paul_treg said:
The rev counter signal is a separate output pin from the ecu, if you get pulses from the crank sensor and it is 36 tooth, in theory a 4 cylinder counter will read 9 times the actual RPM. 12 cylinder counter should read 3x actual.
Technical Rev counter
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Technical Rev counter
The rev counter signal is a separate output pin from the ecu, if you get pulses from the crank sensor and it is 36 tooth, in theory a 4 cylinder counter will read 9 times the actual RPM. 12 cylinder counter should read 3x actual.
fixitagaintomorrow said:
Hi,
Its not the teeth I need to count, but the gap in the teeth, at some point on the timing pulley there should be a few teeth missing to tell the engine where TDC is, the rev counter should read this signal......I am hoping..
Thanks
Paul T
The sensor will pick up all 36 teeth and the gap, so might be tricky. Not impossible though, good luck 
helicopter_red
New member
Hi just a thought! i checked the wiring diagram of 900cc and sporting and noticed that they both have twin coils and the rev counter signal is from the ECU so if you could persuade somebody with reliable drawings to determine what each pin from ecu does, because normally it is all there in the ecu waiting to be used but was never used by fiat as these circuit boards are mass produced to cater for all models (USUALLY)
i know this to be true with fords as i have succsessfully wired a mondeo fuel computer into my mk7 escort, the pin outs where the same but unused on the escort.
Remember to check a reliable source of electrical drawings before messing with the ecu because if you get it wrong you could wreck it
hope this my be helpfull but check before messing as i dont know much about fiats yet i am assuming the ECU would be made to cover a wide variety of models like they do with fords!!!
Cheers HR
i know this to be true with fords as i have succsessfully wired a mondeo fuel computer into my mk7 escort, the pin outs where the same but unused on the escort.
Remember to check a reliable source of electrical drawings before messing with the ecu because if you get it wrong you could wreck it
hope this my be helpfull but check before messing as i dont know much about fiats yet i am assuming the ECU would be made to cover a wide variety of models like they do with fords!!!
Cheers HR
Hi,
One spark per rotation of a 4 stroke, 4 cylinder engine.
i.e. each piston has to go up and down 4 times before a spark, each piston is offset by one stroke, so a different one of the four fires every rotation.
This is where I get the idea of using the crank pulley, one big gap passes the sensor every rotation, same as one spark every rotation..
Thanks
Paul T
One spark per rotation of a 4 stroke, 4 cylinder engine.
i.e. each piston has to go up and down 4 times before a spark, each piston is offset by one stroke, so a different one of the four fires every rotation.
This is where I get the idea of using the crank pulley, one big gap passes the sensor every rotation, same as one spark every rotation..
Thanks
Paul T
Paul...what year of Cinq you got?
All Cinqs past 9/95 use the 16F ECU model with different maps for the 1108cc and 899cc...
eg: 16F.ER might be 1108cc (Cant Remember)
16F.xx where xx is the map code, that refers to the map the ecu has ..
Least thats how I think it is...cos it would explain why first half of all the codes tally up and both Cinq's use the same no of sensors..
All Cinqs past 9/95 use the 16F ECU model with different maps for the 1108cc and 899cc...
eg: 16F.ER might be 1108cc (Cant Remember)
16F.xx where xx is the map code, that refers to the map the ecu has ..
Least thats how I think it is...cos it would explain why first half of all the codes tally up and both Cinq's use the same no of sensors..
chaos said:
Hi,
Same amount of sparks per rotation, but with twin coil, each coil takes it in turns to supply a spark every rotation......but there is one spark every rotation.
Hope I haven't confused anyone.........
Thanks
Paul T
arseofbox said:
Hi,
6/94........The haynes manual says they have different ecu's, I haven't actually seen a sporting ecu so I can't confirm what it says in the manual, but from the wiring diagram there are a few more pins
Thanks
Paul T
helicopter_red
New member
Hi i have compared haynes manual which shows an 899 with the porter manual which shows a sporting and according to these (and they both seem to agree) you want pin no 23 on ECU or the black and violet wire on the fuel pump relay (which i imagine would be easier to get to without risking any damage to the ecu) I havent checked mine yet but i will check mine in the next couple of days when i get a chance and let you know!
hope this helps HR
hope this helps HR
Hi,helicopter_red said:
Yeah I see where your coming from, fitted the sporting clocks today, swapped the speedo for my 899cc unit and found the black/violet wire, but run out of light before could run the new cable. The black/purple wire is the thin wire on the relay closest to the brake fluid reservoir.....may actually be getting some where..
Thanks
Paul T
so what are you doing just fitting sporting clocks and then connecting a wire to one that is already there or is more complex
The younger modder said:
Hi,
More or less Yeah, In mine sporting clocks with 899cc speedo to keep my speed reasonably accurate, but this wire should be able to be used for aftermarket rev counters, as other people have connected sporting clocks to one of the coils and had a reading of half normal, so this wire should give a signal that combines the two coils........I think anyway..
Thanks
Paul T
Hi,
Checked the black/violet wire and there is a signal that varies with engine revs, couldn't pick up the frequency with my multimeter but could pick up a change in ac voltage, about 1.6Vac at idle to about 3.4Vac at about 4krpm, looking good so far......
Thanks
Paul T
Checked the black/violet wire and there is a signal that varies with engine revs, couldn't pick up the frequency with my multimeter but could pick up a change in ac voltage, about 1.6Vac at idle to about 3.4Vac at about 4krpm, looking good so far......
Thanks
Paul T
helicopter_red
New member
Hi there yeah i have checked mine and im getting a frequency output so we are just waiting on you to connect it up and see if it works, just hope that they havent put a duff program in the ecu so the output is useless Fingers crossed HR
I've just picked up on this post, and have a question.
I wired in my halfords tacho, and it reads exactly half. I tried connecting the wire to both coils, but this ended up shorting something, causing the engine to stall.
If i were for example to put some kind of diode (led) between the 2 coils when connecting them up together, the signal would not be able to travel back on itself causing the stall, am I right?
Adam
I wired in my halfords tacho, and it reads exactly half. I tried connecting the wire to both coils, but this ended up shorting something, causing the engine to stall.
If i were for example to put some kind of diode (led) between the 2 coils when connecting them up together, the signal would not be able to travel back on itself causing the stall, am I right?
Adam
cinqysxmk2 said:
Hi,
Yeah I thought about that one a while ago(not an led though), it would depend on the signal needed by the rev counter, you may half the signal but keep the right frequency, why don't you try the black/violet wire on the fuel pump relay, it may give out the signal you require....? or you could try the output from the crank sensor...?
Thanks
Paul T
