Garvin wrote:

Have changed many diffs in my time but all have required thrusts/preloads, backlash and pinion to crown wheel measurements/adjustments et al to be made. Usually meaning the damn thing has to go in and out at least three times! This looks to be pretty simple in comparison . . . except for the weight issue. I do have various jacks to help on that score though.

Thats a function of the design. Theres essentially two common ways to build a diff.

On some, (Ford Atlas or Landrover Salisbury for instance) the cast part the holds the pinion and centre bearings is part of the axle case. On those, you have a removable rear cover on the axle case, and then need to load a bare diff into the axle case, and thus need to setup all the preloads and pinion engagement etc.

On others, like the P38 (and other Landrover Axles), or the Ford English or 9", the cast housing holding all the bearings is a seperate piece which bolts into the front of the axle case. With those, you can thus have the cast "pumpkin" all setup ready to go so it just needs to be installed into the case.

I guess you've just been unlucky to have always had the former style.

Ofcourse, to fit the actual diff into the cast part still requires the same work. The advantage being you can easily ship the bolt-in cast housing and thus have someone else do the work for you, rather than having to ship the entire axle.

Under heavy shock loading (think low range, big knobbly tyres, offroading) the rover diffs suffer from flex in/around the pinion support bearings. This causes the pinion to move away from the crown wheel under load which increases wear, and in the worst case, it can move far enough that it jumps a tooth which is likely to break things.

The pegged diff adds a "bump stop" essentially behind the pinion, to limit how much it can move under extreme loading, making them much stronger for extreme use.

If its a road car on standard tyres, its unlikely you'll need a pegged diff.

Finally got the other bank off. Cyl 8 was fully steam cleaned on this bank. Oddly enough thats also the cylinder that fouls its plug with oil. Valves were even covered in horrible rusty deposits.

Drivers manifold fought me the whole way, one of the bolts rounded off, ended up removing the head with the manifold (which was also a challenge getting the head bolts out with the manifold in the way...)

Found that despite internet lore suggesting they are metric, both the new heads from the Thor engine, and the old (replacement) heads used 3/8UNC threads for the exhaust manifolds. Both were dated "00" on the castings, so they're both from 2000ish. So i've had to order up a set of new bolts for those. One of the manifolds also has a cracked Flexi, so i need to do something about that.

Two of the cylinder walls looked somewhat unhappy on this bank, sorta marred up and definitely not the usual shiney crosshatched look.

Oh and ofcourse the lifters are all dished and the camshaft looks a bit crap, as expected.

Not sure how to proceed, on the one hand the camshaft does need replacing, on the other i'd be super pissed if i replaced it, built the engine all back up and discovered it was still leaking coolant...

I think i'm leaning towards just putting it back together and see how it goes. If the head gaskets have fixed all the coolant issues, then i'll need to pull the top off again and do the cam and lifters. At least the actual heads (and those bloody manifolds!) dont have to come back off for the camshaft work.

i imagine a lot of these cleaners are somewhat snakeoily...

On mine, i found the injectors from a Rover K series were a direct fit and had similar flow characteristics, while being a much more modern design with better atomisation etc, so i just swapped them out. I can dig out the part number if you like? Was cheaper than paying to get the old ones cleaned.

Just checked. There was some sort of headgasket failure circa May 2000 at ~91k miles, it appears it was recovered to landrover cardiff and they replaced the heads with new units, but recommended engine block replacement due to "hot spots and scoring on the cylinder block". Its quite hard to make out all the details as the invoice is a fax on ancient faded thermal paper. However you can make out the basics and theres a charge for two new heads etc.

Then October 2000 there is an invoice from sheffield landrover, who replaced the short motor, along with all the gaskets etc that you'd expect.

Oddly enough, the car had only done 10miles between the original failure, and the Sheffield invoice.

