New engine woes, please help..

Hey chaps,
I’m pretty much at the point of total confusion with my poor old lse rangie and wondered if anyone might know something i don’t or have missed..

Story so far- my engine suffered a cracked block, it was very long in the tooth anyhow so I found a good running replacement 4.2, did a pikey fix on it with new shells/ rings and a nice flowed set of big valve heads, viper cyclone cam. It didn’t run quite right with a slight miss, not so bad I was worried about driving it but just not quite right and the emissions were out with high co/ hc. I did 500 miles running it in then it shat itself, blew a hole in the rad and cracked block between cyls 2/4...
I’ve now had the block top hatted at Turner’s, all back together and it still runs the same. I’ve been over everything at least twice, substituted most of the common suspect parts to no avail.
The block is good, the cam is timed in with a piper vernier set, the heads were double checked during latest build, compression is good if a little all over the place sadly, injectors all flow the same but a tad more than Haynes say they should, I’ve just had the inlet off again today to see if it was an inlet leak but nothing obvious found. The misfire is worse from cold start and is an obvious miss, once warm it just sounds a tiny bit off but ain’t never going to pass an mot at 1.6 % co and raw petrol coming out the back.

As far as I can tell it’s cylinders 3&4 that have an issue- testing from cold start with a thermometer pointed right at the header exit from each exhaust flange (tubular headers) those two only produce approx the heat that the other six do until up to fully warm when it mostly evens out. 350+ deg c for six cyls, 150-200 deg c for suspect two.
Any ideas what temps I should expect at idle? I’m thinking the other pots are too hot and may be lean even though the plugs look confusing?

If I do a plug chop after 1 minute from cold 3&4 are proper black, the rest are blackish on one side of the insulator and white on tuther.

If anyone has something that might help, exhaust temps, possible reasons for cyls 3&4 to be off or want a misfiring Lse that Ive owend for 13 years but am about to torch please let me know!
Ta

Hey Rusty!
Off the top of my head I'm not sure but maybe a couple of things to check.
Try putting a vacuum gauge on it, this may be able to help identify if there is an inlet leak or any valve issues.
The cam is not standard (obviously) but have you adjusted ignition timing for the cam? I run a Kent H180, engine is happy at 10 degrees advance.
Misfires on 3 & 4.... I hope you won't think it stupid but have you checked the plug leads haven't been swapped over inadvertently? IIRC firing order is 1,8,4,3,6,5,7,2.

Good luck.

Hey Kev,
Long time away from Lz for me but it’s good to see you are still around!
Thanks for your suggestions.
I nearly drove myself potty thinking I might have been silly and got the firing order wrong too but it’s definately correct.
The coincidence of it being those two adjacent firing cylinders that are running differently is adding to my confusion if the Ill running like I’d wondered if it was too much overlap on the cam and it’s breathing back into the plenum on 4 before 3 fires but it has good compression, 170-180 psi across the board. I know other people have used this cam and it’s said to be designed for Hotwire.
I did consider the H180 cam but it would make my piston to valve clearances too tight .
I checked vacuum at the plenum and at warm idle it’s around 14 inches but I’ve no idea what our engines should be?
I tried a couple of colour tune plugs in 4&6 to see if I could see a difference in combustion but I couldn’t really tell and the vacuum dropped to 10 inches while running with them in.
Instructions for the cam say use up to 3 degrees extra ignition timing but it makes no difference to the misfire.
All along it’s felt like an inlet/ vacuum leak to me as from cold start it idles at 2k and takes longer than it should to slow and settle but I’ve been over everything countless times and found nothing. I wondered if having the heads skimmed and block decked when liners were done had thrown out the inlet manifold fit but I checked it using some plastiguage vertically across the ports and it squished very evenly..
I’ve used roverguage just to see what the ecu is receiving and doing and it shows the idle valve to be working but fully or very nearly closed at warm idle which is obviously wrong but I can’t fathom why.
All ecu side of things seems to be doing what it should so I’m stumped.
I’m going to pull apart and go through the ignition/ sparks wiring just in case as that’s been troublesome more than once and the remote amp blew a few weeks ago so I’m now using my last genuine lucas one..

Have you ever run a thermometer over the exhaust manifold? I’m interested to know what kind of temps a happy running v8 should be as getting in for 400 deg c at idle seems like a lot??

