malcolmdc

During a break in the weather I did a quick coil change to the (easy) top coil, this sorted the stutter for about a week but now its come back! In my parking space with no shelter, anyone know the easiest way to get at the (awkward) bottom coil pack, pending a full dismantle job to do the leads later?

Japparts caliper fitted with new pads each side, good as gold, job done. Now for the rears . . .

Thanks, Malc, but tried 3 tanks of max, but once motor is warmed up the little hiccup returns! Have got a set of leads and coils waiting to be fitted, and may do the distrib caps and rotors at the same time. Cheers.

It seems that at a certain age, these old LS400s start creaking like their owners! Now I have a tiny misfire on part-throttle pickup at about 40mph. Just an annoying hesitation, which vanishes if I put my foot down a bit more. I have replaced the plugs (correct iridium) and the garage diagnostics showed no codes at all! Seems more prevalent once the motor has properly warmed up on a significant journey. Any ideas anyone or experienced it too?

Have moved on, having identified the correct caliper needed (couldn't find a rebuild company or correctly i/d a refurb kit, but piston is seized anyway!). JapParts have come up with a guaranteed used one so going with that. I've successfully used them before for a used rear caliper 4 years ago, so should be ok, have found them very helpful with photographic identification of parts, casting Mark's, etc.

Help! My venerable 1991 LS400 Mk1 has got a seized front right caliper piston, and calipers seem to be Unobtanium. It also seems that LS400s of that vintage MAY have had either 275mm discs or 296mm. My question is, are the calipers common to both disc sizes, or are they distinctly different? I have found a remanufactured caliper quoting disc size 296 but none so far mentioning 275, which is what I have. Has anyone know a source of supply, or one kicking around to sell?

Replaced the LS400 (1991) discs front and rear with drilled/grooved models from USA. Prices very good. Search Fleabay for plenty of parts dealers over there, carefully measure your old discs and cross check dimensions before you order (even my Mk1 had 2 variations I found, despite matching chassis numbers!). The heavy old beast now STOPS . . . .

Just had the front upper balljoint/wishbones replaced on my Mk 1, but had to get these from Kansas, USA, cos obsolete at Lexus UK and everyone else I tried first! They are known (apparently) for not lasting well. My Garage Man (who also has a venerable Mk 2) warned me of rear radius arm box sections which rust and break from inside, and were apparently a recall item in the dim and distant past! Well done for flagging all these potential disasters, Malc.

Fifth Gear on TV - Jason Plato did some comparative tests on "cheap" things to improve performance on an old-ish Golf VR6. He started by putting a bottle of fuel cleaning additive in a tankful of gas, after running it for a week it gave him 6 bhp on the dyno, which was more than he subsequently got from oil/filter change, then plug/leads change. I do this on my LS400 Mk 1 about every 8/10 tankfuls and it seems to wake the motor up a bit each time. Can't do any harm, anyway . . . . .

Thanks John! I hadn't got round to that because I imagined (poor old bugger!) that it wouldn't be quite so openly described! Happy Days . . .

Have had this identical problem twice on my Mk1 LS400, and on both occasions it was the rear brake caliper seizing, (first the right, and 12 months later the left) this made everything very hot, and alarming vibration fading when allowed to cool down. Calipers CAN be rebuilt if you, or your repairer, can get the overhaul kits (USA probably - watch the cylinder internal diameter!), but I replaced them on both occasions and complete cure resulted. I can tell you its a bit of a pain getting new calipers cos there are different shape variations, but ebay came up with some from Germany, about 120 quid each time. Lots of photos ensured no mistakes.

Following the failure of my 1991 LS400 Mk1 rev counter (I've had it all to bits - its busted), I am thinking the only solution is to buy a used binnacle unit, and swop 'em over. BUT, as my motor is of unusually low mileage (50,000 now genuine) the question of the used odometer showing probably100k-plus mileage will be an irritation at the very least. I know that "clocking" is naughty, and openly cannot be arranged, but it must have been necessary to replace these binnacles back in the day - how did the trade preserve continuity of mileage then? Is the little mechanical odometer unit detachable in any way to re-fix it to the replacement binnacle unit? Has anyone ANY knowledge of this which may be helpful?