It was rebuilt by landrover sometime around 2000ish I'd need to dig out the receipts, but i think they replaced the heads then shortly thereafter replaced the shortblock. Dont think its been touched since then though.

They were pretty tight, needed breaker plus cheater to crack a lot of them off.

Dont do a lot of mileage TBH. Few thousand miles a year.

I guess i clean everything up and reassemble with the new heads and fresh gaskets and see what happens. If its still leaking coolant then give it a dose of water glass.

I held off from using it before as i had the red long-life coolant in it, apparently its incompatible with that?

someone on another forum suggesting that these marks are potentially signs of liner leaks:

I've pulled the passenger side head (drivers ones proving to be annoying!) but i'm curious about some of the findings.

The engine was pressurising the cooling system, slightly, and using coolant, but drove fine and you could do 100's of miles in it a day without issue. Lots of short trips seemed to guzzle coolant, but a long trip would only use a little, suggesting it was leaking more when cold perhaps?

Spark plugs on 1 and 3 would turn orange over time. Its been like this for several years and i've finally decided to fix it as it seems to (finally!) be getting worse with some signs of water on the other bank.

I'm particularly curious having removing the head though, of how exactly its ended up the way it has.

Examining the head and pistons, you can see that 1, 3 and 7 all appear to have signs of steam cleaning, with the clean areas of the piston crowns and clean areas of the head. 5 looks pretty normal.

Moving over to the gasket, cylinder 1 has obvious rust on the firing ring, so we can imagine thats certainly a path between the water jacket and cyl 1. Oddly enough for the cylinder with the most obvious water route, its the dirtiest of the three cylinders. Cyl3 has a small amount of rust on the fire ring too. I guess i'm pondering how water got into these cylinders in the first place to rust the fire ring though... Especially 3, it doesnt appear to be near any water... Cyl 7 fire ring looks fine, infact theres nothing obvious at all around cyl 7, so not sure why its showing signs of steam cleaning. It is ofcourse adjacent to the water jacket, so it certainly could be leaking across from there.

Is there anything else i can check while its apart? Cylinder liners being the obvious question mark.

Ive put a stream of photos on imgur: https://imgur.com/a/PyyyvxJ

Its strange that they seem to act differently...

With mine, with the bad MAF connected up, it would start then immediately die. If you tried to keep it running with throttle it would produce clouds of black smoke and then typically still die a few seconds later.

However if you unplugged the MAF, then some portion of the time it would also start and immediately die, however if you gave it just the right amount of throttle it would stumble then run fine. A lot of the time it would just fire up and run normally.

I drove mine around all winter with the MAF unplugged, sorta forgot about it TBH, and you wouldnt have known for the most part. Then one day, wife drove it to work and it was utter crap. Stalling, stumbling, jolting, basically undriveable. I dont know why it changed. I plugged the faulty MAF back in and it started perfectly and drove home fine. That was the kick i needed to finish the converter though, and with the converter and Audi MAF installed its been spot on ever since.

I've stripped mine just now for head gaskets, was pondering re-routing the coolant for the vaporisor to use the 1/2" feed that used to supply the throttle body... Anyone looked at that route? The mess of T'ed pipes really bothers me, i bought new hoses and am loathe to hack them up, but series mode also gives concern as the vaporisor itself only has 10mm inlets, which feels like it would be very restrictive for the matrix.
Using the throttle heater loop seems like it could work?

I drove my GEMS for months with the MAF unplugged. Ran fine, and fuelling was more or less normal. A bit flat perhaps but certainly nothing untoward.

So yours not running properly with it unplugged suggests something else might well be going on...

With my bad MAF connected, it would often massively overfuel at startup and either chuck clouds of black smoke or not even start at all.

I ended up building a converter to use a MAF from an Audi TT, which has been in for a few months and seems to be working well enough.

