LPG

[stonesie]

Yep, unfortunatly with voltage drop and the capacitance of a lead that long it is doubtful that it will work, i think USB leads are limited to just a few meters for those reasons.

Im no expert on computers and suchlike....... hope that leonardo comes with good instructions

[gareth]

damn, extension lead into the garage then... probably for the best

[handpaper]

According to the standard, the maximum length of an RS232 serial cable is 50 feet, so you should be fine.
USB is much faster than serial (12Mbps vs 115 Kbps) and is thus more sensitive to things like cable length.

Parts for my LPG conversion arriving tomorrow.........

[oze30]

My conversion is getting done on Monday! 60p fuel.. here we come!! (stupid V8 thirst!)

[stonesie]

Todays ebay session turned up a re-conditioned dell laptop for £36 delivered... not as good a bargin as Brianmoooore's but it should do nicely, no cd drive but i can transfer the software over from this pc


LPG, its the way forwards

[stonesie]

WooHoo, i collected it this morning but would like some advise on what parts i can use and what is going to get fragged out on fleabay, also i know theres no backfire valve so im going to have a measure up and see about getting one when i have found a leonardo at the right price.

Pics...










The boot floor will have to come up a bit but ive noticed a hump at the front near the back seats, i think it will be about level with that so thats not as bad as i thought, the filler, i think i will make a plate and hang it from the O/S bumper mount so that i don't have to make any holes in the bodywork, no more vounerable than being mounted on a tow bar but i will put a loop of pipe behind there. Just in case

[gareth]

i can see a catflap type backfire valve... it's on the engine side of your AFM.

love the "NITRO" button!

[Brianmoooore]

As above. Catflap's on the AFM in the first pic. Whether or not it will fit a 320 AFM (or a 325 AFM)is another matter.
The centre hole of the mixer ring looks like it might be a little on the large side for a 320, but it won't do any harm to try it. If the centre hole is too small it will start to affect top end power, but if it's too large, then it won't draw in enough gas to provide a smooth idle.

[handpaper]

My tank and underbonnet stuff is in, just connecting the Leonardo wiring.
The circuit (yellow wires) that interrupts the injector positive (fat red/white wire) looks a bit weedy, would it be useful to have it trigger a relay instead?

[stonesie]

The centre hole of the mixer ring looks like it might be a little on the large side for a 320, but it won't do any harm to try it. If the centre hole is too small it will start to affect top end power,

Being a 320 it can't afford to loose any, i should have had a proper look before saying it had no catflap but it was raining, Handpaper's question is a good one, im not going to be at that point for a few weeks yet though (damn bills to pay)

[Brianmoooore]

The circuit (yellow wires) that interrupts the injector positive (fat red/white wire) looks a bit weedy, would it be useful to have it trigger a relay instead?

Combined injector current is only about 0.5A, so the Leonardo wiring should be adequate.

[gareth]

while on this exact subject, where should i be interrupting the injector wiring?
red/white wire between the main relay and the injectors?

looks a bit more straightforward on the M20 one:
http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig02.pdf ...than the M30 one i have: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig02.pdf as cutting it straight after the main relay will also affect the ABS.
i only ask about doing it at the main relay as mine are tucked up beside the ECU die to their location on the M30 loom. or should i attack it further downstream near the injectors themselves (more work). i'm not sure exactly where the 'tee' joint occurs within the loom...

[Brianmoooore]

Cutting the wire at the main relay will disconnect the power feed to the ICV (don't ask how I know), so the cut has to be made after that tee joint, or run another feed to the ICV.

[Brianmoooore]

Combined injector current is only about 0.5A, so the Leonardo wiring should be adequate.

I slip one in every now and again to see if you lot are awake.
Obviously not! Impedance of three injectors in parallel is about six ohms, so combined current is about 2A.

[gareth]

Cutting the wire at the main relay will disconnect the power feed to the ICV (don't ask how I know), so the cut has to be made after that tee joint, or run another feed to the ICV.

cheers brian, i'll probably attack it within the trunking that runs over the injectors... i'll have a dig about tomorrow. i reckon most of the wiring can be neatly done straight off the back of the ECU keeping extra wiring in the engine bay to a minimum.

hopefully, it'll be done for friday as i'm off into europe with it

[handpaper]

I originally planned to connect everything into the engine wiring loom near the ECU, but it's a lot easier making connections within the engine bay.
For instance, the paired (in a single sheath) brown and red wires for coil negative (for engine revs) and switched ignition could go into the loom near the ECU, but they're paired because that way they cabn easily be attached either side of the coil
Likewise the (also paired) red/black and black permanent live and ground - running them straight to the chassis earth and battery connector is far simpler (and less intrusive if you want to remove the kit).
In fact the only thing I've modified the loom for up to now is the lambda sensor - and I haven't even cut it there. Apparently it works just as well to attach the purple lambda wire from the LPG ECU to the (black) lambda signal wire, leaving the grey wire unattached.
As for the ICV, I've already removed mine (Megasquirt going in soon, which doesn't use it). Its intake boot hole is occupied by the balance pipe to the vaporiser.