Hi Guys (Especially Malc!) - Found this post on the USA L.O.C. website, and I intend to try this when the weather settles down (my LS400 lives outside!). It was suggested as a cure when the u/s revcounter needle sits BELOW the zero mark, but may work in other circumstances. 1. Remove instrument cluster (and I'm hoping I can leave it connected!) 2. Remove front transparent cover. 3. Gently grasp r/c needle and pull out till a 'pop' is heard, or felt. 4. Rotate needle CLOCKWISE till similar 'pop' is felt, then gently release needle. 5. Push needle ANTICLOCKWISE to align with Zero mark. 6. Test by pushing needle to, say, 3000, and release, and it should return to zero - If it does, HAPPY DAYS, it should now work after reassembly. U.S.A. site feedback from at least one guy indicates this idea is a go-er, but then I guess we have nothing to lose by trying it.

As a postscript to the above - nearly 2 years on they have proved to be absolutely fine, cross-drilling better than standard fit. bearing that in mind, I have just fitted grooved and crossdrilled front discs and they are a considerable improvement on the old ones. The discs and pads were about 150 quid from the U.S.of A. via fleabay. And the old girl sailed through yet another MoT with no hint of problems.

Have been using Tesco Momentum for long enough to let the old girl (LS400 Mk1) get used to it, and she is very happy with the performance over the "cooking" grade. By the way, a week ago I filled up at ASDA in Brighton Marina, being a bit short for the journey home, also out of curiosity, as it was dirt cheap (relatively!) at only £1.10(.9) litre. What the grade was I couldn't see - they only sell the one - but the car runs surprisingly well on it! Not too many ASDA fuel stations where I live but if anyone has one near them, there's money to be saved!

Lexus have never improved (matched?) on the LS400 - my 1991 Mk1 has this week passed its MoT again with NO advisories, and a comment from the tester that he'd not heard a sweeter engine in anything he'd tested recently! I think it may outlast me . . .

Interesting observation for those who may only change their LS400 air filter once a year, or have forgotten about it for longer! I have just changed mine after only about 10 months and the old one looked like someone had swept a chimney with it! The Old Girl audibly heaved a sigh of relief and now goes better. . . . .

I'm now running my LS400 Mk1 on Tesco Momentum, which is considerably cheaper than the other makes of premium fuel (typically only 5p dearer than their "cooking" brew) and it is definitely smoother and peppier at lower revs, ie most of the time. Reckon the mpg improved a little too. I did do an ECU reset before changing to help it learn the different octane rating.

My LS400 Mk 1 suffered from random alarms, but I WAS getting a "door-open" indicator light in the dash. Turned out to be a faulty boot-lid switch which wasn't switching the boot courtesy light out, thus indicating boot open = alarm goes off! Its like the fridge - who knows if the light REALLY goes out . . . . .

This may be a clue to my own, similar, problem (see previous posts) on my low-mileage Mk I. I will investigate for said wire - if its intact, what is the next step?

I am clearly only a beginner with the THUMP technique - One good thump and its finished it off completely, with needle now right at the bottom, motionless! Are rev counters repairable, or am I advised to get a salvage replacement, or is an Auto-electrician likely to be any help? Steve, you mention a "procedure", is it a DIY or a money job? A dead rc is not the end of the world but the rest of the beast is so good its a bit of a shame . . .

I picked up on the middle paragraph here - my 1991 LS400 rev counter is reluctant to register; nothing on tickover, wavers up to about 1500 only during driving! Haven't found anyone with a suggestion - was it a known problem?

Yes, They have this "one-make parking" idea for 20 year model lines, and only charge a fiver for on-site parking for the day including driver and passenger admission. Good value considering normal price is about 15 quid each!

Thanks, Malc, I am kinda thinking the same way - I ain't ever going to over-rev it, my courage goes well before then! I notice you're Kent-based, you going to do one-make parking at Bromley motoring pageant? I was on my own there last year, could do with a few more LS400's to show off.

On my lovely low-mileage LS400 Mk1, I wonder if (is this possible?) my rev-counter reads, or is calibrated, low. I know a big V8 has all the torque in the world for around-town-local driving, but it seems to read on or around 700-1000 rpm all the time out to about 50 mph, unless sport/2nd gear hold is used for hooligan behaviour. Then I see up to 3000-ish, but the revcounter/road speed doesn't seem right. Tickover is indicated 50 (!) rpm, smooth as a nut, and the car generally drives as normal. Top overdrive at 80 indicates about 1800rpm. I'm baffled, but should I be concerned? Ave mpg 22.6 so about normal too.