Classic cars forum & vehicle restoration.

[Ray White]

Further digging just shows that I need various (now presumably obsolete) diagnostic tools that I am unlikely to either find or - if I can find them - would be unreasonably expensive.

However, the local Land Rover specialist (who I mentioned earlier) may well have the means to correct the fault and clear the messages...but that again is unlikely to be a cheap option.

There are essentially two potential culprits. The first, a seized or "flipped" height sensor arm. This causes the sensor to send the computer an "out of range" message. If this happens the EAS system protects itself by closing down the air pump and puts the car down on its bump stops.

The second fault is likely to be a sticking solenoid in the valve block which has the same effect.

While I can fix either of these faults, I must bear in mind that the vast majority of P38s have ended up in the breakers yard and while mine may still be in reasonable condition, it is of little financial value.

The immediate problem for me is that I need the car and can't really wait for the specialist to fit me in. This means that I am likely to fit Shrader valves as a temporary measure.

I would feel happier about bypassing the electronics if I could remove the pipes from the valve block and not have to cut them...but I have tried and they are well stuck. Also; even if I get them out I am not entirely sure they will ever go back in and remain air tight. I would therefore have to cut the 6mm plastic pipes and fit the Shrader valves....

Decisions, decisions !!

[ukdave2002]

In my admittedly limited experience of diagnosing electronic faults on modern vehicles, the vast majority have turned out to be sensor or connector related. Neither usually requires sophisticated diagnostic equipment, a multimeter and the ability to back-probe connectors will often tell you a great deal. I actually prefer an analogue meter to a DVM for some sensor testing, as changes can be easier to see.

The biggest challenge is getting the right information: firstly, knowing the expected operating range of the sensor, and secondly, finding wiring diagrams and the physical locations of the sensors, modules and connectors. You can trace wiring looms manually, but it's a pain!

My basic diagnostic process is:
1. Is the sensor/module receiving the correct power and earth?
2. Does the sensor output change as expected and remain within its specified range?
3. Is there continuity between the sensor, connectors and relevant module?

All of this can be checked with little more than a decent multimeter and some basic back-probing.

Looking at the height sensor itself is essentially a rotary potentiometer supplied with a regulated 5V reference. As the suspension moves, the linkage rotates the potentiometer and the output voltage changes, it will have 3 pins, one will be ground (0V) one will be 5v and the 3rd pin between 0 and 5v dependent on the sensor position. I'd check the 3rd pin voltage at both the sensor itself and the module and see if it changes appropriately.

Re the solenoid, is it receiving a control signal from the module?

There is probably a load of safety protection that prevent the the suspension from changing height, open door for example, you should be able to back-probe the ECU connector to see if any of these conditions are false, they normally will ground the relevant pin on the ECU, but you need to check specifics, again all this can be done with a multimeter.

I'd imagine there will be a calibration process to account for manufacturing tolerances of both the mechanical and electronic components?

A cheap code reader is also useful for reading and clearing basic fault codes, although more manufacturer-specific faults may require a more capable diagnostic tool.

[Ray White]

Hi Dave. The main issue I have, apart from being pushed into getting the car up and running as quickly as possible - it couldn't have come at a worse time, is not having the necessary equipment to re set the computer to allow the pump to work; even if I did find the culprit.; i.e. a sensor or faulty air valve.


If my plug in kicker won't do it then someone with the specialist equipment will have to...and I don''t have the time to wait around for them.

This, and the expense, is probably why so many cars have been bodged. Quite a few frustrated owners have even resorted to fitting standard coil springs.

.

[ukdave2002]

Hi Ray, It is a bit of a coincidence that you have a suspension fault and also problems with the Kicker , I would be looking at the module that the kicker communicates with, establish that it has power and ground and continuity to the devices it chats too, including the kicker, it may well be something as simple as a poor connection.

[Ray White]

[Rootes75]

Did some more work on the Commer project yesterday.

Had trouble with the daily driver this week, the clutch went so has caused loads of hassle getting to and from work. But it's in the garage and I'm waiting for it to be done.

So this weekend being car-less, we have used the 47 Hillman. We even took it to football this morning, and then this afternoon we popped down the local pub and afterwards our youngest had a couple circuits driving round the large car parks. He's 15 and he handles the car lovely.
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Various Rootes Vehicles.

[Ray White]

[Ray White]

Although the P38 suspension is holding up well with the Shrader valves, having a dashboard warning and idiot lights still present is a nuisance. I am pretty sure the M.O.T. inspector will take a dim view of it too!


As a precaution, I have ordered some new ride height sensors. I opted to buy a full set because as time goes by, parts for this model are becoming harder to find...

I expect to soon be able to replace the rear sensors and - with the appropriate computer - and air lines reconnected to the valve block - clear all the hard faults, returning the EAS to full working condition; hopefully in time for the M.O.T.

There is, of course, the possibility that the fault is, coincidentally, elsewhere. Should this be the case a fault code will appear; the most likely place being the valve block.

I am not really expecting that.


.

[MikeEdwards]

The "modern" daily driver went in for an oil and filter change and pre-MOT checkover the other day, which revealed a damaged boot on a track rod end, two suspension bushes past their best, and a possible problem with one of the rear springs. Oh, and the headlamp level sensor has broken again. The car has had a bit of an annoying clonk for a while, and I was pleased to see / hear that after swapping the track rod end it's largely gone away. I spent longer setting the tracking than swapping the part, and now I've got a steering wheel slightly out of line, so when I do the bushes I'll have to move things across a bit then check it again next time the yard is empty.

