Fitting LPG - hey, it's a gas, man!

[Mazda Man]

On 12/06/2016 at 10:44 PM, Laird_Scooby said:

Meanwhile i think i'll leave it "temporarily installed" in the coon tray and see how i get on with it there

[Laird_Scooby]

Well it will give me time to either get used to it in the coin tray or work out a better place for it. Meanwhile i wish this weather would stop with the flash floods, i'm still trying to get the final tuning done!

[Mazda Man]

Been hammering down in Birmingham since around 2pm....localized flooding...again...it must be summertime!!!  

[Laird_Scooby]

Twenty four hours on and we have blue skies and sunshine here in sunny Suffolk - maybe it really is summertime?!?!?

[Laird_Scooby]

Well with the sunshine etc i managed to get out and do the final tuning, sadly my phone chose that moment to be flat so no video i'm afraid! I will upload a video later as there is a bit of room for a little more tweaking - it's near spot-on but not quite and i think the vapouriser is going to settle and "loosen up" a bit now it's in use again. Put another way, it's not been used for a while, there's a rubber diaphragm inside that no doubt will loosen up with use and being heated again so i daresay it will need a tweak in a bit.

I also fitted a new pair of wiper blades - strange i know that i've included that here but ever since i fitted the last set 2 years ago they have juddered. Always! Even when they were first new and allegedly at their most supple. I even got to the point a few months back of thinking the screen needed polishing (some may remember the thread i started on DIY screen polishing) and in a fit of inspiration (or was it just perspiration? ) i decided to pick up a replacement set of blades - £2 each from Wilkos. Job done! No more judders, squeaks, or other annoying noises even on a dry screen!

[hughezee]

Tuning sounds promising shame about the video but I have had a few moments like that and I've just carried on working, sometimes oblivious to the camera not recording the sound  

[Laird_Scooby]

I didn't quite get that far Stu - i picked my phone up to take out and it bleeped at me flashing up a message along the lines of "Connect your charger - 2% remaining"

There's still a few little tweaks to do so once i get the right combo of charged phone, good weather etc i'll sort the video out. On the whole it's running pretty well as it is, one thing i do need to do is increase the delay on petrol operation during changeover to gas - there's a slight splutter/cough at the moment because the delay on petrol cut-off is currently 0 seconds. I reckon about 0.4 - 0.5 seconds should do the job, keeping the petrol injectors going for that extra fraction of a second should work wonders!

Granted it changes over on a trailing throttle above 1800rpm and falling revs, however on a cold engine this can easily be achieved with the cold start bringing the revs up and only a tiny touch of throttle enough to take the revs over 1800rpm but not enough to alter the TPS signal by enough for the Leo to ignore the change in voltage. This means that not only is it changing to gas with falling revs but the fuel cut-off has come into play as well - all these things combined create a situation where it can easily stall.

[Mazda Man]

Think it's time to buy a few shares in Wilko.....

[Laird_Scooby]

1 hour ago, GeoffPurpleHaze said:

Think it's time to buy a few shares in Wilko.....

Sounds good to me!

[Laird_Scooby]

Naturewatch Update

Remember Mrs Blackbird sitting on her nest in the KV6 spares car? Her patience has been rewarded :

A total of five baby blackbirds! She was off getting some wroms when that was taken, sadly i'd put my phone away when she came back with a beak full of worms as she stopped and posed on the fence just in case!

[Mazda Man]

Awwww,they'll love them wroms.  

[Laird_Scooby]

They will indeed Geoff!

[hughezee]

Makes the death of the spares car justified  well er kind off 

[Laird_Scooby]

I think the bird and her nest is kind of fitting in a way - as one thing dies, so 5 more are born. I suppose by rights it should be a phoenix, not a blackbird

In fairness the death throes of this KV6 825 have been long and protracted. It appears that it was first taken off the road about 5 years ago, while it was off the road the cam belts were done (all 3 of them) and then while waiting for a new windscreen, not only was the rear screen smashed but the battery apparently went flat. From what i can tell, this happened with the keys in the ignition - this locks the immobiliser out permanently on post-96 models unless reprogrammed on Fastcheck/Testbook or the MEMS ECU, CCU, ignition key, fob receiver & fob and transponder ring (mounted on the ignition switch) are all changed for matching units.

