Skip to main content
Topic: Erratic Rev counter etc. (Read 198 times) previous topic - next topic

Erratic Rev counter etc.

1991 8v. A bit of a strange one after starting the car up after a few weeks, the Rev counter now fluctuates on idle and the temp light flashes. During this the MFA shows time but won’t scroll through the functions. Water levels ok and car heats up properly, gauge working, with fan coming in and car runs fine.

Taking it for a short run the display returns to normal, but on next start up the issue returns.

Checked main earths, cleaned coil contacts, sensor contacts, relays etc. Probably not a major issue but good to get it fixed.

Any ideas welcome.


Re: Erratic Rev counter etc.

Reply #1
Have you checked all the earths to the back of the head right side rear on rocker nut?, think there is about 3 or 4 of them?

Re: Erratic Rev counter etc.

Reply #2
Hi there. When you say head do you mean the instrument panel, which I guess would be a dash out job?

Re: Erratic Rev counter etc.

Reply #3
Head, as in on the top of the engine block. There are some cables that are earthed to the engine through the nuts that hold the cam cover on.

but FYI, if it was the instrument cluster, the black plastic instrument surround (switch panel) comes out quite easily. Pop out the switches and switch blanks and pop off the heater control nobs and you'll see screws. You'll need to pull out the stereo too.

The instrument cluster can then be removed from the front. Two screws, and reach round the back to disconnect the speedo and pull off the plug(s) at the bottom. 1 or 2 depending on year. And if you have the MFA (mpg read-out etc) you'll need to disconnect the vacuum pipe.

Dash wouldn't need to come out, but if for any reason you need the dash out, that is also fairly easy.

Re: Erratic Rev counter etc.

Reply #4
Got it. Was having a dim moment. Will check the earths when it stops raining here.

Thanks for the input.

Re: Erratic Rev counter etc.

Reply #5
Cleaned the earth on the cam cover and it seems to have done the trick.

Thanks for the info.