correct pressure:




Then 30 minutes of fighting difficult-to-access bolts and hose clamps to access the filters.




Everything was surprisingly clean, so $60 of fluid later, the whole thing was back together and running.



While the bumper was off, I cleaned the inside. Water and dirt collects in the front splitter and it's nasty as poo poo when you disturb it while under the car and it all rains down onto you. I drill a few 1" sized holes in the bottom of the splitter to let this stuff drain out.



One final job was to repair the idler pulley for the suspension pump, as it was starting to make noise.




Done!

I also tackled the broken overdrive switch. This is held in place with a "[" shaped clip, which is conveniently the same size as a regular staple, only with shorter legs. A few seconds with a staple and some wire cutters produced a replacement. Done!

I didn't take and pictures of the brake work - I replaced the old brake lines with braided hoses for a Mk4 Supra (exact same part for a Soarer, thanks Toyota!) as one was leaking, and purchased a caliper rebuild kit for the front left caliper. One piston was stuck in there good, and required some significant force to remove. The pads on the car looked new all-round, but the pads on this wheel were already over half-way gone. Once rebuilt, the caliper actually works as intended, rather than having one piston always-half-on, and the other working.

Still to do:
Brake fluid leak
Broken overdrive switch
Boot lid all lovely, hole in rear bumper
CD player doesn't work
Headlights are full of water
Suspension system is leaking
Active suspension feels very hard, as if the sealed nitrogen accumulators have leaked.
Front left brake caliper is sticking

Jomo
Jul 11, 2009
Amazing work as usual. I always love reading you and the spyder's (rx7) threads as you both make it seem incredibly easy to maintain these cars full of 90's technological extravagance. In regards to converting the stock display, I always thought I'd be cool, but didn't think i'd be possible till I saw it done on Mighty Car Mods with the stock Subaru climate control module. Would of loved something like that on my Legacy. https://www.youtube.com/watch?v=JaI9O5yeuWc

Also, besides the screen module, what are the other parts that are now near impossible to find in good condition?

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
The work they did was pretty cool. It looks as though they did a complete replacement including controllers for the fan and vent motors, along with their own display. They only seemed to re-use the front panel.

It would be a lot harder for me as to retain the touch functionality (actually a matrix of LEDs and photodiodes) system does not exist in any modern devices - trying to convert the output from that panel would be very difficult. A conventional touch monitor would not work as the plastic front 'glass' on the EMV units would get in the way. There is very little clearance around this to mount a monitor flush to the front panel. The actual LCD sits about 5mm behind the plastic. The only solution would be a non-touch LCD with an external touch panel.

Regardless, I love the quirky old late-80's LCD, even if it is not as functional as a modern system, it is certainly more impressive. I run a dateless license plate on my car, and so far no passenger has even come close to guessing the cars age after seeing the tech inside.

As for irreplaceable parts, the entire suspension (pump, struts, valve body, computer, G sensors, gyroscope (actually a vibrating pendulum), front and rear lower control arms) and steering (front steering rack, front slave rack, cable system, rear steering rack, rear hubs, computer, yaw rate sensor, pump, steering column with integrated steering angle sensor) system is unique to the 872 UZZ32s.

As is the alternator, AC compressor, timing cover, oil filter mount on the engine. The longblock is the same as other 1UZFE motors, with one less stud near the oil filter. Replacement engines can be fitted provided that this stud is removed, although the complete front end will need to be swapped over. The ECU is unique to the UZZ32 as it communicates to other systems, but you can mount a UZZ30 or 31 motor to a '32 ECU and vise versa, depending on the chassis. LS400 motors would need a Soarer loom, as the wiring is different at the ECU end (4 plugs on the LS400 instead of 3 on the UZZ3x). Soarers do not have EGR, so the upper intake manifold would need to be retained (trivial) if an LS400 motor is used to replace a broken UZZ32 motor (rare, 1UZs are pretty unkillable).

The display binnacle, rear subframe, washer bottle, PS fluid reservoir are unique to the UZZ32.

The EMV, sonic mirrors, reversing camera, hydroboost ABS brakes are all options on the UZZ31, but standard on the UZZ32. This makes them easier to find.

charliemonster42
Sep 14, 2005

ShittyPostmakerPro posted:

The work they did was pretty cool. It looks as though they did a complete replacement including controllers for the fan and vent motors, along with their own display. They only seemed to re-use the front panel.

