Ok, I don’t seem to have any significant vacuum leaks I don’t think. Some smoke was escaping around the throttle spindle but I would assume that would be corrected by the base idle and idle CO adjustments. Checked for a dead cylinder with the laser thermometer and found the odd bank to be significantly cooler than the even cylinders, but no one cold cylinder. Assuming that I have a rich condition on the odd bank leading to cooler EGTs.

Next moved on to checking for codes with RoverGauge. Both lambda sensor codes were present. Both lambda short term trims were 100% rich but I think that’s a response to the codes. Cleared the codes and started on the Electronic Troubleshooting Manual procedures for those codes. Found that the earth wire for the odd bank lambda heater had a break. Fixed that and tried running again.

At idle the odd bank lambda is at 100% rich short term trim and the even between 30-70% rich. At steady 3000RPM this changed to about 50% rich on the odd bank and about 30% lean on the even bank. I think this is a lot more trim than I would expect in all conditions? Idle is still quite rough, odd bank still about 20C cooler than the even bank across the board. Also felt like there was a steady miss at 3000RPM that wasn’t there yesterday. Any suggestions?

Rich

I think @classic kev knows the v8 well

After a week of attempts to diagnose the emissions issue, I've ended up doing the following...

Found and repaired a break in the earth to the odd (left) bank lambda sensor
Fitted a full ignition upgrade kit from RPI (Amplifier, Coil, Leads, Cap, Rotor and Plugs)
Took it for a 30 mile round trip run to a friend's garage in order to
Set the ignition timing
Fitted a pair of new lambda sensors

Other than the engine running issues, I did spend some time fixing other things too...

Replaced the viscous coupling in the centre differential with a good used one, changed the transfer box oil and refitted the front prop shaft
Replaced the coolant temperature sensor for the dashboard gauge so I don't have to have the rovergauge laptop on all the time for coolant temperature

I think there's still something/some things wrong, but it's definitely running better, and well enough that it has an MOT certificate. Personally I'm not entirely confident that it really passed the emissions test but I have a pass certificate so I'm happy. If I can't find anything else wrong with it then I'll probably have a friend help me make a new downpipe with new cats, but I'll try putting a bit of fuel through it first and see if it gets any smoother.

Teething troubles that need fixing soonest are...

Bonnet catch is tempramental
Fuel gauge inoperative
Bad driveline noise somewhere - maybe rear diff?
Air suspension still leaking down over night
Air suspension still not working off computer

Most important thing to do now though I think is get driving it and enjoy it after all that time as a driveway ornament.

Soo excited.

Richard

Great to hear you’ve got it tested!

Hi All,

Nearly two weeks of motoring down. Only one failure to proceed and four days on the driveway unavailable for use.



Failure to proceed was a dicky connection on the fuel pump which I actually remember first finding when I put the tank back in. Seems it hasn't fixed itself. I've cleaned all the connections, fiddled with them, removed a redundant spade connector which I thought was the cause of the loose connection. The next morning I discovered that it wasn't when the car stopped on me a mile from home on my way out. Only takes a few minutes to get the carpet out and the panel out of the floor when you've had some practice fortunately and then I was back on my way.

Four days on the driveway was due to investigations into the driveline noise. The symptom was a whining whenever not under acceleration load and a bad vibration/rumbling when under heavy load such as maintaining speed up hill on the motorway. I was advised to recheck the u-joints in the prop. On checking them I discovered 2mm lateral play in the rear diff pinion flange. That will probably be it then. Needed the car last Tuesday so whilled the diff out about 1500 on Monday, then did the same to the Disco, only to remember that the Disco has a 3 bolt flange. Not to worry, I'll swap the flanges. Not a chance that spigot was coming out of the Disco flange to give me access to the nut. Two days later and one sheared off M8 bolt in the spigot I drilled and tapped it to M10 and managed to pull it with an 8.8 grade M10 bolt the same day that a new used diff arrived.



The new used one turned out to be fitted with a 3 bolt flange anyway so that can go in the Disco. It was only at this point that I discovered that the old diff was actually probably not my car's original, and someone had been here before which explained the failure. 4 bolt flanges require a spacer behind them - 3 bolt do not. Doesn't take insider information or a genius to work this out since the pinion wobbles about even when the bolt/nut it tightened up. See below side-by-side of two flanges showing difference in length of the bit that goes into the diff.



Actually whoever was here before worked out there should be a spacer, but rather than getting one they appear to have gnawed off part of the 3 bolt flange I assume they removed from what I assume was a used diff, and didn't do so to the right length or even square so their makeshift spacer didn't actually have any effect. Look at that for a nice clean cut.



I then proceeded to whip the spacer from behind the flange on the front diff of the Disco, so that's now got bits out of both diffs but at least the Range Rover was back on the road, three days too late to go to work. Oh well. Popped new U-joints in the shaft and ran it through the parts wash tank while it was out...



