the clones are universally reported to be shite, but i dont have a problem spending £80 on a genuine Bosch unit. If the Sagem MAF was similar money, i'd just buy one and then i know its right. But they're somehow £800... Insane. For £800 i could rip the whole lot out and fit something like Emerald!

The MAF sends a voltage to the ECU. The ECU has a lookup table which converts that voltage to an airflow figure. The airflow is then used to compute the fuelling required.

Having spent some time messing with tuning VAG group ECU's i know for instance that the bosch MAF's have a curve like this (the scale is voltage against air mass in kg/hr. with a 200kg/hr offset as the sensor can read negative airflow). This table can simply be lifted directly from the ECU programming:

Theres obviously many MAFs and they all have different curves, the chart above shows a few different VAG models, but the data is fairly readily available, and using that data we can immediately lookup a MAF voltage and know the airflow that voltage represents.

A similar table will exist for the Sagem 20AM but finding it is proving elusive.

If you knew the table for the Sagem, you could get a simple arduino or similar, to sample the input from a chosen Bosch maf, lookup what the sagem would be outputting at the same airflow, and then output that voltage to the ECU.

We could then purchase a cheap £80 Genuine Bosch MAF and bin off the knackered used 20AM's. Unfortunately such tuning information doesnt seem to be available for GEMS. I presume a few people have figured out tuning GEMS, but typically info like that is kept supersecret.

The boots were all split on them and the insides were rusty. They would creak when you turned the steering. So defo gubbered! Hope it makes an improvement with how it drives because it was certainly a bit wandery before

Still not fixed this yet, been working on the balljoints in the other thread, but very peculiar yesterday morning...

Its not moved in 3 weeks since it failed the MOT. Jumped in and fired it up to move it out of its parking area and onto the driveway. Now usually, it fires up very slightly lumpy, and needs a wee rev to clear its throat. However yesterday it fired up running on about 5 cylinders, coughing spluttering popping and farting and generally really unhappy. revving it didnt clear it, and it filled the street with smoke (blue to begin with, then black) I ended up moving it by holding the throttle open, and using the brake to control the speed.

I did find a minute to check the fault codes. It said "amfr correction at its maximum negative value"

Another bad MAF?

MAF was dead when i bought the car, and it ran ok cold, but stopped once hot. Unfortunately genuine ones are about 5 million quid, so the only option was to buy a used one, which appears to have now also died.

I was trying to find someone who could provide the MAF translation table from the ECU. If we know the voltage vs airflow curve, it would be very possible to engineer a replacement using a common modern MAF sensor. Unfortunately i found nothing.

Cheers for the help guys. Back at it this morning and got them out. Tightened the thing even more and smashed at it with a big ball pein and it finally let go. The passenger side let go with a bang too!

https://www.dropbox.com/s/dy6sfw41lrosje0/IMG-20180408-WA0006.jpg?dl=0

The tools definately bent now though, refitting the bushes was fun with the bent tool:

https://www.dropbox.com/s/duv3dkxm1j58fhn/IMG-20180408-WA0003.jpg?dl=0

Didnt start out like that, but the end walked across the cup due to the bend and it all ended up cocked over. However all four went in without issue.

I then realised i ordered 4 big nuts for the balljoints, rather than two big and two small, so i now need to get those before i can finish installing the knuckle.

Also need to get axle oil seals, new bolts to attach the hubs (existing ones were missmatching and ended up pretty smashed up), new CV boots, a new ABS sensor (one ended up getting smashed out!) and i appear to have lost a caliper bolt, so i might just replace the four of those as well.

Not finished, but the backs broken, and once the bits arrive its probably only an hour in the evening to finish it off. Slightly annoying the cars now stuck in the middle of the driveway though! I should have parked it further forwards!

The bottom adaptor is too big, however the balljoint sticks thru by about 3mm so pretty sure the adaptor is pushing against the balljoint, not the knuckle. I was hoping to at least get it started moving, then swap it out for a socket or something to pull it the rest of the way thru.

Unfortunately my press kit doesnt have as many adaptors as the one pictured.

Given up for the night.

This is where we are on both sides:

Tightened it as much as we dared, the C clamp is actually deforming in the pic its so tight.

Bashed lumps out of it with the ball pein and its not moved at all...

Bleh!

Yeh i figured out the jacking the body earlier, wound the C clamp up as much as i dared with a 3ft breaker bar, but its not shifting. Not tried shocking it yet though.

So the car is being awkward as usual.

Started the front axle balljoints this morning and its fought us the whole way. getting the hubs off took what felt like hours of beating, one oil seal is ruined, and i smashed both CV boots so those are also wrecked.

Then started on trying to break the tapers free on the balljoints... The top ones came free easily enough but the bottom one wouldnt shift. I've ended up grinding the balljoint cone off, then taking the knuckle to the bench and smashing it out with a lump hammer.