It would be a lot harder for me as to retain the touch functionality (actually a matrix of LEDs and photodiodes) system does not exist in any modern devices - trying to convert the output from that panel would be very difficult. A conventional touch monitor would not work as the plastic front 'glass' on the EMV units would get in the way. There is very little clearance around this to mount a monitor flush to the front panel. The actual LCD sits about 5mm behind the plastic. The only solution would be a non-touch LCD with an external touch panel.

Regardless, I love the quirky old late-80's LCD, even if it is not as functional as a modern system, it is certainly more impressive. I run a dateless license plate on my car, and so far no passenger has even come close to guessing the cars age after seeing the tech inside.

As for irreplaceable parts, the entire suspension (pump, struts, valve body, computer, G sensors, gyroscope (actually a vibrating pendulum), front and rear lower control arms) and steering (front steering rack, front slave rack, cable system, rear steering rack, rear hubs, computer, yaw rate sensor, pump, steering column with integrated steering angle sensor) system is unique to the 872 UZZ32s.

As is the alternator, AC compressor, timing cover, oil filter mount on the engine. The longblock is the same as other 1UZFE motors, with one less stud near the oil filter. Replacement engines can be fitted provided that this stud is removed, although the complete front end will need to be swapped over. The ECU is unique to the UZZ32 as it communicates to other systems, but you can mount a UZZ30 or 31 motor to a '32 ECU and vise versa, depending on the chassis. LS400 motors would need a Soarer loom, as the wiring is different at the ECU end (4 plugs on the LS400 instead of 3 on the UZZ3x). Soarers do not have EGR, so the upper intake manifold would need to be retained (trivial) if an LS400 motor is used to replace a broken UZZ32 motor (rare, 1UZs are pretty unkillable).

The display binnacle, rear subframe, washer bottle, PS fluid reservoir are unique to the UZZ32.

The EMV, sonic mirrors, reversing camera, hydroboost ABS brakes are all options on the UZZ31, but standard on the UZZ32. This makes them easier to find.

gently caress.

wallaka
Jun 8, 2010

Least it wasn't a fucking red shell

You are a lunatic in the best possible way.

Olympic Mathlete
Feb 25, 2011

:h:

Knowing that there's so many unobtainable parts on these just makes me want one more. Probably because I'm an idiot.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
I have 3 more cars worth of spares, I'll be fine!


You missed this gem just a few weeks back! http://www.ebay.co.uk/itm/262221408462

Seriously, though, go for a UZZ30. Regular coil suspension, but all the other goodies that Soarers have. Much better economy and loads more power than the '32, which is a bit of a boat by comparison (for you US folks, the UZZ30 is pretty much a RHD SC400 that was only built until 1993 so missed out on VVTI and the 5-speed).

The '30 is hard to find, though. Most V8 Soarers were '31s, which are fine until the air bags fail. But then you just put Supra suspension them and remove the air system and have a blast.

Pomp and Circumcized fucked around with this message at 15:26 on Jan 20, 2016

Olympic Mathlete
Feb 25, 2011

:h:

I'll keep an eye out, I'm stacking cash so assuming I'm not going to get bummed on insurance I'll bear one in mind because I'm drawn to how luxurious and unassuming these are. The one I posted up previous went for under £1000 on ebay too so they don't appear to be costly at all but I imagine they're superb fun when they start to go wrong!

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
Just go for one with a decent body, a not-delaminated windshield, and if you're lucky, some dumb simple mechanical fault that pushes the price way down. A friend bought a £400 Soarer from ebay with 'wont charge the battery SPARES OR REPAIRS BRO', car was mint, and a £100 alternator later, and he has a great car.

If you're not a huge V8 fan (though these are great engines), then maybe look at the UZZ30. They are lighter, have the equally-legendary 1JZ turbo engine, but have less 'toys' (no leather, no shaky mirrors, no EMV screen, etc). Don't worry about turbo problems too much - most people go for the 2fast2furious mad tyte drift thing with these cars and whack a huge turbo on them, so stock turbos are plentiful.

Note that the V8 Soarers are old-insurance group 20 (the highest), plus they are imports. I pay £400/year for each of mine with Admiral. I'm almost 30 and have 9 years no-claims though. I bought my first Soarer just after I turned 25, insurance was about £800, which isn't too bad.

