LS400 Mk1 Rev Counter

[malcolmdc]

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.

[Malc]

.....  does seem a little odd  ...  I don't remember my Mk1 ever being very much different to the usual revs indicated with my Mk2 and now my Mk3.

Philosophically:  If it's driving well and you're otherwise happy then I would take a view and leave the rev counter to re-adjust itself at some time in the future ( if ever )......  at age 25 I don't doubt little idiosyncracies are well deserved  ...  and expected

Malc

 

[malcolmdc]

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.

[Malc]

.....  I haven't been to that event since about 1985 summat ?  I used to live in Petts Wood, just up the road from there

It's a bit out of my way now

Does a 1995 Ls400 count for exhibiting then ?

Malc

[malcolmdc]

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!

[cleverdick]

I wonder if, at some point, somebody's seen fit to cake the indicator in conductive paint in order to restore full-length brightness?  (It's a trade secret, y'know!)  That would most certainly upset the dynamic balance of this precision instrument.

[malcolmdc]

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.

 

[Malc]

Thanks for that, my Mk1 is long gone BUT my Mk3, the current beauty, has a wobbly rev counter now ....  sometimes it works fine, other days it's haywire ............ my indy tells me that the unit needs replacing, the bouncyness is caused by old age affecting the solder ? joints in the gubbins of the unit and on a hot day it might work fine but on a cold day the bits inside ( whatever they are ) are a little too far apart to function as it might when 23 years younger.

You must know the feeling, not everything works as it might have in times past .  old age you know.

Replacement unit from Lexus is approaching some £3000 they tell me .... a Mk3 secondhand unit might work ok for now BUT for the future, well who knows.

I can live with it and it's idiosyncracies  

Malc