MX83 speedo issues

[WA_TRD_83]

hopefully someone on the forums will know more about these cars than I do, and its a simple fix.
MX83 Cressida, with standard 7MGE and auto gearbox.

The speedo doesnt like to work first thing in the morning or after the car has been sitting for a little while.
Will normally take about 5mins of driving before the speedo will then magically come back to life and operate as normal as though things are all good

was a bit of a worry driving past the cops and their radar gun the other day and not knowing what speed I was doing

Can someone pin point what might be the issue? and how to fix it?

its probably a simple fix - but I haven't had the car long, and I've never had an intermittant issue like this one

cheers
Damo

[bungs]

Series 1 or series 2?

Series 1 has a cable driven speedo, it could be sticking when cold and as it warms up it unsticks itself.

Series 2 has an electronic driven speedo, could possibly have some loose connection somewhere and comes to life when its warm too.

The speed sensor is on the back of the gearbox near the tailshaft, have a poke around there and see what you can see. Maybe take it off and clean it up etc.

[WA_TRD_83]

Sorry... its a 1992 ... series 2 Grande - thus electronic speedo

I might have to jack it up and have a look underneath

[triptek]

Could be a dodgy speed sensor. I'v also seen 2 or 3 dash clusters fail. I'v got a spare speed sensor and dash cluster if you want to try them. Applied instruments in balcatta repaired a cluster for me about a year ago.

[WA_TRD_83]

the rest of the gauges in the dash work fine
is the speed sensor the bit that plugs into the gearbox?

[triptek]

the rest of the gauges in the dash work fine
is the speed sensor the bit that plugs into the gearbox?

Yer it's the one that screws onto the gearbox. The speedo is the only gauge i'v had fail on my cressys. All the others work fine.

[WA_TRD_83]

ok - I'll check it out. sounds like it might need replacing

cheers
Damo

[WA_TRD_83]

had a look underneath - everything is connected and looks pretty clean under there
I couldnt start pulling bits out cos I had nothing to replace them with.
Maybe I'll have to take a journey out to the triptek garage and get my speed sensor replaced and see if that helps ?!

Damo

[WA_TRD_83]

ok... still having issues as per the first post - but now takes more like 15mins for the speedo to kick into life.

and a new symptom cropped up recently, has happened a couple of times. I start the car, and the speedo just jumps to 80km/h and sits there. ?
at idle, or driving up the road, it doesn't move... just sits on 80...
weird.
then finally after 5mins or so, it will just drop to 0, and reset itself, then its all good and starts working normally again!

WTF?!

Someone please tell me where to start replacing / fixing things!

Damo

[JZA70R_92]

1st things first is replace speedo sensor happened similar in my old GA70 with digi dash!. give Triptek mark a bell he may have something!

[madmont]

Mine was working intermittently so I replaced the speedo . Worked ok after that

[cybersimon]

The speedo doesnt like to work first thing in the morning or after the car has been sitting for a little while.
Will normally take about 5mins of driving before the speedo will then magically come back to life and operate as normal as though things are all good

This exact same thing happens in my 91 grande. I haven't really worried about it to date because it generally only does it after the car has been sitting there unused for a few days, which is almost never.

Mine has had a 1J engine conversion, so its probably the speedo itself that plays up in these. Will be interested to see how you go in fixing this.

[triptek]

I'v got a spare speedo you can buy or borrow. Also have a dash cluster you can borrow.

[WA_TRD_83]

This exact same thing happens in my 91 grande. I haven't really worried about it to date because it generally only does it after the car has been sitting there unused for a few days, which is almost never.

Mine has had a 1J engine conversion, so its probably the speedo itself that plays up in these. Will be interested to see how you go in fixing this.

yeah, sounds about right... the less time mine has been sitting, the less time it takes to work again.
but since you have changed motor and gearbox, this would eliminate any errors there and point to the dash cluster which I assume as not been changed.

I might have to come visit you Mark and borrow that speedo cluster, swap it over and see if that fixes it. if it does, I'm more than happy to give you some $ for it...

now I just need to book in some time and pack a lunch to get all the way out to your place!! LoL

Damo

[Nilezy]

You will find that the capacitors have leaked on the PC board. This is what is causing the speedo to not work when cold and for the needle to jump to 80km/h or randomly move.

You will need to take the speedo board out of the car and clean the board and change the capacitors. If you don't do this soon, it will be damaged like mine is and you will have no speedo and no cruise control if it damages the chip on the board.

Triptek, you said you had a speedo you would sell?

Please PM me how much you want for the speedo.