I know what you mean about vacuum. I tried looking and found no tangible information. Mine pulls about 15" Hg at idle with the H180 cam and 10 degrees of ignition advance, 4 branch headers and straight through cherry bomb silencers. The needle is nice and steady so all is good. The stable needle is probably one of the most important indicators with vacuum test/check.

So, as far as you know, the ignition leads are correct... misfire on 3 and 4... feels like inlet leak.I can only offer a couple of best guesses.
What about the dizzy cap and rotor arm. I had a niggling misfire and it was the cap and rotor. I also subsequently had a problem with corroded wires on the ignition amplifier so perhaps check the condition of the ends of the L.T. wires at amp and coil, if stiff/brittle cut off connectors, crimp on new and hopefully off you go!
I assume you are running cats - are the o2 sensors good? A bit of a hail mary here really because if o2 sensors, issues would be more noticeable when warm.
Inlet leak, possible but would affect more than just 2 pots. Check the condition of the throttle bypass pipe - the one from just in front of the throttle disc to the stepper, they split! (no.... really!)
Did you check the valve pre-load? Have you put shims in the pedestals? Vacuum test should show any valve problems.
Have you made any changes to the CO trim? Shouldn't really be a problem but just a thought but again this would not create a misfire on just 2 pots. CO trim should be set at a value of about 1.7v - 1.8v iirc for cats.
Have you tried a substitution test on the ignition leads?
Also, using Rover Gauge, you should be able to spot lean misfires and rich running because the lambda control with cats will try to alter the fuel trim and if there is a misfire, I believe the ECU would log a fault because the emissions would be out of range so maybe look for bank 1 and/or bank 2 misfire faults.

As for exhaust temperatures, I have never tried to measure them so can't help you there.
Let me know what you find.

Cheers

Thanks again Kev,
You are as always clued up on the ways of the v8!
I looked everywhere online and couldn’t find a single reference to expected or tested vacuum measurements! Frustrating when so many online sages say things like ‘check your vacuum’ or use a thermometer to see which pot/s are not firing..
Seems we have fairly similar specs then and only 1 inch vacuum difference as I also have a double s tubular headers and a two box (absorption only) straight through system, currently without cat as I’ve bought a new single high flow one and made it removeable so until the engine is running right it’s staying in its box! Not sure if 3.9 vs 4.2 and new compression makes much of a difference? The vacuum gauge sits dead steady.

I’ve been over all possible areas of vacuum leak more than once, I’ve even stripped the throttle spindle and fitted a new rubber seal behind the linkage as during a smoke test it wafted out of there. I’ve also replaced the gasket on the idle valve housing and the vacuum pipe to idle valve and the one from throttle to flame trap. Flame trap seems to waft out a slow steady stream of oil vapour so I assume that’s about right. I did run a 1mm drill through the rear engine breather inlet as it was completely blocked.

I can empathise with ignition problems having had to rewire the lt side twice over the years and fit a remote amp kit. I will go over all that at the weekend to be doubly sure.
The two pots running different is what’s really throwing me off as I’m 100% sure it’s not a head problem. Seats were all cnc cut for new valves, valve heights all spot on, all chambers have equal volume, compression is good, fuel pressure sits at 26psi running, only drops to 20 psi in 24 hours injectors all flowing the same on a 30 second flow test into bottles and seem to get equal signals with no dripping if left pressurised, I have tried and tested it’s usal afm and two s/h spares which all meter out the same and make no difference and as far as I can tell they are all getting good sparks.
One of the lambda sensors seemed to be misbehaving so I’ve fitted to new ltk ones and as far as I can tell are cycling correctly on roverguage although the ecu must think it’s doing just fine as it’s not throwing any codes or running out of trim as far as I can tell, must be the misfire confusing it?
Ive tried a spare correct 4.2 ecu, I’ve fitted a low mile very clean genuine lucas spare cap and set of new (rather rubbish modern) lucas leads in place of the low mile magnecore ones on the car. Ignition timing doesn’t wander at all with the strobe and pots 4&6 seemed to get a steady and constant spark while I was watching the colour tune plugs firing although I’m not sure it was just the engine not liking the colour tune plugs but pot6 (one of the hotter ones) seemed to begin not combusting after a minute or two of idling after which the flame would come and go while pot 4 (suspect rich one) ignited every time.
and there isn’t much else to an old engine...