I spent some more time last week back under the boot floor again having another go at the loose wiring which I'm still not sure is fixed, and also the fuel gauge sensor wiring (which is in the same connector). I had the sender/pump unit out. I've cleaned all the contacts up, squeezed the female side to get a better contact, fiddled about a bit and eventually the gauge is sort of working. The resistance between the sensor and all the connections is never quite low enough to read full but at least I know when it says empty it means empty. Shame it says it so often!

I've also fixed the bonnet catch by moving the spring to another hole in the slam panel to make it pull harder. No trouble since that.



That only leaves the air suspension off my list then? Well not quite. The engine really doesn't like idling. It varies between a little lumpy and about to stall any moment, but never actually stalls. It's not a hunting issue but a stumble. I'm guessing at the moment either I have a fuel pressure issue or an air leak, but since it seems to run great off idle I'm erring towards air leak. Cant find one though. Could it be the inlet manifold gasket leaking on the bottom side into the crank case maybe? Also have a horrible whine on the stereo, and I'm getting samples of headlining material sent over too so that I can concentrate on the important issues rather than the engine or the suspension.

450 miles or so soo far, average 17.4MPG.

Rich

dieseldog69 said:

Welcome back

I like to keep one of those little bottles handy with the regulator, not because they looks pretty but because I inevitably forget to get a fresh bottle and run out mid weld with a tiny amount to finish on a Sunday afternoon lol

Last time I had the little bottle on I had to put a hot water bottle round the regulator to stop it freezing lol

View attachment 196014

View attachment 196012

Great to see you're still cracking away at her.

Keep going.....

Click to expand...

Your regulator shouldn't be freezing up like that. Have you got the gas flow too high or is it because you have the cylinder horizontal? You could be allowing liquid to come out instead of gas.

Well. Not been on here much in the last month really. Range Rover has been the sole vehicle in the house for most of December as my wife's car was written off. It's not had the care I'd have liked but it's kept going. Desperately need to get the alternator swapped over, deal with the swivel leak and find the main beam telltale lamp that I dropped behind the dash somewhere. Other than that the air suspension still isn't working on the computer and it still had a stumble at idle but it's been as good as gold. Fuel economy isn't even as bad as I had been expecting!



Rich

Hi All,

Been putting it off due to the photo upload issue but I've discovered a work around today by pasting into the editor rather than using the 'upload a file' button.

Soon after my last message it got a 300 mile service. Oil, Filter etc and a little more. I stripped the entire inlet system incase my vacuum leak was from the gasket between intake manifold and cylinder head. Replaced that, the rover cover gaskets, the gasket for the idle control valve housing and the gasket for the throttle position sensor. Was pleased how clean it looks in there...



At the same time I swapped the wrong alternator/bracket/crank pulley etc for a set actually intended for a car with EAS. Now I can tighten the alternator bely properly and it doesn't hit the shock absorber or squeal all the time! Brilliant. Shame the used alternator has a whine of it's own but it's working.

While I was reassembling I managed to cut a couple of the o-rings for the injectors so I had to steal Kirsty's vaseline and replace them all. Not sure a wood screw is the recommended way to remove the filter baskets from the fuel rail end of them, but it does work.





None of this work made much difference to the running issue to be honest. While I was at it I've either caused or found a pin hole in the riser on the steel pipes for the heater circuit. This is apparently on back order annoyingly but I've managed to patch it with epoxy for now and will have to keep a close eye on the coolant level until the pipe becomes available again.

Next up I moved on to making my front doors match. This is how the passengers side was...



Notice the chopped up bit where a larger speaker has once been fitted in the corner. Totally unnecessary for the speakers that were in the car by the time it came to me and causing cracks in the frame. Made a patch...



Welded and ground down...



Much better. Slapped primer over it all, whacked the basket in for my woofer, hacked some of the hard foam off the back of the door card to clear it and popped it all together again. My original speaker covers were all cracked and tatty looking so I decided to try the covers that came with the speakers I was fitting. They looked totally halfords with the grills that came with them and in black so I painted them brown and used some speaker cloth instead. Better but I'm still not sold. Had to switch the mid-range back to the original cover anyway as this fouls the end of the dash when the door is closed!



Related to the radio I also still have annoying interference from the alternator coming through the speakers. It was a little more recent than the door card work but I have made an attempt to fix this. All I succeeded in was to short the amp trigger output on my head unit so now I have no sound at all but at least no interference I suppose. I'll have to send the head unit away in the hope someone can fix the issue else find another.

Later in January I tried to do some more work on getting to the bottom of the suspension troubles. I replaced some diodes in the wiring loom under the driver's seat and carpet...



Only difference made was that the warning lights work properly now on all three switches but the computer still won't talk to my laptop.

Still battling with the rough idle I got the smoke tester out at some point in February and ended up replacing the rubber seals on the throttle shaft. There definitely was a leak there which there definitely isn't now, but it's not made enough difference to say the issue is gone - it might be slightly better or I might just think it is.

