Rev counter

[mark]

Im running megajolt on my engine and its all up and running :D

The wiring is 99 percent complete but im having trouble with the rev counter, im using the standard sierra instrument panel. With the old set up the rev counter was driven from the coil but now thats gone how should i wire it?

There is an output on the megajolt but this does not work my particular rev counter for whatever reason, the megajolt instructions suggest that if this output doesnt work to try pin x (cant remember no. of top of head) from the edis 4 module. The pin they suggest is in the module itself but not the connector, before i drill through the connector has anyone got any ideas if this will even work.

If not i will get an auto electrician to have a look, its definately possible as spuds car has the same set up. I just cant see how its done on his as the loom is all taped up and fastened to his car :rolleyes:

[twinturbo]

which rev counter have you got?

The tach wire should be on your edis module


It's pin 2 for the TACH signal.

TT

[AshG]

yep my mjolt revoutput didnt work with my counter. i wired mine to pin 2 on the edis 4 and it now works perfectly. its the bright green wire that is not used for anything else.

[HandyAndy]

as you know i,m not into electrickery stuff :o

but i have a spare sierra binnicle AND a standalone rev counter if you want to try them , to make sure everything is working once you sort out the pin as per TT,s post above.

cheers
andy

[mark]

Its just the standard rev counter in the sierra cluster

Just been out and had a look at my edis and you are correct TT it is pin 2 that the instructions suggest using. The problem is that my edis connector doesnt have a wire coming out at this pin, its just solid plastic. The pin is actually there on the module just not the connector

This is why i want to know if anybody knows it will work before i let the drill loose on the connector :D

Also will the fact that the coil pack is a wasted spark make a difference

[mark]

as you know i,m not into electrickery stuff :o

but i have a spare sierra binnicle AND a standalone rev counter if you want to try them , to make sure everything is working once you sort out the pin as per TT,s post above.

cheers
andy

Cheers Ash/Andy

Sounds like i have the only edis connector in the country without the output for the rev counter! :D

I will try and modify the connector so i can try it and if that fails i may boorow your stuff just to eliminate a dodgy rev counter in my cluster, it did work when i stripped the car but its been stored for almost a year now.

[HandyAndy]

no prob Mark, i,ve also got the Edis 4 with connector set/clip that Deezee has sent to me that hasn,t found its way to my car yet, welcome to try that too ;)

cheers
andy

[twinturbo]

Place a thin wire in the plug side of the plug to make contact with the pin.

TT

[mark]

Place a thin wire in the plug side of the plug to make contact with the pin.

TT

Thanks will give it a try, will have to wait until tommorow now though as i havnt got my exhaust on at the moment so its sounds like an old war plane in my little quiet street :D

[spud69]

Hello Mark,

I've just checked on mine and it is on pin 2 of the EDIS unit, the rev counter works fine on there even though it's a wasted spark it is still giving the same amount of signals as the coil it's just that it creates 2 sparks each time rather than 1.

AndrewH

[twinturbo]

For Info.. There are ( from memory ) 3 types of sierra Rev counter, which should be marked on the face

4 - 4 Cylinder Single Coil
6 - 6 Cylinder Single Coil
C - Cosworth 4 Cylinder

You may also find other ford rev counters

2 - 4 cylinder wasted spark



TT

[themaninthesuitcase]

Sounds like i have the only edis connector in the country without the output for the rev counter! :D
Mine doesn't either! I think it comes down to if the donor had a counter or not.

Lots of people I know have drilled and just shoved in a wire, but personally I'd rather disassemble the plug (which is possible, I have a link at home somewhere) from two cars and then use one of the spare plug bits on that pin. However for testing just shoving in a wire will work.

That or a bit of scrappy diving to find one with all the outputs when you go looking for the second plug.

[mark]

After the info from yesterdays replies i spent a while tinkering in the garage when i finished work. Drilled through the edis connector to get to pin 2 on the edis, managed to get a wire from there to the rev counter then fired up the engine. It seems to be reading a little low compared to the readout on the megajolt software on the laptop.

So next i tried connecting to the signal wires going to the coilpack, i wired in a couple of diodes and then tried this which seems a little better. Its quite hard to tell if its reading properly though because i cant rev it too much as its only got a manifold on and is ridiculously loud even at tickover :eek: :D

Just waiting for a 60mm stainless bend coming then i can get my silencer on and try revving it a bit more to find out for sure. At least its actually reading something now though, so its a step in the right direction. I was only using donor instruments for speedo accuracy at iva and ease of fitment, turns out the time ive spent mucking about with a new fuel sender and now the rev counter it would have been just as easy to go with all new clocks :rolleyes:

[richardk]

I had to do the diode thing off the coil pack and although it wanders a little its pretty accurate up to about 4k then seems to under read so don't use it at iva, ask them to use their rev counter that clips onto an ht lead or you'll be reving the nuts off your motor and it'll be louder than necessary possibly giving you an incorrect fail.

Cheers

Rich

[mark]

Good advice, thanks :)