Pomp and Circumcized fucked around with this message at 19:51 on Jan 20, 2016

Olympic Mathlete
Feb 25, 2011

:h:

Yeah I just took a look at insurance for one and it's sitting about £1000 a year which is annoying considering something like an FB RX7 would cost me not even 1/4 that despite costing more to actually buy. :/

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
Big heavy car with a 4.0l engine can do more damage than what insurance believes is only a 1.3l

Olympic Mathlete
Feb 25, 2011

:h:

It's also because an RX is considered a classic and gets cut rates. I suppose the import status on a Soarer doesn't help matters much either which is annoying. Might have to phone up a company or two and see what they say about it.

meltie
Nov 9, 2003

Not a sodding fridge.

ShittyPostmakerPro posted:

Note that the V8 Soarers are old-insurance group 20 (the highest), plus they are imports. I pay £400/month for each of mine with Admiral. I'm almost 30 and have 9 years no-claims though. I bought my first Soarer just after I turned 25, insurance was about £800, which isn't too bad.

I'm sorry, per month?

Olympic Mathlete
Feb 25, 2011

:h:

A year I'd guess. £400 for all the cars per month?

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
:laffo: why did I write month?

It's per year. £400 per year.

When I was 19 I was offered a good deal on a Mustang GT. The best insurance quote I received was £8000 for a year. Needless to say, I went Mustangless.

Terrible Robot
Jul 2, 2010

FRIED CHICKEN
Slippery Tilde
Just popping in to say how much I still love these cars, this thread, and you for keeping one of these rolling marvels going.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
Just got word of a complete UZZ32, minus engine and trans. Guy wants £50 for the lot. Fuckkkkkkk.

Olympic Mathlete
Feb 25, 2011

:h:

ShittyPostmakerPro posted:

Just got word of a complete UZZ32, minus engine and trans. Guy wants £50 for the lot. Fuckkkkkkk.

How many did you say you had? :v:

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.

88h88 posted:

How many did you say you had? :v:

This would be the third 'complete' car, and would provide a complete set of spares. I would strip and scrap the shell within a week.

Olympic Mathlete
Feb 25, 2011

:h:

Sounds like £50 well spent then.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
I've still got to get it trailered to my house (£150), have it removed afterwards (£??), and find places to store all the parts I remove (ugh).

KozmoNaut
Apr 23, 2008

Happiness is a warm
Turbo Plasma Rifle


ShittyPostmakerPro posted:

It would be a lot harder for me as to retain the touch functionality (actually a matrix of LEDs and photodiodes) system does not exist in any modern devices - trying to convert the output from that panel would be very difficult. A conventional touch monitor would not work as the plastic front 'glass' on the EMV units would get in the way. There is very little clearance around this to mount a monitor flush to the front panel. The actual LCD sits about 5mm behind the plastic. The only solution would be a non-touch LCD with an external touch panel.

I've actually used an in-car computer system that used this technology for touch.

Unfortunately it was a custom-made $10,000 apiece navigation system built primarily for ambulances, and it was 10 years ago.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

The touch screens used by Pizza Hut on their point of sale systems are pretty similar. Some ancient monitors from 3M, IIRC.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.

88h88 posted:

Sounds like £50 well spent then.

Let's find out. Got a transport quote of £100 and a found company to remove it for free (scrap metal for them). I'll give myself 1 week to strip it. Should be easy if I don't get called offered work.

It's a complete car except for the engine. Someone put a jack stand through the rocker (all the way through, holy poo poo, what was it, a bottle jack?!). Both bumpers and front fenders are hosed (not accident damage, just abuse). Doors are 'buggered'. But hey, it's got all the super-rare UZZ32 bits! (except for the struts - those were removed long ago in favour of coilovers, and the PO has replaced those with wooden planks for transport).

Plan is to hope that the following is good:

Front/rear lights
Suspension pump, valve body, radiator/reservoir
Display cluster
Windshield
Electronics (80+ electronic modules in this car)
Body panels (trunk, hood, guess that's it)
Door seals
Interior (leather, carpet, dash, etc)
Radiator
Transmission (can't test this)
Control arms, rear subframe, steering racks

I already have the AC pump and EMV from this very car, which is how I ended up with the offer to buy it.