This just wasn't possible without a lot of expense and the previous owner (who may have been the culprit for letting the battery go flat with the keys in) claimed he had driven it when he first got it. He also left it laid up in a garage for about 2 years. Meanwhile the sea-breeze effect had a good go at the underside of the car and most of the bolts/fastenings - the exhaust for example was totally rotten and there are several patches underneath in need of welding.

I did bypass the immobiliser but even this only allowed it to run for a few seconds at a time, the engine however was sweet as a nut. Shame in a way as on the face of it it's a car in good condition, when you scratch the surface too many little gremlins appear!

[Laird_Scooby]

While trawling youtube, i found this Fifth Gear clip all about LPG :

 

Check out the exploding Vauxhall Omega!

[Laird_Scooby]

Something not mentioned while doing the main bit of the conversion was the breather hose that connects into the air intake hose between the throttle body and the air filter.

Because of the bulk of the mixer hung on the end of the throttle body, this pushes the air intake hose about an inch and a half away from whee it was when it left the factory.

In all honesty i forgot about it after making a mental note to sort something out until yesterday while driving it and noticed it was smelling very "fumey". Popping the bonnet when i got back reminded me of the most likely cause - and the cause of the occasional whiff of gas after switching off as well!

Realising that bending the breather pipe that far wasn't an option, i had a think. And another one. Then one more for luck!

This is what i came up with :

A 12mm elbow and a length of thin-wall 12mm hose - this was allegedly fuel hose with overbraid.

Fitting it into the hole in the air intake trunking involved nothing more than a firm but steady push :

Likewise the other end onto the metal stub :

During fitting i threaded it through the other hoses and cables :

Pardon me for being a little big-headed (or maybe just proud?) here but i think it's a pretty neat and tidy installation, almost "factory-neat". Admittedly there's a few bits i still want to tidy but they are little jobs for the "fussy cleaning and tidying days" i get sometimes.

Meanwhile apart from the tiny leak on the fill-pipe union (which i think i've fixed but won't know until next fill-up) and the problem of where to site the changeover switch, it's complete and running. Still needs a final "fine tune" (i'll get the video this time, promise! ) and the cat removed but hey, it's done!

Watch out for a (much!) shorter version of this when i fit LPG to Project Galactic Dawn - planning a few nice little touches like a custom-fit changeover switch and perhaps a hidden mixer.

[Laird_Scooby]

Well i had my second fill-up today - 41L (9 gallons) and 189 miles, works out at 21mpg which might not sound all that good .......................

 

BUT ............................................................

 

firstly it was running almost all of that time without the breather connected. Given that the breather fumes form part of the mixture and were to all intents and purposes being wasted to atmosphere, that would account for some loss and probably also for some odd mixture variation across the rev range i've noted on the laptop.

Secondly, the cat is still on it. I know from experience this is worth an extra 15% on the mpg figures on petrol so assuming the same holds true for LPG then i can probably look at it as 24mpg - now beginning to look pretty good which may sound odd but all will become clear soon!

Thirdly, the sort of running i've been doing has mainly been round the village, down to the shop, take the hound for walkies etc or locally (about 6 miles each way) to do some shopping. Normally on petrol i would have got between 25-28mpg on this sort of running. So...........

I'm between 1-4mpg down on what i would expect factoring in the 15% for the cat removal. It's more or less accepted that you get a 5-15% reduction in economy using LPG because it has a slightly lower calorific value than petrol and takes slightly longer to burn in the cylinder. With that in mind, it brings the "real" figure for comparison to petrol to the aforementioned 25-28mpg so 21mpg isn't to be sneezed at!

Besides, at 49p/L instead of 125p/L, the equivalent cost per mile equates to getting something like 53mpg from petrol!

During the fill-up (necessitated by running out of gas on the A428! ) i didn't notice any leaks from the filler/fill-pipe as before. This suggests i was either lucky with my attempted repair or the pressure from the pump at Morrisons in Cambourne isn't quite as high as the one where i previously filled up.