Lastly over the past couple of weeks I've done a little more. Checking to see if there was an exhaust restriction I found this lot in the silencer which explains why it was rattling! Might be an indication of why the emissions weren't great at the MoT test or could just have been destroyed since then because of the running issue.



Chopped the cats off the downpipes to have a look inside them and they're both completely empty so I welded them back on. I'll be making a new downpipe with new cats in stainless before the next MoT test, but there's no point doing that until I've sorted the running issue. I also replaced the gaskets on the even bank manifold at the same time to try to stop that ticking at the back of no.8 exhaust port. No such luck so I think I need a new manifold.

At the same time I replaced the pinion flange and seal on the rear diff to finally stop that leaking and replaced the pipes to the power steering reservoir as that was weeping too.

So basically over the past two months I've done a fair bit of work on the car but in the grand scheme of things it's not actually any better than it was. At least the alternator belt doesn't squeal any more.

Rich

So the discovery is tentatively up for sale. As much as I’d like to take the time to finish it, we’d like to buy a house, three cars on the driveway here is tight, and I don’t really have the motivation at the moment to take it apart. Ad here And on this forum

If the right buyer doesn’t come along I may yet carry on but at the moment I’m hoping to find someone a bit like me who wants an original clean discovery and will look after it and finish it off.

Range Rover is plodding along. I’m working on the air suspension bits at the moment.

Rich

Well the Discovery is now sold and has gone to a new home. New owner is on here and seems happy.

Last time I updated about the range rover I had done a whole load of work but not really fixed much. I’ve been plodding along again ever since, fixing some things, not fixing others and breaking a few more.

First up, the idle issue…

I got myself a fuel pressure tester kit and a compression tester kit. I was able to get a decent compression tester kit that I’m happy with, but the fuel pressure kits available in the UK seem to all be crap. Oh well. Example compression number - they were all ok ish with one being just out of spec but I did the test cold and the manual says to run the engine to temperature first.



The fuel pressure tester leaked like a sieve from every joint, so I couldn’t check if the pressure was bleeding off too fast but the running pressure was fine. Bottom line, I did some testing and discovered nothing other than Mityvac compression testers are good and Chinese fuel pressure testers are crap.

Without any good reason, I decided to try a filthy spare MAF sensor that was in the car when I bought it. To my surprise it pretty much fixed the issue completely. Glad I spent so much time trying other things first!

I spent some time tinkering with the air suspension system too. I blasted and welded up some frilly bits on the box for the valve block…



Then I squeezed a Viair compressor in. Did a similar mod on mom’s p38 years ago. Has similar rating electrically but pushes more volume of air and is rated for 100% duty cycle so won’t die if there’s a leak in the system. As the photo below from before I blasted the box shows, I’m going to need to do quite a bit more modification to be able to fit the lid again though…



The lid will have to be modified to clear the valve block due to my earlier installation of a p38 driver pack and the box itself will have to be extended at the compressor end to make space to mount that on its side since there isn’t enough clearance to the floor to move the lid up far enough for it to stand vertical as the standard one did. Haven’t got around to this and have been driving around with it bare metal and without lid for about three months now.

Next distraction was the near side rear door. It’s quite rotten. The window frame is almost rotten through at the rear end of the door to the point where it wobbles. The frame to the bottom section of the door is well ventilated at the bottom and a little near the latch too. LSE doors are predictably rare, mostly rotten and otherwise expensive. I have found one though which I need to collect. I’ve also acquired this rust free ish Discovery door to use for parts. Plan is to strip the new LSE door of its skin, make good the frame using the Disco one for repair sections before painting, refitting the skin and having the door painted body colour. So far this is all I’ve managed though. At least it looks like a good starting point. I think the hard bit will be removing the aluminium skin without damaging it.



Next up I got distracted again, prepping the Discovery for an MOT test for the new owner. Had to do a quick repair on the cill though…







Since the Disco went I’ve been fiddling with the air conditioning on the Range Rover now that it’s hot and all the air conditioning specialists are too busy. The car is just old enough to be R12 charged originally. I’ve decided to convert to R134A since it was empty anyway. I’ve used conversion valves off Amazon for this but I’m not sure yet if they’re any good. They were certainly cheap. I’ve also gone through and replaced every o ring with new viton/HNBR ones which should be more resistant to the oil used in R134A than the originals might have been. Finally I’ve fitted a new dryer unit which was the only new part I could get for the entire system. Hopefully I can get it charged without any leaks next week before our next holiday.

Speaking of which, I’ve also been using the Range Rover. It’s been back to Yorkshire and Cumbria so far this year, then Scotland last weekend and more planned. Managed this on the way to Scotland which shocked me…



Rally went only marginally better than last year - we managed three stages which was better than 1.5 last year but not quite the plan. Oh well, at least the scenery was good. Decided this but looked a bit deep for fording so waited for the ferry to Arran instead.



Sunset camping on Arran…



That’s all for now. More soon hopefully.

Richard