I got it off, was definitely a tinting film. Horrible to remove though, it broke up into tiny pieces and wouldnt pull cleanly. Also left loads of horrible residue. Been over it twice with "Elbow Grease" cleaner and a going over with brake clean which has improved things, but i need another few passes over it to get it all off.

Okay. I suspect it's tinted then! Looking out it has a very distinct blue shade.
Must be a professional job as even with the plastic trims off I couldn't see any edge. The only giveaway (other than the peeling damaged but!) Is some halos around the "dots" at the edge of the glass.

I actually quite like the dark tinted look now it's on the car, but given it's damaged and only one window I guess it's better to remove it for now

I've just replaced by tailgate as the old one was rotten.

The glass on the new one is much darker, and has "opticool" on the info plate.

However there is a damaged area about the size of a thumbnail right in the middle where what looks like window tint has peeled off.

Anyone know if the opticool glass has a coating applied that could peel off? Or is it just normal glass and someone has applied standard window tint?

I don't want to start trying to peel it if it's supposed to be part of the glass! But if it's tint ill probably just peel it.

the O2 fault is specifically for the sensor heater. Suggesting either a wiring fault or a dead sensor.

The more you look into it, the less it makes sense.

For some rough figures, charging a battery and driving and electric motor from your electricity is around 90% efficient.

Using that electricity to create hydrogen, compressing it, shipping it to somewhere near your house and then transferring to your car, and running it thru fuel cell to power an electric motor is about 30% efficient.

So even if all those intervening steps cost nothing, it's 3 times the energy (which in the real world means cost).

Burning the hydrogen is even worse as instead of the fuel cell your using a combustion process which wastes 60-70% of the energy. So your down to what, 10% total efficiency compared to the simple battery EV.

Additionally, storing it onboard the car isn't easy, it requires special pressure vessels and the result is poor capacity to volume. A fuel tank can be moulded to fit under the seat etc, can't do that with a hydrogen tank. So even if you magically made loads of the stuff for nothing, fitting it all in a car to give even a couple hundred miles of range isn't possible, especially if your burning it rather than using a fuel cell.

The main use I can see is doing something with actually free energy. For example wind turbines and solar farms offen get pushed into "curtailment" which is essentially a mechanism to balance the grid by turning off generators. If you could instead divert that energy into a hydrogen electrolyser and store it up, it's literally free hydrogen. Nowhere near enough for the countries transport needs but still potentially a useful storage method for medium term energy storage.

Hydrogen for passenger cars is a white elephant.

The only reason its being pushed is the fossil fuel lobby wanting to keep their monopoly on transport. The vast majority of Hydrogen comes from steam-reforming natural gas.

Burning hydrogen is even more nuts than using it in a fuel cell. You put a tonne of energy into splitting the gas into hydrogen in the first place, then just burn it? You'd be far better off just burning the natural gas you started with, and its easier to move around and store.

The only place i see it being actually feasible is in things like marine or aircraft. Maybe some heavy vehicles in certain locations.

The fob is broken on my '94. It works fine with the key.

The only time problems start is if you lock it with the fob.

If you lock with the key, then it will unlock with the key and start just fine.

If you lock with the fob, and then unlock with the key, you end up immobilised and need the EKA.

At one point i was locking with the key and unlocking with the fob, that also worked fine, however at some point the BECM went in a huff and stopped listening to the fob and i gave up trying to get it working again.

Dragging this up from the depths...

In short, its working!

I'll need to upload the code to github or something.

In essance, the arduino reads the output from the Bosch MAF on one of its ADC inputs, uses that to lookup the correct value in a lookup table, and then sets the DAC output to the required voltage.

The Arduino's 5v regulator sends a 5v reference to the bosch MAF and to the DAC board. I've also incorporated a 9v DC DC converter on the input to the Arduino, just so its not having to deal with full alternator voltage (the included linear regulator has a max input of 15v).

Connected it up yesterday, and it works, drives great, if anything it feels a little more snappy on the throttle, lets hope it keeps working :)