(T) Coil on Seicento S for Rev counter

Hi

Im currently attempting fitting an aftermarket rev counter like Malin Dixon did to a cinq. (By changing the resistor inside the rev counter).

http://www.fiatforum.com/showpost.ph...&postcount=135

However, I now want to connect it to pin 19 from the ecu which is one of the coils. Its tricky to get too and i dont want to damage the plug. Can anyone tell me where to find an easier place to connect to the wire!

Thanks

You read the thread in the FAQs, if anybody know's it'll most likely be there.

There is no solution in the FAQ for fitting a rev counter to a Sei only a for Cinq. It seems that all the solutions suggested dont work for a sei. I am in the middle of fitting the sporting rev counter to my SX but still no luck in finding a signal feed for it. My car also has the rev counter plug under dash so I thought I could just plug it straight in and it would work but this is not the case.

Any working solution you do find I would love to hear about, as I said above you would be the first to get it to work in a standard sei. Hope this hasnt put you off.

Matt925

I don't know if the Seicento has similar coils to a Cinquecento, but if so you could just as well get the signal from either coil connector.

The circuit is very simple. Power from ignition switch goes to one end of the low voltage side of each coil. (Light blue wire on Cinquecento). Other end of the low voltage side of coil goes to ECU (light blue / red on one coil white / green on the other). ECU connects this to earth and disconnects when spark is wanted. It is just like the old contact breaker system, but with electronic switches in place of the contact breaker.

I didn't want to connect to near the coil as I couldn't see a way of doing it while keeping things waterproof, but you could join anywhere on either wire that connects a coil to the ECU. The plug that connects to the ECU can be unscrewed on our Cinquecento.

Those rev counters will work on just about any spark ignition engine. The biggest issues are finding the coil wire and setting the rev counter to the correct number of cylinders, which is the number the coil supplies, not the total for the car.

It is not very neat to take a signal from the coil. It is neater to take a signal from the ECU, which uses the crankshaft sensor to know the revs. This is what FIAT do when they fit a rev counter. However, cars not fitted with a rev counter from new may not have the right signal from the ECU, so a FIAT rev counter won't work.

It is quite possible that one of the spare connectors on the ECU, that has no wire going to it, is for a rev counter. I didn't go looking.

Hi Malin,
I was told that the Sei does not have ignition coils like the cinq does hence this solution not working on the Sei.
I have tried to do all the solutions on the FAQ but I cant seem to get any of them to relate to the Sei. I dont feel confident enough to start unplugging the ECU and start tampering with stuff there unless I know a cast iron solution that will actually work!
Is the crankshaft sensor the one that runs of the big toothed type gear on one side of the engine (excuse the none technical description!!). Would it be possible to get the signal for the rev counter by patching the wire from the cable that runs from this?
There must be a signal from somewhere to operate a rev counter its a basic engine?
I read in the haynes max power book where they showed the rev counter getting its signal from the diagnositc plug (this was on a saxo). Would something like this be possible on a Sei and where is the diagnostic plug?
I really wanna get this working now for me this problem has dragged on for 9 months now!!

Matt925

You're right this has been going on too long!

I could really do with the ECU wiring diagram because I assumed it was twin coil to ECU pins 1 and 19 but pin 19 doesnt have any connection in my Sei MPI.

I've read the previous threads countless times and that seems to say something about pin 23 having a violet-black wire but my pin 23 has a grey-red wire!

Does anybody have an ECU wiring diagram for a Seicento 1.1? Or can anyone tell me where the coil (s) wiring is in the engine bay with a picture or something.

Thanks for the previous replies.

All petrol engines have coils. If you can connect to the low voltage side of the coil, you can get a rev counter to work.

All I did was adjust the rev counter to read correctly for the twin coil Cinquecento, instead of the single coil set-up that the rev counter was designed for.

The connection to pin 1 or 19 of the Cinquecento was the easiest place for me to connect to the the low voltage side of a coil, but I had the circuit diagram in the Haynes manual.

Matt925, the thing you describe is the crankshaft sensor. The frequency coming from that will tell you the engine revs. However, no rev counter will be calibrated to read anything like the right revs and the voltage may be very small. Also, connecting a wire to it could mess up the signal and stop the engine.

I know that some Fiats have a signal from the ECU to drive a rev counter. This is better because a faulty rev counter can't stop the engine. However, I have no idea whether the signal is present on all ECUs, or what type of signal it is or if it varies from model to model.

Just keep it simple and connect to an igniton coil.

Ok then my next question is where are the ignition coild located on my Sei or what should I be looking for?
Mikey543 I belive there was a ECU diagram on the FAQ for rev counters explaining what each pin is for if you havent already got it. Pin 23 is correct for attaching a rev counter to I have read that in someones fiat workshop manual that is where the signal. If you have identified it then it might be worth trying I was told that sometimes the wiring colour changes from model to model. How did you get access to the ECU did you unplug it?

Interestingly Autodata does not list a pin diagram beyond 2000.

The coils are on the opposite end of the cylinder head from the cam pulley

Cheers

D

Yes I unplugged it and unclipped the plastic surround to the plug.

The wiring diagram doesnt seem to be right unless I've looked at the wrong one. The one I saw was for a Punto 1.2 and the thread said that the ECU wiring would be the same.

I'm going to wait a couple of days then try a couple of wires from the ECU until I get a coil signal. I know this will be half revs but Malin Dixon got round this.