Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: al brown on 19 November 2010, 20:21:37

Title: Rev counter
Post by: al brown on 19 November 2010, 20:21:37
Where does the feed for the rev counter come from on a 3l v6 please, cant find it in the book of lies.

Cheers     Al
Title: Re: Rev counter
Post by: RobG on 19 November 2010, 20:49:08
The RPM signal is pin 43 on the ECU  and goes to pin 22 on the instrument panel, pin 30 on the ABS ecu and pin 6 of the MID
Wire colour is green IIRC

Title: Re: Rev counter
Post by: al brown on 19 November 2010, 20:52:53
Quote
The RPM signal is pin 43 on the ECU  and goes to pin 22 on the instrument panel, pin 30 on the ABS ecu and pin 6 of the MID
Wire colour is green IIRC


Cheers for the info but was actually after where the signal is generated from. My bad with a poorly worded question, I am a mechanical eng not an elect one.

Al
Title: Re: Rev counter
Post by: Kneepad on 19 November 2010, 21:00:25


That would be the crankshaft sensor then.
Title: Re: Rev counter
Post by: al brown on 19 November 2010, 21:03:21
Quote

That would be the crankshaft sensor then.

Was hoping that wouldnt be the answer, just replaced it under 5k ago. Rev counter is doing some strange stuff.


Al
Title: Re: Rev counter
Post by: Kevin Wood on 19 November 2010, 22:51:24
It's not directly from the crank sensor, but the crank sensor is used to determine engine RPM by the engine ECU. The engine ECU then generates a square wave signal (Pin 43, light green, as said :y) whose frequency is proportional to engine RPM.

I would expect a code 19 if the crank sensor is playing up.

Have you still got a misfire? just wondering if that's related?

kevin
Title: Re: Rev counter
Post by: al brown on 19 November 2010, 23:56:41
Quote
It's not directly from the crank sensor, but the crank sensor is used to determine engine RPM by the engine ECU. The engine ECU then generates a square wave signal (Pin 43, light green, as said :y) whose frequency is proportional to engine RPM.

I would expect a code 19 if the crank sensor is playing up.

Have you still got a misfire? just wondering if that's related?

kevin

Yep stiil missfiring some days, but today the rev counter was jumping around at a rate the engine clearly wasn't able to. So I was wondering if it is a common link to my problem, if there is a link between the rev counter and the plugs firing. Easy to say its the DIS if I have a misfire, but I am an aircraft tech and I know from experience that the easy answer isnt often the right one.

Al

Just to note, it was a gen vaux crank sensor I fitted (advice from here after my last non-gen one lasted 2 yrs)
Title: Re: Rev counter
Post by: Kevin Wood on 20 November 2010, 00:21:27
Hmm. Don't suppose you've got an HT lead braking down and causing interference to an adjacent circuit?  Might be worth running it in the dark to see if you can spot any flashes?

Kevin
Title: Re: Rev counter
Post by: al brown on 20 November 2010, 00:42:30
Never thought of that, will give it a try. Does feel like there is a different number of cylinders miss firing at different times