88h88 go buy a 6M2 green 1991 Soarer with a grey leather interior for cheap because of something dumb like a hosed hood and torn leather, and come take some poo poo off my hands to fix it for free. I only want this car for the active parts and the odd spares.

I'm going to challenge myself to fill a 3 gallon-ish bucket with fasteners.

Pomp and Circumcized fucked around with this message at 22:22 on Jan 22, 2016

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
Looking good!!









Bought my first (cheap as poo poo) sawzall today. Cut a (accident damaged) Soarer rear subframe in half in under 30 seconds. Was pleasantly surprised. Cut out the LCA mounting bits (camber bolts are rust-welded in) and trashed the subframe.

Gonna tear up a car next week. Need to buy a windshield remover. Woo.

Olympic Mathlete
Feb 25, 2011

:h:

What's with the hole on the rear bumper, was this LPG or something? Or is this just one of the million and one wacky system related things on these?

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
It's LPG, yes. Was a dumb mixer ring system but still worth some ££ on eBay. However, not worth as much as a not-hosed rear bumper. Damnit.

I run LPG on my car, but have the filler located where a tow hook would go (under the bumper), which is not as nice to fill up (I often kneel on the fill pipe so I don't get wet knees from the ground), but preserves the look of the car, and would let me take it back to stock with no bodywork required.

Speaking of wacky systems, the retractable antenna looking thing on the front bumper is a (rare UZZ32 option!!!) parking pole, which you can extend to tell you where the front of the car is. With a hood that long (that you can barely see from the driving position), it's a useful option!

Pomp and Circumcized fucked around with this message at 15:00 on Jan 24, 2016

Olympic Mathlete
Feb 25, 2011

:h:

I follow a Honda sales page on facebook and noticed one of those parking poles pop up for sale a few weeks back. I'm not sure at what point I'd ever use one but then Japan installed all sorts of weird and wonderful poo poo in their cars like the two can glovebox fridge in the S13...

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
Yeah but does it have doilys?!?!



This is from a Mk2 Soarer, but the Z30 series (like mine) had them as an option as well!

Terrible Robot
Jul 2, 2010

FRIED CHICKEN
Slippery Tilde

ShittyPostmakerPro posted:

Yeah but does it have doilys?!?!



This is from a Mk2 Soarer, but the Z30 series (like mine) had them as an option as well!

Holy gently caress...I need these for my old Celica GTS...

Also those seats are the best ever, I wish Toyota had never stopped using them in their upper-trim cars.

Das Volk
Nov 19, 2002

by Cyrano4747
Why go to all the effort of converting to LPG in a luxury car?

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
There was not much effort - it took around 4 days, working 4-6 hours per day. Total cost to me was £681 (including inspection and registration), and the system saves me around 11p/mile in fuel (after considering reduced mpg and valve saver fluid costs). I daily drive my UZZ32, doing around 20,000 miles per year. There is no noticeable change in the characteristics of the vehicle on LPG. If anything, luxury cars are most suitable for conversion.

I'm curious as to why you're surprised at this. Is it because luxury car owners generally don't care so much about their fuel consumption? In the UK, it's not uncommon to see larger cars with larger, more thirsty engines on LPG. Most of my US import vehicle sightings have been at the LPG pump.

If it helps, when I converted my car, fuel was costing me $8-$9 per gallon, with LPG costing half that much, on a car which returns 20mpg highway. I charge a set amount per mile by my clients, anything I can do to decrease my direct costs of driving will leave me with more money to spend elsewhere.

My LPG install is next up, I'll detail the installation in my next update.

CroatianAlzheimers
Jun 15, 2009

I can't remember why I'm mad at you...


I'm cofused, these aren't lovely posts at all :colbert:

This is madness, all madness. I love it.

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
If you want to see my lovely posting, you'll need to check the counter-strike threads. But be warned, it's pretty cyka blyat in there.

And thanks :)

Das Volk
Nov 19, 2002

by Cyrano4747

ShittyPostmakerPro posted:

There was not much effort - it took around 4 days, working 4-6 hours per day. Total cost to me was £681 (including inspection and registration), and the system saves me around 11p/mile in fuel (after considering reduced mpg and valve saver fluid costs). I daily drive my UZZ32, doing around 20,000 miles per year. There is no noticeable change in the characteristics of the vehicle on LPG. If anything, luxury cars are most suitable for conversion.

