Rev counter stopped working when fitted electronic ingnition

R

Richard Thorley

Member
I've just bought my P6 3500S. One the thing is that the Rev counter does not work. It was suggested by the previous owner that it stopped working when he fitted the electronic ignition. I've not heard of this before. I don't know the brand of electronic ignition but it is the type that fits into the distributor. Any ideas if this is correct
 
Hi Richard,
There are a couple of types of rev counters fitted to series 2s, it depends on chassis suffix number and are not normally interchangeable.
I think it was early suffix A cars that can suffer from rev counter flicking when in use.
My dads early car used to do that and he sent it off to a company called speedy cables who fixed it but that was many years ago when he fitted his luminition kit
Not had any rev counter issues on later cars with same ignition systems that i have fitted.
Cheers,
Clive.
 
I've just started to have a fresh look at this. The wire for the Rev counter is grey and white according to the wiring diagram and this is conceded yo the negative side of the coil according to the diagram this is right but I notice if I put this wire to the positive side of the coil when the engine turns over the Rev counter works but the engine won't start. I also have two wires both yellow and white (one thicker than the other) which are not connected but appear as they shoukd be connected to the coil in fact there is a crimp connector that one of those wires might belong to. Is my original problem connected to these in some way I have tried to connect them up with no difference. Any ideas anyone. The electronic ignition that was fitted is a pertronix ignitor if anyone has known any problems with test though the car runs great. I've added a pic of the wires to the coil. I took the ht lead off for the photo
 

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I have heard of this. When I bought electronic ignition for my other car (a 260Z) I was warned that it had to be fitted correctly otherwise it could lead to the rev counter not working. I never did understand why. Anyway, because of this, I paid an auto electrician to do the job and there was no problem. It is obviously something that can happen to older cars when you fit electronic ignition. If you spoke to an auto electrician (or maybe got one to take a look) I am sure they could put that right. Good luck.
 
The two white/yellow are part of ballast system and presumably not used with the electronic ignition. They should be taped up though as they are still live, if not disconnected the other end. I am intrigued by the other wire connected to the + terminal , looks brown in the photo.
 
There are 2 different models of REV counter used in the series II models, the earlier one I believe is a current sensing unit and wont work with the electronic ignition and the later is a voltage sensing unit and does work. Both units look identical on the outside, if you do a search of the forum you will find other discussions on this problem and how to identify each of the models of counter. I would suggest finding the later counter and replacing the old.
My car also has the Pertronix unit and operates the counter perfectly.

Graeme
 
Had a look at my rev counter which is the RVI type which I think makes it the earlier one and hence it won't work with the electronic ignition. I'm guessing the only way to sort it is to get a later instrument set.

Are the instruments in general a bit unreliable? I have a speedo that wanders all over the place though is suspect that will be a worn cable
I have a petrol gauge with a mind of its own. Doesn't always read full when I brim the tank then at other times wants to show 3/4 full when I know it's nearly empty. The only gauges that are steady are the amps and temp though I suspect they might just be trying to lul me into a false sense of security ☺
 
the instruments themselves are very reliable, its the input that isnt. A lot of 70's cars had issues with the dash soldering but I cant say I have seen problems with the P6 dash.
The speedo wandering about is usually the cable or the right angle drives that go into it (lubrication can be efficacious) Fuel tank irregularities are more likely the sender, oil pressure woes are usually the sender same for water temp.
 
Richard Thorley said:
Had a look at my rev counter which is the RVI type which I think makes it the earlier one and hence it won't work with the electronic ignition. I'm guessing the only way to sort it is to get a later instrument set.

Are the instruments in general a bit unreliable? I have a speedo that wanders all over the place though is suspect that will be a worn cable
I have a petrol gauge with a mind of its own. Doesn't always read full when I brim the tank then at other times wants to show 3/4 full when I know it's nearly empty. The only gauges that are steady are the amps and temp though I suspect they might just be trying to lul me into a false sense of security ☺
Click to expand...
I got the cable and the angle drive behind the actual speedo lubricated on mine (after advice from another member) and it has taken a lot of the wobble out of the speedo needle. Now it just trembles a little bit!
 
I managed to get hold of another rev counter to try this one being an rvc type. However as I removed the old rev counter I could see 3 wires connected. One was a spade connector and two were like bullet connectors that pushed into two protruding connections stiking out of the back of the counter. The new one however only as one of the protruding connectors and the spade connector. Is this right or have I got my self a broken connection
 
Hi.
The 3 connector type is the early RV1
3500 cars up to chassis d
3500s cars up to chassis c
RVC type
3500 from chassis e
3500s from chassis d
Clive.
 
So if I fit a later type rvc what do I do about the extra connection. I've deliberately tried to fit an rvc type as they are supposed to work with electronic ignition. Any advice would be great thanks
 
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