4000 rpm showing at idle

[Mxer125]

My Elan is running

Yay, really happy this evening after 10+years..

So I've a few things still to sort obvious ones being hazards don't work including indicators etc..

But what's really bugging me is the rev counter it goes from 0 to 4000rpm on idle??. Now I've just replaced the fuel pump and cut the little coils off, I'm wondering if these where suppression noise filters to protect sensitive electronics like the tachometer even tho they are far apart from each other???...'m unsure if it did this before as I never knew the car when it was running?.So Could of always been like this?


So yeah? Haven't a clue on where to start on this one.just letting you know electrically I've replaced the fuel pump, it may have an impact who knows

Rpm jumps straight to 4000rpm on idle,anyone ever experienced this and solved the issue Any help or clue's or stabs in the dark would be greatly appreciated..

[dapinky]

Electrics are NOT my area of expertise, so I can't really help with the revs issue.... but can I confirm that the car idles at 4000RPM, or it idles normally, but the gauge shows 4000RPM?

As for the hazard lights, I can offer some help there - the switch is a multi-pin thing with something like a dozen contacts on the back, and if there is any loss of connection on one or more pins the whole lot stops (including the indicators which are wired through the H switch).

It *may* be a faulty switch, but far more likely to just need a bit of a clean/reseat of the contacts (and moving parts in the switch).

Simply operating the switch a number of times may get it fired into life, or removal and replacement (after a squirt of contact cleaner if you have some). An issue I have found is that the switch sits in a plastic socket which is held in place by 2 small plastic tabs. Because there are lots of contact pins, it takes quite a firm push to seat the switch, and the plastic tabs break. When that happens, the switch gets pushed backwards, but the socket also moves, so the pins do not engage. You need to get your hand behind the switch to hold the socket whilst seating the switch itself. There is no simple access, but it is possible to get a hand in from the passenger footwell, the radio aperture or the ashtray (if you remove the housing which is glued to the fascia).

[rob/d]

I had the same thing for a minute , the negative terminal on the battery worked loose, rev counter went nuts .
Check your grounds are good ?
That stupid hazard switch is a pain .
I ritually switch it on and off as many times as i can stand every couple of months .
It comes good after a few clicks , and the indicators work properly again .

[Mxer125]

Hi Dave..
Yes car idle's normally (say 900rpm). but tachometer shows 4000rpm (jumps straight to it from 0)..


Regarding the hazards & indicators:

Ok I've managed to get the switch in my hand and clean all contacts and made sure all pins are located. I've exercised the switch plenty of times but still I have nothing, I've also checked fuse 11 which is fine.. any other ideas or things to check?..

[Tuga2112]

the idle reading comes directly from the ingition module to the instrument cluster, if the revs are normal. i would check if theres any loose wires at the back of the cluster that may be shorting the PCB or something around that area.

[Simon_P]

Either operate the switch 1000 cycles or take it apart and clean the contacts.
There's a how to somewhere. See Switchcraft in the wiki.

[Mxer125]

Still nothing on the hazards or indicators. The switch itself looks brand new now I've cleaned it.. i might see if it comes apart but before I do..

I have no power to fuse 5 and 6 ?

Apparently RH sidelight LH sidelight

Could this be something?

[Mxer125]

Ok I've disassembled the hazard switch and completely cleaned all connectors to shiny cooper and still absolutely nothing..

I'd of thought I'd at least get something..

I have both bulbs working on the hazard switch so I'm guessing 12v is present so I'm completely lost ...

[Mxer125]

No worries I've sorted it..

For those who may need direction if no hazards or indicators

I cleaned up the hazard internal and external switch.. I removed and cleaned the flasher relay under the steering wheel (I think this was my issue) as the contacts had got stuck where the coil opens and closes the actuator..

Anyways very happy I now have nice functioning indicators and a proper hazard switch

[rob/d]

Yay !

[Tuga2112]

what about the RPM reading ?

[Mxer125]

what about the RPM reading ?

No not yet. This one is over my head....

I've removed and jiggled all the connections at the back of the instrument cluster but nothing..

A friend of mine actually suggested I remove the needle and set it back down to 900rpm at idle but I'm not convinced as it jumps straight to 4000rpm?.. so something or some value is too much!! I don't think it's a mechanical issue more an electronic value issue (but where?)..

[Tuga2112]

what about the RPM reading ?

No not yet. This one is over my head....

I've removed and jiggled all the connections at the back of the instrument cluster but nothing..

A friend of mine actually suggested I remove the needle and set it back down to 900rpm at idle but I'm not convinced as it jumps straight to 4000rpm?.. so something or some value is too much!! I don't think it's a mechanical issue more an electronic value issue (but where?)..

As mentioned originally.
Rpm reading is driven by a electrical wire that goes from the ignition module to the back of the cluster. No mechanical parts with exception of the internals of the cluster

[Mxer125]

Mmm yeah like I said I'm totally lost with this one?. There is a tech meter on eBay ATM that would probably be my next stage?.

[Tuga2112]

have you checked if theres any loose wires (exposed) behind the cluster ? if you remove the binnacle cover you can lean over and take a better look from outside the car through the glass. its awkawrd to move things baout ther,e i usually have needle nose plaiers on the left hand or just take the roof off and stand inside the car.

[Mxer125]

Yeah, thanks Tuga.. I've removed the multi plugs on both Speedo and techometer . Connections look clean and healthy?.

[Tuga2112]

im refering to other wires in the area behind the cluster. if theres anything loose there that is exposed

[Mxer125]

Cover is still off ATM. So I'll have a thorough check, cheers Tuga..