However, i decided to err on the side of caution and have bought a new filler designed for 8mm copper pipe instead of the JIC hoses that the other one (the second hand filler i used from a set of parts i bought) had been set up for then converted to 8mm copper pipe fittings with an adaptor that is where the leak came from!

I also found a nice little 60 degree adaptor designed for fitting to the multivalve that's on the tank for the fill-pipe. This basically moves the position where the fill-pipe connects to the multivalve - remember i had trouble getting the fill-pipe connected and had to draw lines on it with a Magic Marker? This should make life much easier, keep watching for some photos on fitting this and the repair of the filler/fill-pipe together with the video of the fine tuning.

Oh yeah, nearly forgot - i'm wondering if i had actually run out of gas today. As i had been driving a while on the dual carriageway (admittedly the tank was low) this would have removed the gas from the tank. Sounds obvious but that would have reduced the tank temperature as well which would have "shrunk" the tank contents a bit. When i got to Morrisons to fill up i was able to switch back to gas and sat there idling for a while waiting to get to the pump. In the time in between (with no gas going out of the tank) the temperature would have stabilised back to ambient, bringing the volume in the tank back up to a usable level.

Makes sense in theory, whether in practice it will work out i don't know but i suppose i'll find out over time.

[Laird_Scooby]

Well in between monsoon-style downpours i eventually got the new fill pipe fitted. Here's the component parts of the new filler and housing and you can just about see the 60 degree elbow fitting for the multivalve :

New filler loosely assembled but ready to fit :

Old fill pipe removed from the tank and multivalve :

You can just see the inlet on the multivalve but here's a better shot of it from the opposite angle :

The elbow :

............. loosely fitted in place :

............ and tightened to a nice, secure tightness :

New fill pipe fitted after bending to shape :

If you look closely, you can also see i sealed (with RTV sealant) and secured the top-hat with self-drilling screws ^^^^^ At least when the leak showed up the only way it could go was down and out of the tank-vent/gas-tight pipe!

............. and the "business end" :

While forming the fill-pipe and its various bends between the tank, going through the towbar-bodywork gaps etc for the safest, best protected route etc, i must have somehow slightly loosened the nut on the multivalve end of the fill-pipe - either that or hadn't tightened it enough in the first place! I found this out when i came to fill up - luckily i had lifted the gas-tight lid on the tank and sprayed my home-made leak detector spray (strong solution of cheap washing up liquid in a plant sprayer) on the new joints including the filler. The leak came from the join between the fill-pipe and the elbow in the form of bubbles as soon as i connected the LPG filler pipe, purely from residual pressure in the pipe.

As such i abandoned the fill and returned home. The plan was to go straight out with a spanner and tighten the joint but in between landing at Scooby Towers and getting the spanner out, the sky turned black and the thunderstorms started, all 4 of them!

When they subsided a bit i went out and got about 1 - 1.5 turns on the nut, Guy the Gorilla might be able to tighten it further but i doubt it. The proof of the pudding will of course be later today when i try again.

Then maybe i can get on with the final tuning and see if i can find more than 21mpg in there! I'm sure there is more than 21mpg to be had and it's not because i'm driving it "digitally" (two states, either on or off, in other words all or nothing on the loud pedal! ) just because the fuel is cheap.

Strange though it may sound, i'm wondering if maybe i set things up a bit too lean on my previous attempts, this might give rise to a wider throttle opening than is necessary which might cause the timing to retard slightly so that the engine isn't running as efficiently as it should be. I'll have a play and see what happens.

[Mazda Man]

^^^^ haven't a clue what you said there Dave but it sounds good.  

[Laird_Scooby]

Well there's good news and bad news. The fill-pipe is now leak free and i did my third fill-up - that's the good news!

The bad news is, on my way to the filling station (running on the expensive stuff as well!) the engine management light (PGM-Fi) came on again - 4th time in 2 days! Each time it's shown error code 2 which is the rear lambda sensor.

