If the brakes are working fine, then it isn't the ABS pump or accumulator. If they fail you need both feet on the pedal to stop the car. Highly unlikely to be a dashboard fault.
What diagnostic computer is your garage using? Unless it is a dedicated LR one for the P38, it won't be able to read the ABS system.
34-37 is correct, when revved the intake manifold wouldn't have any vacuum in it so it should stay at that, it will only drop on the overrun when there is vacuum in the intake. It should also stay at the specified pressure at a constant open throttle.
It will raise the fuel pressure although you've already checked it and it was correct? It might be worth seeing what the fuel pressure is with the return clamped.
It should never go as low as 0, that would suggest an air leak on the intake. When up to temperature it should sit at around 20-30 at idle. It opens up when the TPS shows you've opened the throttle a touch so it allows extra air in (rather than just relying on airflow through the throttle butterfly) to raise the revs. Is the anti tamper plug on the idle adjust missing? That would suggest someone has been in there playing with it. To bring the stepper back into play it needs screwing in to reduce the amount of air that is going in. I don't remember the exact size but it is an Imperial hex key.
It shouldn't do that, if anything it might go open loop at idle but stay in closed loop under normal running. It sounds very similar to how the 4.0SE I bought was running, that had lumpy idle and would sometimes die when stopping at lights (I was knocking it into Neutral and left foot braking so I could keep the revs up to stop it dying on me). As well as the lambda sensors, someone had turned the plunger on the idle air valve so broken the clip that stops it from rotating so rather than the stepper motor moving the plunger in and out, it was simply rotating. However as you've already replaced that, it can be discounted.
As it hasn't been run much since they were last reset, it shouldn't matter and once it has been run for a while they will adapt anyway. Is it staying in closed loop or going open? If in open loop (ignoring the output from the lambda sensors) it will default to zero and stay there. Normally the only time they go open loop is on the overrun or if the ECU has detected something it doesn't like and decides to go to a default fuel strategy which is always slightly rich to prevent engine damage. Your best bet is to try and hold it at 2,000-2,500 rpm and watch the lambda sensor outputs and short term trims. Neither should stay steady, as when the lambda sensor shows rich, the short term trim will go negative until it starts to show lean then it will go positive and it should continue to flip flop between the two extremes.
Yes, the fuel pressure is a constant and amount of fuel that goes in is dictated by the length of time the injectors are open for. That is taken from the various sensors but primarily the MAF and throttle position sensor and the ECU uses a look up table to decide how long the injectors need to be open for (anything between 3mS and 15mS) under all different revs and load conditions. The lambda sensors are there as a final check so if the fuel pressure is slightly high or the MAF is reading a bit out for instance, the injector pulse duration is varied slightly to keep the mixture correct. That is the short term trim, so a little bit longer or shorter to keep things correct. If the short term trims are always going one way or another, the long term trims change to get the short term trims back to wandering either side of zero.
I recently bought another '98 (a 4.0SE) and had to drive it about 80 miles home. It didn't idle particularly well but seemed fine when being driven until I got within 15 miles of home when it started to misfire. As I had the Nanocom plugged in, I reset the adaptive values which made it much worse. It ran like a dog unless I was flooring it and the report from my missus who was following in my car, it was belching out black smoke (rich), stank of petrol and while the trip computer had been showing 21 mpg up until then, it had dropped to 16 mpg by the time I got it home. That showed a permanent 5.0V (lean) on both banks yet it was running like it was rich and the black spark plugs confirmed this. I found one lambda sensor was dead and the other one had one of the pins pushed out in the connector so it wasn't giving a reading. That is something else you could check, unplug the sensors and make sure all of the pins are there and none have been pushed out of the housing or are bent.
Short term trim staying it -25% suggests the mixture is rich and it is trying to correct but that would also suggest that the lambda sensors are showing permanent lean. It might be worth putting a multimeter on the output of the sensors to see what they are actually reading rather than what the diagnostics are showing. Easiest place is on the back of the plug into the ECU, LH bank (bank 1) is on an Orange wire on pin 34 of C507 and the RH bank is on a Blue wire next to it on pin 33. C507 is the red (middle) plug on the ECU. A lean mixture will show as near to 5V while rich will show as near to 0V.
After the reset do all the long and short term trims go to zero? Which is it that is staying at -25%, long or short? What should happen is that the long term trims should be at zero, the short term trims will vary either side of zero going on the output from the lambda sensors. If the short term trims always go one way or the other, the long term trims will alter to bring the short term trims back to moving either side of zero. Whether or not your reader can display it, there is also a figure for AMFR which is a correction added or subtracted from the output of the MAF sensor so that will be read correctly. On my two GEMS cars both MAF sensors give slightly incorrect readings so one has an AMFR of around -2.3 while the other is showing +4.0. When the adaptive values are reset, these reset to zero but will be learnt when the engine is running. The Nanocom allows these to be written in to give a baseline starting point rather than starting from zero
Assuming your reader is converting the 5-0V reading into an OBD2 compliant 0-1V reading, the short term trims should be changing. When showing 0.14V, the short term trims should go positive (lean mixture so the trims put more fuel in), when showing 0.61V, the trims should go negative.