Using my basic Gunson gas tester which is usually accurate to with .2% it’s reading 1.6% co and stinks of hc fumes no matter whether I run it on it’s correct 4.2 cat map, the Saudi 4.2 map or on a non cat 3.9 map even if I adjust the afm voltage down below 0.8v on non cat, that just seems to unsettle the idle more.
the preloads were checked and I had to use the thinnest shims but values varied from 20-65 thou which in all honesty would probably be just fine but I’ve bought a set of adjustable pushrods just because I like things to be just right that I’ll fit as soon as I can stomach going back into the valley..
if all pots were behaving the same it would be a lot easier to diagnose.
only other thing I can think of is camshaft but surely it isn’t possible for some of the lobes to be ground so out of sync that it would cause these problems yet still make good compression?
For the last 13 years the engine has needed nothing more than a new fuel pump, a few sets of plugs/ leads and some ignition wiring fixed, it’s makimg up for lost time now..

Blimey Rusty, you've had at it big style!!!

Didn't we do a troubleshoot a couple of years back for a mystery mid range misfire?? Maybe some of that could help?

From what you say, I can't see you've missed anything. I'm not sure/convinced it would be cam or valves based on the steady vacuum reading. I know what you mean about trying to find a steer on vacuum for the RV8, I think if you do a search I am probably the only one to have posted a reading. Most references say a good engine will pull 18"Hg at idle. The RV8 doesn't as far as I am aware. I don't remember ever vac testing before I did the cam swap but I do recall having the vacuum at 14" but after advancing the ignition a bit more, I reached 15", steady needle and crisp throttle response but mine is a 3.9, non-cat. The fact it is a 3.9 makes little difference as far as as I can tell. The 4.2 has a slightly different cam profile and lower compression but I believe the perceived wisdom is you can run a 4.2 with a 3.9 cam.

Anyway, none of that BS really helps your problem. I think I might be tempted to go back to the very basics.
The cam timing is good? Should be based on your vac test.
Ignition timing, cap, rotor, leads and plugs all good?
We know the efi is squirting fuel.
So we have (hopefully) all the basic bits - fuel, spark and bang!
Two pots not going BANG!
Why would a pot not go BANG! - 1: No fuel, 2: No air, 3 No Spark. But maybe also, no compression.
If no fuel check injectors.
If no air, check valves, throttle disc and spindle, air filter.
No spark - check ignition. Also, maybe put old plugs back in...? Sometimes a known working old component will show up a faulty new one!
Compression - wet and dry compression test when warm. (BTW I did a cold compression test and posted the result somewhere but I can't remember where!) but all pots were identical with just 1 exception that was only 5 or 10 psi up.
Do you notice the misfire when:
A: Cruising, steady throttle
B: Accelerating.
C: Coasting.
What shape is the distributor in? I'm grasping at straws a bit here but a worn dizzy can be a right nuisance.
The big problem here is deciding if a misfire is ignition or injection, can be tricky.

Silly me... forgot one other thing to check, what is the state of battery and alternator; weak batt and alty can cause misfires.

Hope that helps give you a steer.

Couldn't find a post with cold compression test readings. Guess I'm getting old!! Anyway, fwiw, I did write them down and saw the following results (COLD)

1: 160psi 2:165 3: 160psi 4: 160psi 5: 170psi 6: 160psi 7: 160psi 8: 160psi.

Warm compression figures for 3.9 are supposed to be 170psi - 180psi. There are no stated figures for the 4.2 which has a CR of 8.94:1 against the 3.9 which is 9.35:1 so I would guess, warm you should see say 165psi-175psi so cold maybe 155 - 160psi...ish.

Hope that data helps.

One other thought I had was whether or not you checked the trumpets in the ram housing. I'm not sure if loose trumpets could cause the problem you have but it is a thought.

I guess if all else fails you may have to consider taking it apart again and replace the head gaskets and the inlet manifold gasket. Not sure I have anything else, but maybe have a read through an old post of mine from when I did the cam swap, I'll dig up a link.

Cheers.

Thanks Kev,
I’ll reply in full later after I’ve been and sworn at the car some more.
The mystery misfire turned out to be the beginnings of the first cracked block shortly followed by hydraulic lock..
as the engine was an incorrect early 3.9 but l/r rebuilt unit that had done 100k I put the car under a bush til I found a good 4.2 to build to fit it and here we are..
the old block is now my coffee table and at least that works!.