So finally we're at the worst bit of the whole thing, pressing the balljoints out. I ordered a big G Clamp style balljoint press and it fits well enough, but i cannot get the balljoints to shift. I've tightened it to the point the spanner jaws are spreading and slipping off the hex and theres been no movement at all. I cant get a socket on because the clamp is hard against the arch liner.

Anyone got any pointers to get the balljoints moving? Theres a few guides floating around that seem to cover reinstalling them, but the removal is glossed over...

Yeh the guys know i fix everything myself.

I've not had a chance to hook it up, and i'm away this weekend, but next week i'll get nanocom out and see if there are any faults first off, and also if the lambdas are switching as expected.

There was no lambda figure on the sheet, just HC and CO, and it had "non-CAT test" across the top. The limits were also the 3.5% rather than the 0.3% it would have got on petrol so i'm pretty sure the machine was properly setup for LPG.

I've tried a few round here and this one is pretty good. the others always pluck bullshit fails out their arse and are generally not very friendly. One failed me for not having a Cat fitted on my Audi, i literally stood there like WTF, then pointed at the Cat in the engine bay and said "whats that then?".

Sure, he missed the balljoint, but its very hard to see (the boot has split around the wire retainer on the inside) and as people who've worked on these will know, the balljoints are particularly difficult to feel play in compared with a normal car.

Why would i want my failure list to get any longer anyway? :P

Well the old bus went for its MOT the other day and failed:

Not entirely surprised, as the front balljoints are knackered. Amusingly, they only picked up one, and it wasnt the one that i'd identified myself. So i've ordered a set of balljoints and a press kit to sort those.

Number plate is easy enough to fix, although the holders are very yellowed. I believe its just a 501 wedge bulb?

Which leads us to emissions...

Last year it was an absolute nightmare getting it thru the emissions test. LPG was broken so it was being tested on petrol, meaning the harsh CAT test with its 0.3% CO limit was being applied. It had a faulty MAF and a missfire (which is why it had been laid up for so long) but eventually i replaced the MAF, Both lambdas, all 8 injectors, spark plugs and a few other bits, and finally got it running nicely, and it passed the full CAT test on petrol.

I've since fixed the LPG system by replacing the injectors and re-calibrating, and for the most part it runs and drives perfectly well on LPG. However it failed the emissions test on LPG this time round, managing 3.87% CO against a limit of 3.5%... Waay over what it managed last year on petrol.

I dont understand why the CO is so high. Its running closed loop, so why is the lambdas/ECU allowing it to end up so rich?!

i doubt it would cause an airlock tbh, the large bore pipe from the manifold to the radiator is right next to it, and the radiator has its own vent line back to the tank.

i just removed mine and blanked off the manifold outlet.

when i press the rear wash theres no noise at all, If it was a blockage i'd expect to hear the whirring pump? The front wash pump is clearly audiable.

The front wash pump is also pretty pathetic, so i might swap that out as well, it barely piddles out about 3" up the screen.

thanks, thats perfect :)

I've got what i presume is a duff rear pump, and i've also got a washer pump or three from various cars i've broken, just trying to figure out if they'll work before getting in about it.

Anyone got a spare washer pump and can measure the diameter of the spigot that goes into the side of the washer tank?

Cheers

As a random aside, a few weeks back i was towing a trailer home in the snow, and randomly got an EAS Fault out the blue shortly after leaving the mother in laws. First time its ever had a fault, and i was expecting the worst, bumpstops etc while towing wasnt going to be pleasant...

However all it did was light up the four lights on the height button... No "35mph" warning or deflate to the bump stops, it just sat where it was. I drove a short distance to find a safe place to stop and got nanocom out (luckily it was in the glovebox), it said front right height sensor had some issue. Reset the code and everything returned to normal and its not come back.

If theres no pressure in the tank then i imagine the nanocom "raise" button wont do anything...

Mine seems to lose pressure in the tank when parked for a while. The bags themselves are fine, and dont deflate by themselvs, but sometimes it will do the EAS dance and self level itself right down, or perhaps you'll load a lot of weight into it, and after starting it up it does take a while to raise itself, when really the tank should be full and it should lift immediately. If its only been sitting for a few hours, it will usually lift straight away.

I've never really investigated too closely.

the brrr/clicking noise is probably the ABS firing up because it thinks a wheel has locked.

I've had this before on another car and it was due to a cracked reluctor ring on the CV that the ABS sensor reads. The sensors produce a voltage spike as each "tooth" passes the sensor, and at low speeds this voltage gets smaller. If the ring is damaged or corroded, or the sensor air gap isnt right, the signal can get so small at low speeds that the ECU can no longer detect the pulses and thinks the wheel has locked, and so fires up the ABS trying to fix it.

On that car, it was possible to use the diagnostic computer to view the individual wheel speed sensors, and then driving along very slowly at like 5mph you could see one wheel wasnt reading properly, but if you sped up even to 10mph, they all started reading correctly. When i took it apart the reluctor ring on the CV had cracked due to rust. You could buy replacement rings for that model, but i had a spare CV so just swapped the whole thing out and that was it fixed.