What are the long term trims showing? If the adaptive values have been reset, they should be showing zero. One thing does spring to mind though. On a GEMS, the adaptive values won't reset unless you have at least a 1/4 tank of fuel in the car so it doesn't reset anything that could have been caused by a low fuel level. How much is in it and have the values all reset to zero?
Land Rover don't manufacture the lambda sensors (in fact, like all manufacturers, they don't manufacture most bits, they just bolt together bits from other suppliers), they will be made by someone that specialises is that particular component and given a Land Rover part number. So AMR6244 may be FAE77350, NTK0475 (NGK0475), Walker 250-24512 to name just a few depending on who made it for them. If the plug is correct, it will be the correct part.
What does live data show from the lambda sensors show when it is running rough compared with what it says when running correctly? When you let off the throttle, it will go lean as the injectors are cut off on the overrun to save fuel and give better engine braking, so try to check it when accelerating if it is running cleanly then.
Pete12345 wrote:
Yes Gilbert, I know it's wrong !!
Technically it is but any system where the refrigerant has leaked out is full of air so it isn't any different. Strictly speaking the dryer should be replaced but even if it isn't, it'll still work, maybe not at optimum, but it will work.
You are quite right though. I saw a survey that had been done recently on the practical skills of people broken down into age groups. It was things like can you hang wallpaper, can you wire a 13A plug, can you change a tap washer, can you change the wheel on your car and so on. What they found was that the vast majority in the 50+ age group answered yes to almost everything, those in the under 30 age group answered no to almost all of them. It isn't surprising there are so many cowboys about these days as there is a rapidly diminishing number of skilled (or even semi-skilled) people about as the younger generations would rather learn how to sit behind a computer rather than go out and get their hands dirty doing something practical.
You probably could, most DIY competent people over the age of 50 would be able to do it, only problem is getting the units. Due to them being charged with Ozone Depleting gases it is illegal for anyone to supply to a non F-Gas registered person. Then it needs to be commissioned by a qualified person too and there's the kit you need to install and test them which cost me over a grand for the bare minimum. There's a couple of dodgy suppliers you find on the internet that will supply to anyone (they've already been prosecuted twice but just pop up with a different name) but they supply some really horrible Chinese made units that I doubt will last much more than a couple of years.
I've installed quite a few systems in living rooms but whether it is really worthwhile I've no idea. The customer wants one in the living room so that is where I put it..... My daughter has found that if she leaves the bedroom units on at 21 degrees and leaves the doors open, the cool air falls so they cool the whole house.
That's a bit sneaky, if you don't get anything in the post in 28 days, they didn't get flashed...... We've all been bitten at some point, which is why I do everything myself and don't take it in to anyone. I started playing with engines when I was 11 (I'm now 68, 69 later this month) and have always tackled most things on cars and bikes. So mechanics was my hobby but work was radio communications and electronics until I retired just as lockdown started, which was a bit of bad planning but when I'd put my 3 months notice in, nobody knew what was to come. I'd intended getting a part time job (van driver for Euro Car Parts or one of the other local motor factors was high on the list) to top up the (pretty decent) pension until the State pension kicked in but lockdown killed that idea. Those that were still working were working from home, including my daughter who was using a spare bedroom as an office, and the weather got very hot. She rang me and asked if I could install air conditioning for her. Looked into it and found it was electrics and plumbing, both things I could do, but found that to even buy a unit I needed to be F-Gas registered. A mate had done a course to do car AC just before lockdown and he recommended the same place he had done his course at. I rang them and while the car AC course is one day and a fairly simple exam at the end of it, the full F-Gas for domestic and industrial was a week but, as I had nothing better to do, signed up for it. Did the course and asked what was different in my course to what my mate Danny had done. I had been taught how a system worked, all the legislation involved as well as practical tests whereas the car course just taught you how to do it and why you did it the way you did. So on the last day I did my F-Gas practical test, then the exam, had a coffee then did a regas on my car and sat the exam for the car course, so I ended up with both qualifications.
Put an AC system in for my daughter, two indoor units in the two bedrooms from a single outdoor unit and it was working perfectly. A couple of days later she was on a Skype call with her boss who noticed the AC unit on the wall behind her. Put one in for him the following week. I put a free advert of facebook and it went from there. I won't work more than 3 days a week, ideally only 1 or 2, but it keeps me busy and as each job is different it can be quite interesting at times working out the best way to run pipework, where to mount units and so on.