I excitedly grabbed the rangie keys the moment I got home from work to check the fuel pressure as I wanted to be sure it’s correct and well, it isn’t quite..
I tested it at the weekend and I’d bet my right arm it sat at 35psi primed but not running but I forgot to check it running with and without the regulator vacuum pipe so just did that and the pressure gauge says 26 psi both primed (shouldn’t it be 35?) and running (about right?) and it only goes up by 2psi to 28 with the vacuum pipe disconnected which isn’t right I don’t think?
The car has a few year old britpart pump in her so I might just swap that for a good known used genuine one I have laying about to eliminate any possible ‘blue box’ problems..
also I pulled the oil filler plug out, just for a sniff and it had a fair bit of condensation inside it which made me pull the flame trap pipe off for a check as I’m now paranoid after all the block problems! must just be the damp weather but that had a coating of mayo inside the flame trap to plenum pipe..

To answer your awesome post-
I’m absolutely sure the cam timing is as right as it can be, I spent a whole evening ensuring it was dialled in where I wanted it using a piper vernier chain/ sprocket set.
The cam paperwork was a touch vague as it initially says the cam set to 108 datdc inlet lobe centre but then at the bottom of the page says ‘best power came when we set the cam at 104 datdc and advanced the ignition timing by 3 deg. I assume they meant it’s cast so that on standard sprockets it would be 108 datdc so I went bang in the middle and set inlet lobe centre at 106 datdc.

The compressions are a lot more varied than I would have liked from a fresh bottom end and vary from 160 to 180 stone cold with both pots that are currently running colder at 170 psi
I’m going to do a leakdown test on it when I manage to find my tester.. before I pull anything apart I want to know what if anything is leaking any compression.
It’s a new turner top hat block, old pistons and new rings, no reason for that not to be tip top. I almost wish I’d just refurbed the original heads and whacked a standard cam in but the unavailability of the 4.2 cams and my desire to fiddle saw the cam/ head spec I decided on.
Believe it or not I’m pretty good with engines.. I used to build race motorcycle engines both for myself and other people and have done plenty of cars but this is my first v8 which I’d hoped would be a sinch!.. how wrong I could be.

Another thing that has me hung up on those two pots being different to the rest isn’t necessarily current now as I’ve changed and tested so many parts but when I first put this engine together prior to the block and radiator splitting it still displayed similar issues but at that time pots 3&4 had nice light brown spark plugs and the other six were as white and lean as they could be. Now I have those two well over rich from cold and the others displaying blackbplug bases and half black/ half white insulators?.
Whatever is at the root of all this seems to have been there all along despite all new ignition parts, spare injectors and everything seeming to test out ok.

The misfire is most pronounced from stone cold when it sounds like a proper miss and a stab in the throttle from cold start produces a reaction akin to too much choke (while on open loop) once it warms for a minute or so (and I assume the lambdas try to help) its only noticeable at idle by ear as a slightly off beat but still has the emissions problems.
Once it’s warmed for a couple of minutes it drives fine and the idle begins to settle down to where it should be, river gauge isn’t showing it can’t contril the idle even though it seems to take too long to settle from cold to me and the idle valve is showing as too or completely closed.
only noticeable warm driving issue being on overrun- if I come off the gas at just under converter lockup speed the revs initially drop quickly as I’d expect them to but then after about 3 seconds they bounce back up by about 300rpm and stay like that feeling like it is ticking along too fast and pushing the car along more than it should. Acceleration is better than its ever been and it flies up to 5.5krpm and a good speed faster than an old rangie really should although once in lockup the acceleration feels lacklustre in comparison.


Other than checking the lt circuits and the rpm signal wire ( occasionally the Rev counter doesn’t work for the first 20 seconds or so which never happened before) I am sure the ignition side is good. Roverguage shows batt voltage at 13.8 running.
I have had misfire issues from the alternator before and have currently somewhat bodged an alternator from a serpentine engine in place ( it fits just fine if you hack off one of its mounting lugs..) while I get round to rebuilding the original one.

The trumpets are all good. I used the set that came with this block as my 3.9 ones used to lose two of them regularly and the rattle from them jumping about inside the plenum drove me potty.

Despite my affection for this car, equally my daughter who forbade me from selling it broken and buying a tvr instead I think I’d ebay it rather than take the engine out for a third time on the driveway and I think if I have to strip it down to a taking cam out condition in the car yet again I might actually cry then give up and fit a cheapo 3.9 cam & chain set, lap the valves on the old tired original heads and just pray it runs properly!.