Incidentally, does anyone have a Motronic 1.3 wiring diagram? The one in the back of my Haynes (I know, I know) shows a 35-pin ECU connector, I think that's 1.1?

[Brianmoooore]

The diagram in the Haynes manual is the reason I "know" about the red/white to the injectors also supplying the ICV! The Haynes diagram only shows a two wire ICV with no constant power feed.
The 1.3 diagram is available here: http://www.autolib.diakom.ru/CARS2/
The grey wire from the Leonardo is to provide a simulated lambda signal to a petrol ECU when running on gas, to keep it happy in the event that the real lambda signal goes too far out of spec. Only really required on cars that default to 'limp' modes or have adaptive ECUs.

[gareth]

i found the 't' off, it's all within the injector trunking on the M30 loom, so that's now taken care of.
most of the other wiring is also now sorted, just finishing it today hopefully.

a quickie if i may... the leonardo manual calls for a wire to be connected to the "centre pin" of the TPS but does not elaborate on this. which colour should i connect to? (i've got a simple manual TPS on there now) choices are brown, brown/blue or brown/black.

oh, i have three fuel valves i think... one near the front (combined with filter), one on the evaporator, one within the multivalve on the tank. all should be powered from the blue wire. correct?

oh, one last thing, my oxygen sensor is a 4 wire universal jobbie. 2 white wires for the heater part (one ground, one ignition switched positive), and 2 for the sensor part (grey= ground, black = leonardo ecu?) correct?


before i go and fill the thing, any advice? i'm going to stick £5 in it first off, just in case of leaks. that'll be ok won't it?

i'm all excited now!

[Brianmoooore]

. the leonardo manual calls for a wire to be connected to the "centre pin" of the TPS but does not elaborate on this. which colour should i connect to? (i've got a simple manual TPS on there now) choices are brown, brown/blue or brown/black.

The Leonardo is refering to a throttle pot, as fitted to the iS. M20/30s have a switch (there's a software option for this), and the switch you want is the idle one, which will be the brown/blue.

oh, i have three fuel valves i think... one near the front (combined with filter), one on the evaporator, one within the multivalve on the tank. all should be powered from the blue wire. correct?

correct

oh, one last thing, my oxygen sensor is a 4 wire universal jobbie. 2 white wires for the heater part (one ground, one ignition switched positive), and 2 for the sensor part (grey= ground, black = leonardo ecu?) correct!

correct.
There's a school of thought that you should purge the tank of air before fitting the multivalve. I do this by flooding the tank with propane vapour from a cylinder until I can smell it overflowing, then quickly fitting the valve.
£5 fill is a good idea, in case you have to take things apart again. Run it dry (you can feel it running out for about 5 miles), and when you refill, take note of how many litres go in. The correct amount is 80% of the total tank capacity, but providing you NEVER leave the car parked in the sun immediately after filling up, 85% is fine. If you get to 90% and it hasn't cut off, stop filling, use up all the gas, and take the valve out for adjustment.
OT, I've had two barn stored A series Minis running today on LPG. The cars hadn't moved for fifeteen years, so last week I poured some oil into the cylinders via the spark plug holes, and some into the oil filler to get some oil on the valve gear.
Yesterday I put batteries in them, spun them over on the starter motors for about a minute, and today I took off and cleaned up the points (remember them?) in the distributors, checked for sparks and put the plugs back in. The fuel pumps showed no sign of life, and the whole fuel systems appear to be clogged with a varnish like substance from long evaporated four star.
Took off the air filters, removed the dashpots from the carbs, wound the throttle stop screws down, fetched my trusty propane blowlamp, removed the shroud and jet from the torch, and hooked the remains of the torch into the hole where the dashpot came from. Turned on the gas, turned the key, and they burst into life in turn.
They behaved more like diesel engines than petrol, in that I controlled the revs by adjusting the gas flow. I ran each one for about twenty minutes to get them fully up to temperature, and generally blow away the cobwebs.

[Speedtouch]

Nice one Brian, do you plan to restore them?