Considering i renewed both the lambdas for the MoT that's what you might call anal analgesia - or a pain in the ar5e! My thoughts yesterday were it was low on gas, a weak or rich bit of gas went through and caused a glitch on the Lambda and because i connected into the rear Lambda that's where the anomaly showed on the OE engine management system.

However, running on the expensive stuff today and it still did it proved there's a problem there.

It could be the sensor was played football with by Mr Postie and his pals when it first came to me.

It could be the sensor was a duff one.

It could also be the fact i had to use a butt-splice (straight through crimp connector Geoff - don't get any funny ideas about butt-splices! ) to connect it to the OE wiring.

Just for fun the listing seems to have disappeared from my ebay purchase history as well - the seller still has listings so maybe they were old stock or a bad batch and they no longer sell them. Could be any one of a number of things, maybe even a combination (old stock, postie played footie with them for example) but i've decided to buy a different, slightly dearer one with a long enough wire on it to cut off the Suzuki connector and fit a new terminal to fit in the OE connector housing.

This should eliminate the Lambda from further investigations, should they become necessary! However, if the Lambda was faulty, it would explain the low 20s in the mpg stakes!

Not really much i can do in terms of either final tuning or shooting a video of the final tune until the new Lambda lands, assuming the weather is ok the day it gets here. Thinking about it, the past couple of times i've connected the laptop the Lambda readout has been a bit odd on petrol, even though the Lambda should have been up to temperature. On gas it's also been trying to enrich the mixture without showing much of a change on the Lambda reading so could well have been a problem waiting to happen. Would certainly explain high consumption!

[hughezee]

Gutted m8 it wasn't a fuel parts lambda by any chance I've have had few listing disappears and suddenly I get a problem with that particular item, sounds suspect to me buddy and your probably right regards a faulty sensor, well hope so and nothing is fouling the sensor and I'm assuming the sensor is out of the main exhaust flow if your running your decat ????????

[Laird_Scooby]

The Lambda landed on wednesday and i got it fitted yesterday after chopping the Vauxhall plug off it (so much for a direct fit on a Suzuki Swift!) and fitting the Rover plug using a new crimp terminal. I took a photo log of this, partly as protection against any warranty claim rejection and partly to show how it's done in a separate thread although some parts will find their way on here!

Can't remember the original make of the first set of Lambdas, this one was RTD i think without checking the box. Have to admit, the fact the listings have disappeared suggests it was a bad batch - it came from a NI seller that i've used for years both on fleabay and Amazon. I have had an incomplete order (due to a new staff member and a profuse apology!) and one warranty claim, both of which were dealt with promptly, courteously and new parts provided and a refund!

The sensors both stay where the factory put them Stu, the decat is simply a Rover silencer that fits in place of the original cat and even looks similar but is obviously much higher flow, hence it releases 25bhp (Rovers figures) by not strangling the engine! Don't forget it's the older style system with no post-cat Lambda, the same as the original (KA4?) Legend so the Lambdas are in the "cast log" manifolds just above the flange where they join the downpipes.

I've not yet looked to see if the cat has collapsed internally but the difference the new Lambda has made is very noticeable, the car is much smoother, quieter and responsive, not just on petrol but gas as well. Also when i fitted the decat, i checked the downpipe nuts because i found something odd on the cat. One dowpipe nut was a little loose causing a slight blow, the others not so. On the cat, all 5 nuts were loose and the 6th was completely missing! Bearing in mind they were tightened to about 45lb/ft with the system/cat hot (i believe the official figure is 35) they shouldn't have worked loose by themselves. As such i wonder if someone was trying to pilfer my cat. This could have contributed to my poor fuel economy and also to the LPG system trying to enrich the mixture at 3000+rpm and a lean mix between 2000 - 2500rpm.

If things go according to plan tomorrow i should be going to the monthly Rover meet so i might take the laptop with me and check the LPG calibration when i get there. This will give me an idea if things have changed as the current default value for the actuator is 79 - this is the position the stepper motor goes to on idle and tries to maintain while driving. The ECU self-learns the best position over time so if it changes it will show that the new Lambda is doing something different and also that the exhaust blows made a difference to the running.