I’m going to take stock, remind myself of the combustion principles yet again, find leak down tester, change fuel pump and take it from there.

I can’t think of anything else you can remotely do to help Kev, you’ve covered everything! I’ll keep you posted of any news and I thank you very much for your top class v8 knowledge

I know you know the mantra - don't quit!!
The only thought I had reading through your last post : Have you checked the vac advance on the dizzy and also the throttle pot.
If vac advance has a split diaphragm there is the opportunity for air leak but also, throttle behaviour can be affected. Same goes for iffy throttle pot, the ecu needs to see throttle position and rate of change to control fuelling and switch idle control on/off. Worth a look see.

Compression numbers look good but I am not sure about the variation. According to the book, if compression varies by more than 10%, piston rings or valves may be faulty. A wet/dry compression test could help establish if this is the case.

Fuel pressure - book says pump operates at 2.3 - 2.5 bar, so if my conversion is correct, that is about 32 - 35 psi so your numbers look a little low.

Was interested in what you said about cam timing. The Kent H180 also sits at 108 degrees after tdc and that is where mine is. The 4.2 cam spec was as follows:
Inlet opens: 28 deg. BTDC Exhaust opens 72 deg. BBDC
Inlet closes: 64 deg. ABDC Exhaust closes 20 deg. ATDC

Duration 272 deg. inlet and exhaust.
Valve peak: 108 deg. ATDC inlet and 116 deg. BTDC exhaust.

Standard ignition timing on the 4.2 is more advanced than for a 3.9. Standard is 8 deg. BTDC +/- 1 degree. So if you dial in an extra 3 degrees that gives you 11 deg.BTDC; I would probably go with an nice even 12 degrees of advance.

Based on this I would be inclined to re-time the ignition. Potentially I might also look at the cam/valve timing although if this was a big issue I would expect you would be having a bit more than just a mild misfire.

Oh, nearly forgot, https://www.landyzone.co.uk/land-rover/time-for-surgery.296902/ This is a thread I did when I changed my cam.
Hope that helps, let me know how it goes.

Thanks again Kev!
The most important mantra I try to work by in such situations is methodical testing and be sure of results before moving on and eventually the problem will be found. I seem to have gone round in circles this time and found nothing particularly wrong or a cure to the problem and even begun the less helpful chuck replacement parts at it approach..

I wish I had known the 4.2 cam spec before I’d chosen the cyclone! I looked everywhere for a spec to decide on cam profile against but couldn’t find it.. that said if I can get it running right i’ll be happy enough as the stock cam in the 3.9 used to annoy me with it totally running out of puff and changing gear at 4.5k regardless of how planted the loud pedal was. I nearly went for the Kent 180 but it has 0.2mm more lift than the cyclone and after the skimming of heads and block even with composite head gaskets I have just under 1.5mm piston to valve clearance, possibly also exaggerated by the larger valves which I was hoping would increase flow a little across a wider Rev range without needing big valve lift.

Anyhow..
Throttle pot seems to sweep very smoothly through its voltage range and shows at 5% at idle on roverguage. The afm shows I’m correct range on roverguage at idle but is just a tiny bit off, in fact all three I have here of varying ages are but only as they all overshoot at key on and take about 10 secs or so to settle at correct voltage, all seem to give expected signals and voltages at idle. M
dizzy vacuum unit is nearly new and good, I’ve checked zero advance vacuum available at idle as throttle disc was set when I yanked it out to change the little rubber seal.
The dizzy itself is the only 4.2 one I have and I’m sure it’s doing it’s job properly but I’m going to refurb a good 3.9 one tomorrow evening and chuck it on just to see if it makes any difference.

The fuel pressure is out of spec and I think it’s actually the pressure regulator sticking as It was definitely sat at 35 psi with pump running/ engine off last week when I flow tested the injectors but it’s a spare complete fuel rail that’s been sat in a box for years and only fitted last week and engine ran at idle in the drive for a few mins. The cars original fuel rail & components have been tested at least twice in the last few months and performed as they should with the only anomaly being the fuel flow over 30 secs was 10ml over the upper spec stated in the book on all 8 injectors.

I won’t worry about doing an oily compression test only as I think doing a leak down test to verify against the compression test I did last week might show more useful additional data.