I'm curious as to why you're surprised at this. Is it because luxury car owners generally don't care so much about their fuel consumption? In the UK, it's not uncommon to see larger cars with larger, more thirsty engines on LPG. Most of my US import vehicle sightings have been at the LPG pump.

If it helps, when I converted my car, fuel was costing me $8-$9 per gallon, with LPG costing half that much, on a car which returns 20mpg highway. I charge a set amount per mile by my clients, anything I can do to decrease my direct costs of driving will leave me with more money to spend elsewhere.

My LPG install is next up, I'll detail the installation in my next update.

Wow, so it's even more than when I left a few years ago. I suppose it makes sense when you're doing that much driving. Definitely interesting stuff.

Adbot
ADBOT LOVES YOU

Pomp and Circumcized
Dec 23, 2006

If there's one thing I love more than GruntKilla420, it's the Queen! Also bacon.
OK, LPG install time!

These pictures come from two separate installs. I originally installed the LPG system on the green UZZ32, but ended up moving it to the white UZZ32 a few months later (this was a pain in the rear end and a huge waste of time, but turned out to be necessary.

For those unfamiliar with LPG, it stands for "Liquid Petroleum Gas", and is a mixture of propane and butane (usually mostly propane). The composition changes slightly with supplier, supply and demand, the weather (seriously), etc. It is a product of refining crude oil, the same as gasoline and diesel. It used to be considered waste and burnt off. It is now available over most of Europe. It is considered a 'green' fuel, due to the very low levels of 'nasty poo poo' in the exhaust. The exhaust is very close to pure water + co2. For this reason, it receives a very generous tax break from most governments. In the UK, the price is 'fixed' at 50% that of gasoline, although most gas stations add a few pence per litre because gently caress you.

For cars, it's a great fuel. It has an octane rating of 102-108 RON. It contains less chemical energy than gasoline, 26.8 MJ/litre compared to 34.8 MJ/litre for gasoline and 38.6 MJ/litre for diesel. For this reason, we need to burn more of it, which gives a reduction in MPG for the same power output. LPG's stoichiometric ratio (air:fuel ratio) is 15.5:1, compared to 14.7:1 for gasoline.

99% of LPG conversions work by injecting vapourised gas into the cylinders. This is done by using engine heat to vapourise the liquified (compressed) gas, and then 'injecting' the gas into the intake manifold near the inlet valves. In reality, the gas is pressurised and so will happily flow into the cylinders by itself. The 'injectors' are merely solenoid valves.

As the gas comes compressed from the pump, no fuel pump is required. The fuel finds its own way from the tank to the reducer/vapouriser. Safety valves are fitted at each end of this pipe, and will close in response to ignition signal loss, RPM loss, or the detection of low gas pressure.

A separate ECU handles the control of the LPG system. The installation involves cutting the original petrol injector ground/trigger wires, and splicing the ECU in between them. When the LPG system is not running, the LPG ECU uses a set of internal relays to 'reconnect' these wires. For LPG operation, the relays open, preventing the signals from reaching the petrol injectors. The LPG ECU is constantly reading the attempted petrol injector signal pulses, and uses a map/correction table to provide similar pulses to the corresponding LPG injectors. Once the corrections have been properly calibrated (this is 'learnt' using lambda readings and by testing for corrective action by the petrol ECU), the original petrol ECU will not know that the car is running on an alternate fuel.

If the LPG ECU detects a drop in pressure, sudden drop in RPM, or any fault/missing component, it will immediately switch back to petrol and log the error. Errors can be pulled via proprietary software and a USB dongle. This software is also used to configure the system for initial setup.

As the system requires engine heat to operate, the petrol injection system is still required. Therefore, almost all LPG cars are dual-fuel. They start on petrol, then after a few minutes/miles, when the thermostat has opened and the LPG ECU has seen a rise in coolant temperature at the reducer, it will attempt to switch over to LPG. This can be done all-at-once, cylinder by cylinder, or in batches of your choosing. You can define an overlap period where the car runs on both fuels.

An advantage of keeping both fuel systems is the huge range advantage. You get to keep your original range on petrol (useful if you forget to fill up with LPG or can't find a place that sells it), but can boost that with extra miles on LPG.

Next post: the install! (my fingers hurt)

  • Locked thread