If i'm up early enough (and energetic enough!) i'm planning an oil/filter change and an ATF part-change as well before i go. The ATF part-change is now long overdue as it's only the second one - that said i've not done many miles in it so shouldn't be too bad.

[Laird_Scooby]

Well as promised here's a load of pretty pictures taken during renewal of the Lambda sensor. It's barely possible to see where the sensor is when it's installed so no photos of that i'm afraid - hopefully the others will keep the photo-lovers happy though!

Firstly i have a couple of pictures of the old and the new - there isn't a listing any more for the 827 and/or Legend 2.7 that i can find so i had to rely on an alternative fitment. It's the same sensor with a different plug on it, sold as a "direct fit" for a 1986-91 Suzuki Swift 1.3 :

The new one is still tucked into the Lambda socket used to remove it but the plugs are obviously different. Here's how they are different and although it can't be seen, there is a single round pin in the new one :

First thing to do is pop the seeal out of the back end of the Rover plug :

Then insert a thin, flat bladed screwdriver into the back of the plug to release the tang that retains the crimp terminal inside :

You can just see the tang in this shot :

..........and the connector on the old lead, complete with seal still on the wire :

Cut the crimp terminal off to recover the seal................

................ then amputate the Vauxhall plug (from a Suzuki direct fit??? ) from the new sensor...........

...............put the seal onto the new wire.................

Slide the nylon sheath down the wire and tie a knot in the wire to keep it there :

This gives room to work on the wire..............

Untie the knot and slide the seal and sheath back up :

Put the new crimp on the new sensor wire into the plug housing...........

............... and push fully home :

Then push the seal into the back of the plug :

Job done and ready to fit :

The sensor manufacturers usually put a dab of some sort of anti-sieze compound on the threads but it really is only a dab so i prefer to add some copper grease to the thread using a paint brush to avoid overloading. Also i smear the "O" ring seal on the plug with Vaseline (where's Geoff??? ) to help it slip in (ooo-errr Geoff! ) and seal properly. Without some sort of lube on the "O" ring, it can easily catch and twist as it is pushed home - this is why a smear of clean engine oil goes onto the seal on the filter when it's changed to prevent the seal snagging.

So there you have it, how to fit a different connector on a Lambda sensor!

[Laird_Scooby]

Well i filled up again today, figures on the face of it very disappointing (119.7 miles on 29.3L or 6.5 gallons) but when a few other things are thrown into the mix, not quite so bad.

First, i've been hoofing it a bit since fitting the new Lambda, just to see how it goes. All good on the performance front although every once in a while it hiccups under hard acceleration - whether that will disappear with time or if i'll never find the cause is hard to say at the moment.

Second, i had the engine running for quite a while getting the decat box tight and sorting the downpipe nuts then again today for a bit of fine tuning. Only a bit as it was just about there - the default value had raised from 79 to 84 suggesting it is now running leaner without the cat. Also the progression between idle bypass and bias adjustments was smoother without going horrendously lean at about 1500-2000rpm. I did a short video of it (which i need to upload tomorrow) and waffled over it pointing out a few things that were happening. After the fine tune, i was going to take another video of it idling but it was so smooth, nothing was changing - it just sat there at 700rpm ish with the stepper motor at 84 and the Lambda bang in the middle or just under so a smidge lean of stoichiometric.

All in all, i reckon i had the engine running without doing any distance for about an hour, hour and a half so probably used about 1.5 gallons of gas in the process. This would mean i had done that 119.7 miles (let's say 120 to keep the figures easy) on 5 gallons so 24mpg. However, the first 20 ish miles were done on the old Lambda with the exhaust leaks so at best would have got 21mpg and would have used a gallon. That leaves 100 miles on 4 gallons or 25mpg - still a bit short of what i'm hoping for but comparable to petrol use for similar journeys, especially with hoofing it like i was!

I'll report back with the next fill up and see how it's doing with mixed, more "careful" driving.

[hughezee]

Good progress buddy, looking forward to an update