My list for the weekend is-
cure fuel pressure issue

Change fuel pump/ filter and check fuel pipes & pressure regulator

Leak down test

Carefully inspect lt circuits, swap dizzy and set to 12deg
Run through all or as many ecu fuel and ignition checks as I can

Send a mouse up the exhaust to check it’s not blocked

Fit clean spark plugs and run car on non cat map and see what happens. If all systems pass their tests again then I guess I’ll have to pull it all apart and get down into its guts again for a very thorough measure.
I wish I’d been anal and measured more than just no.1 pot when I dialled in the cam and set all the valvetrain bits but I’d never have thought it necessary.
Still pinning my hopes on something less painful than a head/ cam problem for now.
I’ll keep you posted!
Thanks again
Rusty

Kev,
I meant to ask. How did you make your crank holding tool??
I’ve welded one up for my diesel van that I was very proud of and that is torqued at 350nm iirc.. but I hadn’t considered one for the v8. Sounds like a much better idea than crow bar in ring gear! Do tell

Crank holding tool was a bit of gorilla engineering. See attached photos. Bolts on to the two lower bolts on the timing cover and engages the big notch in the crank pulley damper. IMG 3 should give you an idea; this is the 4.2 out of my own LSE. I started stripping the car for rust repair and restoration but never did anything with it. Now my ankles/feet don't work properly so I can't stay on my feet for too long and have trouble bending down so I will probably end up selling it as a project.

Anyway, hope that helps ya! If you were closer I might have offered to give you a hand but it's a bit far from N.Wales. Good luck.

I have absolute respect for your ingenuity on the crank holding tool Kev! I’ll have to take a look and see if I can mark a tool up but sadly my welder is currently unavailable as it’s locked away in my workshop in what has become ex mrs no.2s garden..

Funny thing is one of the overriding reasons for wanting the car running properly is so that we can drive it to north wales! When we are allowed to of course.
We are often out camping etc and usually visit Caernarfon/ Anglesey and snowdonia a few times a year but for the last two years while the rangie has laid dormant we have had to cram ourselves, camping kit and dog into my mk1 Vw golf for all our adventures. Still, it’s 38 and never needed welding or any engine work. Wish I could say the for the rangie.

Sorry to hear about the ankles Kev! And the possible fate of your lse.
How much work does it need? I’m better at welding than misfire diagnosis..
Maybe we could organise a lz work party for the near future? I’m sure there’s a good few people here would return help that I’m sure you’ve given over the years especially if it was organised with some camping/ laning?!

Thanks Rusty! I came up with the idea after the usual swearing and cursing. What I used to do was jam a bar under the A/C compressor mount so that it held on the groove in the balancer then went at it but sometimes it would slip. I looked at it and thought about it for a while then came up with the Heath Robinson tool by welding some scraps of steel together. I could refine it but why bother - it works and that is all it needs to do! Glad it has given you a steer to make crank pulley easier to remove and then do up again.

Hahaha thought it funny you pop up here to N.Wales. Respect for doing in a MK1 Golf with all that stuff. Fix the Rangie, do it style & comfort; mind you, Golf cheaper on fuel and easier to park! If you're up this way give me a shout and swing by.

As for the ankles, well a bit embarrasing really. I fell through the barn roof and shattered my left leg and my right heel. I now have 2 K wires on the left knee, 2 longish plates and 15 screws on my lower left leg and then a plate and 8 screws in my right heel. As a result of all that, my feet and ankles don't work 100%. With COVID I haven't had physiotherapy for almost 12 months but I do what I can. My mobility is so much better, this time last year I was in a wheelchair. How much better it will get I don't know.

The LSE is a basket case. It needs both sills (complete), rear cross member, boot floor, lower tail gate, inner wings both sides and probably both footwells. It needs a lower tailgate. The doors are rusted out but I have spare doors to make repair panels out of! The heater box is in bits after the fan motor was found to be seized solid - I do have a replacement though. The air springs need sorting. I have put new Arnott bags on but haven't completely finished it. The bags will take air but leak. The compressor runs but the ecu has hard faults. I have lots of bits including a boot floor. On the plus side, the chassis is good. The engine did run and I still turn it by hand every now and again. I have promised myself to get on it time and again but life kind of gets in the way. I've done sills, cross member, body mounts, headlamp boxes etc before on my RRC so not really a problem but just getting round to it.... Ha! I've only had it in bits in the barn for 10 years!! I have concluded that perhaps I should move it on.