It's not a terrible list for a car of it's age and mileage, but the bushes were done around 10k miles ago, and the track rod around 15k. As I'm in a position to change them myself, though, I do tend to put cheaper parts on.
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1976 Vauxhall HP Firenza, 1976 Vauxhall Sportshatch (x2), 1986 Audi coupe quattro, 2000 Audi TT

[Rootes75]

My Son and I have been to a few nice Commercial shows recently and it has got us both dreaming again about driving my 1950 Commer. We restored her over a 10 year period but had issues with the cooling system so back in 2019 she was put in the shed and there she has remained.

Well, on Sunday we charged a battery up, I bought a new coil, we fitted that, cleaned the plugs and points and checked the gaps then connected it all up and hand primed the fuel.

Within about 30 seconds of my Son pressing the starter button she fired into life, what a lovely sound and the look on his face was an absolute picture!! Our plan now is to spend some time inspecting the cooling system, flush it, refill it etc over the winter and check the electrics through too.

Our biggest issue is that she is tight back in the corner of the shed so access is extremely limited.
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Various Rootes Vehicles.

[Ray White]

I spent some time today working on the rear height sensors. I have begun by replacing the off side. The original sensors may or may not be working but they are clearly past their best as the plastic parts simply disintegrated leaving the two fixing bolts flopping around in their bracket. I used my Dremel with a cutting disc to remove them.

The new parts have come as a set of four (it was much cheaper to buy them like that) and fitting was a simple enough job. Tomorrow (weather permitting) I will do the other side.

When the rear sensors have been fitted, I intend to return the air bag lines to the valve block. By fitting 'T' pieces to them, I will be able to retain the Shrader valves which will allow me to inflate the system sufficient to get the car to the garage where the electronic system can be re set. When the EAS is working properly, I could dispense with the Shrader valves and T pieces and join the air lines with straight couplers.

If I wanted to fix the electrical problem at home I would need a computer with "Windows" ( I have Apple) and a "nanotech" computer which is used to clear "hard" faults such as the '35MPH MAX' warning message and other lights on the dashboard. With the car's compressor unlocked, the system should return to normal.

More importantly, I can be confident that the MOT tester will have little to complain about!

.

[alastairq]

Ooodly doodly....the other day, my disreputable, house-value-demolishing daily driver passed yet another MoT....That's a total of 9 in my ownership, over 81000 miles [total currently 178400]...

Although I cannot afford to replace it...with anything that won't have more undiscovered faults than currently....or can be purchased for less than 4 figures....the 'thing' does have a full, proper, good-nick chassis [to make a Land Rover Defender owner weep!!]!
Plus, it is rear wheel drive....[although it does have a 4wd capability, I rarely employ it...always managing to 'unstick' using 2wd alone] which does suit my old-school driver education [like biros, and logarithm tables!]

The driver's seat turns out to be just the right height for my backside to hit without my having to employ bodily origami...which ,I find, more & more, suits my aging frame.

Plus, I can take to grass verges, cross-ditches, etc with an element of impunity. {I tend to spend most of my present driving using back lanes , etc....rather than 'main roads', which I find are full of eedjits I can do without having to deal with.}

So, ''Dad's taxi'' survives to annoy other road users for yet another year.

Total cost to me....?45!!

I even resorted to stamping on my only {& old] can of WD40...as the 'pressure' had disappeared, and I could still hear some stuff left inside....I needed to spray my plastic headlight lens cover thingies with it, to 'clean' them and reduce the obvious starring and crazing that old plastic headlight lenses tend to equip themselves with after 25 years or more.

No way did I want to have to replace them for an MoT. I mean, they'd cost money!!

The two front tyres received yet another 'advisory' each....for the 2nd year running....
The inside edge had become 'run-off,' due to rubbish tracking! Even after the MoT spot had apparently 'corrected' it 3 years back!! {I had been going through front tyres quite appreciably beforehand]...Anyway, I couldn't take the thing back as their tracking machine had 'broken' and they weren't going to replace it [not at several thousands of pounds!]

So, I bit a bullet and bought a new [old stock] laser tacking tool for the price of the garage doing it [or, Kwikfit?]...and did teh tracking myself.
Quite a bit out, even the steering wheel wasn't 'centred'...so I did it all.
It wasn't a difficult job, just a tedious one, involving a lot of kneeling and crawling on my part....wich at my age, isn't pleasant.

Still, neither tyre has worn any more subsequently....and they've done nearly 15000 miles since!!!

At 40 quid each, I really would like to get my money's worth out of them.

Not in the slightest bit 'dangerous'.....at least, not if nobody else drives the thing!!

I did 'choose' wisely when I originally bought them...from Camskill.
Thanks to the EU and their tyre performance ratings, these 40 quid chinese ditch-finders [in others' hands, }, had a better wet weather grading than the most expensive Michelins of the same size.

I'm glad I didn't get all precious about things, and cough up another 100 quid per tyre!!!!

My front number plate attracted yet another year's 'advisory' too...It has deteriorated [the same, since I got the thing]...but isn't likely to be misread....

So I'm not going to fork out another 20 quid for a new number plate.....

All in all, the MoT-time is a trade off for me....pain, against cost.
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Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
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Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[alastairq]

post deleted
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Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
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Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[consul 57]

[quote="alastairq"]Ooodly doodly....the other day, my disreputable, house-value-demolishing daily driver passed yet another MoT....That's a total of 9 in my ownership, over 81000 miles [total currently 178400]...




what is it?

[alastairq]