7 replies to this topic

[biggins]

Just done a bit of work on the car. It is a standard 1989 998cc. Replaced clutch hose and slave cylinder, tie bar bushes and a couple of spots of welding on the sills. Got back in it today and the rev counter is over reading, but it seems consitently over reading. At tick over it sits about 1500, 70 in forth reads about 5250 (used to sit about 3500 ish) and goes all the way 8000, which by ear would estimate should be 5000. The work I have done hasn't touched the coil. The earth strap is on securely and all other electrics work fine so I wouldn't have suspected that.

As I undertsand it the rev counter is connected directly to the coil so one of these things must be the problem or the wire in between. If it was the coil then I would have expected the running to be rough but it is very sweet. Could it be the rev counter?

Any help appreciated

Chris

[Jimmyarm]

Is there a switch on the Tacho that says 4,6,8 ? Make sure that is on four (although if it was on one of the other settings it would under read rather than over read).

Have you got a three clock dash ? If so the above wont apply, perhaps a problem with the voltage regulator.....not so hot on the std dash workings...were is DKlawson, he seems to know a fair bit about them !

[Dan]

Could be the points bouncing.

Could also be that the welding was done without electronic protection, the tacho is electronic and resistance welding can damage it if the correct protection isn't used.

[biggins]

Dan

I guess by asking this I am answering my own question, but, what protection measures would be normal for mig welding?

[Dan]

Either disconnect the battery and everything electronic or fit an isolator type thing accross the battery terminals I think. Not too sure, I don't tend to weld. I think mig is less dangerous than arc though.

Edited by Dan, 21 August 2006 - 02:18 PM.

[biggins]

Would this damage be permenant or could it be repaired/recalibrated? If so any ideas who could do it?

[Dan]

Speedy Cables could probably fix it but you need to find out for sure if it's damaged or not first. Someone will answer soon who knows more about welding than I do (and probably disagree completely ).

[JD8891]

When welding i just disconnected the neg lead from the batt and the car seemed to survive though the starter realy did play up but a quick opening and poke with a screwdriver from me grandad seemed to fix that.

JD