Another mate is a full time professional musician but as all the theatres were shut during lockdown, he had no work and was asking me about the work I was doing. I told him about the one day car AC course so he did it too. So the pair of them cover Cambridgeshire, Bedfordshire, Buckinghamshire and Hertfordshire. But, not having been taught the theory like I was, I still get phone calls when they find something they don't understand and that is people that have been taught how to do it and not someone who has simply been shown how to use the machine.
Another problem I have found with using a UV light is anti-freeze also glows green. So if you've ever had a coolant leak or spilt any, you'll see green everywhere.
Ooh, 4 hole filled toroidal tank. The pipe coming in from the right is the fill line, that has a non-return valve inside the brass bit so you can fill the tank but if you disconnect the pipe to it, gas doesn't come out. Next to that is the level gauge which is pretty self explanatory, the thing with a red cap on it is a pressure relief valve and the bit on the left is the outlet. That has an electrical solenoid valve in it to shut off the gas outlet as soon as the power is taken off. I'm not sure if a 4 hole outlet has a manual shut off or not, if there is a knurled knob on that bit, it does, if there isn't it doesn't but if the solenoid is disconnected then it can't open. If you want to be really belt and braces, you can remove the small nut in the centre of the solenoid coil and lift the coil off, then the outlet can never open.
If you do decide to remove it, let me know as it would go nicely in the boot of the Rioja red 4.0SE I've just bought (and has been claimed as hers by the other half) as not only was the tank in it fitted the wrong way round, the bodger that 'installed' the system only fitted a 70 litre tank so there's a huge gap all the way round it and it will need filling more often. Not so good now LPG is getting harder to find and the maximum range possible is desirable.
You'll need a pair of these,https://www.amazon.co.uk/Connector-Extractor-Condition-Adjustable-Coupler/dp/B083M2CV1P/ref=sr_1_21_sspa. The standard connection on all AC hoses is a 1/4" flare so you'd need the correct hoses too, although for the price you could even splash out and get yourself a kit like this https://www.amazon.co.uk/KATSU-Tools-Manifold-Conditioner-Refill/dp/B094R8NCVZ/ref=sr_1_5 so you will have the connectors and hoses.
The recommendation is not to use air to pressure test as it will introduce moisture which means you should really replace the dryer. However, there's thousands of cars that have been running around with no refrigerant in them for years before someone decides to sort things out and the while system will have been full of air all that time and a simple regas will do the job.
The only way you can find a leak on an empty system is by putting pressure in it and checking. If they are doing the leak test properly they won't use pure Nitrogen but what is known as trace gas which is a mix of Nitrogen and another inert gas that can be detected with an electronic sniffer. The Kwik Fit and similar use a programmable machine and in most cases have no idea what it is they are actually doing. They connect the machine, tell it what car it is so it can use a look up table to identify how much gas it needs and press the go button. Doing it manually you recover any remaining gas, fill the system with Oxygen Free Nitrogen (that's what it says on the cylinder anyway but if it had any Oxygen in it, it would be air surely?) at 10 bar and leave it for 30 minutes or, if using a digital gauge any leak will be seen in 10 minutes, and see if the pressure drops. If it doesn't then you let the OFN out, vacuum out the system (down to less than 0.01 psi) and fill with the correct quantity of R134A refrigerant.
The difference is the machine only pressurises to 3 bar which is below the operating pressure so it may not show a leak whereas if done properly it will. I install domestic AC systems and on those they are pressure tested to 40 bar and ideally left for a minimum of 2 hours. So although I don't have any R134A, I do have the kit for pressure testing. The other halves Merc was losing gas after 3 or 4 months so I pressure tested it at 10 bar and it had to be left overnight before the pressure drop was noticeable. It's a shame you aren't a bit closer to me, I have two friends (both former P38 owners as it happens) that are mobile AC engineers. On a very small leak like you have there's three options. Replace anything that hasn't already been replaced, get it gassed by Kwik Fit (or ATS who often have cheap deals through Groupon) every year or use a leak sealer. The latter will keep it running for a couple of years at least on a small leak (the missus's Merc has been working for almost 3 since we put some in) and Halfords do a small can for around £20. The problem there is that it needs to be added during the regas process. The system is half filled, the can attached and some of the gas is allowed into the can, shake it about a bit to mix the two liquids, then let the mix into the system before continuing with putting the gas in. So not an option if someone is using the programmable machine as they won't be able to interrupt the process.
Ahh that makes sense. So ideally you need 8mm long M6 bolts (or longer ones and cut them down).