Hey Kev,
All I can say is OUCH! to the leg injuries. Sounds truly nasty and I seriously hope your mobility improves.

The lse sounds like so many..
When I bought mine 13 yrs ago on eBay the guy said it had a years mot and only one rust hole. What he didn’t say was that the hole extended the entire length and width of the car.. all the posts had to have new bottom thirds, cills etc.
I used it for a year, had a lot of fun laning then spent 9 months of nights and weekends rebuilding the body, at the time panels were hard to come by as yrm and the like were not yet around and the only supplier had gone bust. I found some front inner wings at an auto jumble, mhm had one disco footwell, i extended swb inner and outer cills, a britpart rear crossmember that after fitting found to have the tailgate hinges welded on too high, an ally boot floor from a scrapyard and had to make everything else all the body mounts, floor sections etc myself. The only job I left was the entire width of the bulkhead which lasted til last year and I did while the engine was out and it was a cow of a job .
Annoyingly when I lifted the boot carpet on Saturday to attack the fuel pump I noticed a big rust scab where the wiring comes in by the r/h rear light, poked it with my finger and had a two inch hole.. seems the steel I used has turned to mush, if I get it running it now needs more panels welding in again! Still, that was repaired 12/13 years ago which is as long as it lasted from the factory I guess.

As for finding the misfire..
The weather wasn’t very good so I didn’t get much done.
The spare pump I had has the wrong connector as it was from a soft dash and it fell apart when I tried to remove the bottom of it to check it prior to fitting.
I changed the fuel rail to one that I’m sure has a good regulator, tested the LT side which seems fine but I may swap back as it’s currently running a remote amp kit ibut didn’t get time to fit spare dissy.
The fuel pressure still only sits at 26psi with key on even with the return hose clamped off so I assume the pump is unwell. I tried to run it but I’ve made it worse and the idle is fluctuating wildly like an isv fault and was running even worse. I gave up at that point.. I’ll let you know what happens once I’ve swapped the pump etc.

I had a problem with a classic rangie missing slightly and it drove me mad I had replaced everything, even fitted new distributor and coil. It turned out to be the ignition lead, there was cross firing on the new leads i'd fitted when I replaced engine. I refiitted old leads from corner of garage and fixed it stone dead (also ensure leads are routed as per the manual as this can also cause cross firing. I think it was between 2 and 4 or 4 and 6.

V8s can be very funny about ignition parts.
Rotor arms with the metal strip riveted to the plastic are a no.
Pattern dizzy caps can be a problem. Had to fit one as a stopgap & immediately a misfire at higher revs when dry & even worse when wet. Difference between that & a good one was the good one had the 8 lead pickups covered in plastic apart from the bit that faces the rotor & the good one had a lot of cast in baffles

Is it a new cam?
I have had mystery missfires and spitting back through the carbs at high revs in the past and found that a couple of cam lobes had worn badly, preventing a couple of valves opening fully.

Thanks for your input guys.
The leads on the car now are new lucas ones, I admit I may not have routed them perfectly as I just threw them on to try them but I’ve checked In the dark and theres no cross sparking on them and the exact same misfire exists with either those or the Magnecor leads and different cap I took off.
Rotor arm is a good condition proper lucas one, dissy cap is a good genuine lucas one with all its plastic insulation bits around the contacts. I do have one of the crappy lucas ones that had bits of plastic missing that I’ve kept just as a desperate spare. Why do people make and sell rubbish?!

The cam is effectively new. It was new 800 miles ago when I built the engine up for the first time. It all seemed fine and looked ok when I took it out for the top hat liner job just obvious bedding in shininess on one side of each lobe but I never measured and timed every lobe when it went back in just timed it up to no.1 never thought I’d need to. Still, if I can’t find a fault anywhere else I’ll have no choice to pull it all apart and get the dial gauge out on all lobes just to be sure.
Whatever the problem is i’m thinking it’s been there ever since I put the engine together the first time and is still there after the top hat job and rebuild no.2 after 500 miles as those same two plugs were different colour to the other six back then.
I’ve swapped and changed all kinds of parts and it still has those two pots running differently the the others.
When I get a day off work and it’s not bloody raining I’ll get the pump changed and see what happens.