[gareth]

cheers brian.
i've just called it a day for now. the ecu and most of the loom are all fitted and the dash is back together. i did wire everything round the engine bay en the end. i was hoping to keep it looking standard-ish but with the M30 and LPG pipework, i've lost that battle anyway!
all that's left to do now is to wire in the TPS, level gauge and the tank mounted solenoid valve. then it's fill-up time!

do you think i'll be ok to just fill without purging first? only the pipes are all installed (fillly feckers!) and the multivalve is fitted. also, i have no propane bottles handy.

should the multivalve cut off at 80% full (assuming this relates to a set pressure)?


i like the idea of a LPG mini... i was tempted to convert one as a really really cheap runabout
put a massive cylinder tank in the (already useless) boot and have a huge range between fillups!

[Brianmoooore]

should the multivalve cut off at 80% full (assuming this relates to a set pressure)

Nothing to do with pressure - that varies enormously with temperature. The cut off is a simple float valve, just like in the cistern of your loo, and it may need adjusting (i.e. bending). No way to tell, except by trial and error.

[Brianmoooore]

Nice one Brian, do you plan to restore them?

Eventually, maybe, or might leave it to my son. They're just being evicted from one barn to another at the moment. One is a Mk 1 850, and the other is a 1275GT.

[Speedtouch]

Cool. There's an almost complete (but rusty) Mk1 Cooper 1275S with Dunlop alloys that's been left in an open garage near me for years!

[gareth]

should the multivalve cut off at 80% full (assuming this relates to a set pressure)

Nothing to do with pressure - that varies enormously with temperature. The cut off is a simple float valve, just like in the cistern of your loo, and it may need adjusting (i.e. bending). No way to tell, except by trial and error.

ahaa, gotcha.
hopefully it'll be ok then, it's a new tank and valve from the same manufacturer. only way to see is to try it i guess.

[gareth]

i am cooking on gas now!!!!
all finished, filled with a fivers worth of LPG and i'm away!!!!

i've not attached it to the software to set things up yet but as the kit was off a E32 with a M30B35, i think it's all the same. it certainly runs ok and the level gauge settings seem to work with my level gauge too.

[Brianmoooore]

Cool. There's an almost complete (but rusty) Mk1 Cooper 1275S with Dunlop alloys that's been left in an open garage near me for years!

Criminal!!!

[handpaper]

Finished today about 13:00, popped into the nearest 'gas' station on the way to work and put 5.5 litres in just to check for leaks etc. On the way, out of curiosity, I flicked the switch to 'gas' and she runs!
That 5.5 litres got me all the way to work and most of the way back, roughly 30 miles of (mainly) motorway. So, 25mpg (roughly what I'm getting on petrol).

I filled up properly on getting home - the (52 litre) tank should have cut off at 42 litres, but kept filling. I had to stop it manually at 44, so something still not quite right there.

Even so, 43.95 litres for £23.69

[Brianmoooore]

Tank float valves quite often have to be taken out and adjusted a little to get the correct fill.
The official maximum fill is 80% (about 42 litres), but this is for the absolute worst case scenario. (tank filled, and then immediately parked in the hottest summer sun.)
In practice, 85% (44 litres) is perfectly safe, assuming that you don't fill and do the above.
Run it dry, and fill it to a maximum of 47 litres. If it hasn't cut off by then, then things need to be taken apart to see why.

[handpaper]

Cheers Brian - by 'float valve' are we talking about the sponge-on-a-stick that operates the fuel level sender?

[Brianmoooore]

'Sponge on a stick' is the float valve, but it's no sponge - it's a closed cell foam, so doesn't absorb liquid.
Probably should point out that only toroidal tanks need to be dismantled and adjusted. If you have a cylinder tank, you simply rotate it in it's straps to fine tune the level.

[Speedtouch]

Cool. There's an almost complete (but rusty) Mk1 Cooper 1275S with Dunlop alloys that's been left in an open garage near me for years!

Criminal!!!

It is a sad sight. Story goes, it belongs to foreigners who parked it up in the garage years ago but refuse to sell, so it's just sat there partially exposed to seaside air. A few badges have since gone missing off the bootlid, and someone has sprayed graffiti on the back window. I took a sneaky peak at it, and it's in quite a state but appears genuine, with twin tanks, 130mph speedo, sliding windows, etc. The doors are locked and bonnet closed so I couldn't verify if it has the correct engine. However, the sills and arches are rotten so ideally would need a reshell - assuming the owners could ever be persuaded to part with it

[daimlerman]

Combined injector current is only about 0.5A, so the Leonardo wiring should be adequate.

I slip one in every now and again to see if you lot are awake.
Obviously not! Impedance of three injectors in parallel is about six ohms, so combined current is about 2A.

But Brian,you are NEVER wrong...

[stonesie]

Well after a slight financial hickup i have just ordered the new copper pipe and a Leonardo, 4 day weekend next week so hopefully all the parts will be here and the weather will be ok, Roll on half price fuel

Total spend so far £311

[gareth]

prepare to activate "smug mode"!!!!!