Duff Coil - perhaps...
Discussion
Well after a great second run down to Huddersfield on monday and a blast over the woodhead pass on monday night, I was tootling around Huddersfield on the way back from Halfrauds when ... ... nothing ! the engine just stopped and I cruised to an ignominious halt outside a Suzuki dealership. checked plug - no spark, checked main HT lead from coil - no spark, checked wires to coil with ignition on and 12 volts OK - so duff coil (?) called RAC and he confirmed what I already knew but then suggested it may not be the coil and may be the ECU ! 
he left and after another hour the recovery man turned up and I eventually got home at 2.00 am this morning...
So what do you think? coil or ecu ? I plan to get a new coil and hope that cures it... but if not, what next ?
suggestions on the back of a tenner please !
K
he left and after another hour the recovery man turned up and I eventually got home at 2.00 am this morning...So what do you think? coil or ecu ? I plan to get a new coil and hope that cures it... but if not, what next ?
suggestions on the back of a tenner please !
K
OK you have 12v at the coil so that confirms ignition circuit is working - rules out ignition switch or the infamous connector block.
But you only get a spark from the coil if the "pulse" signal works - ie the LT signal switches off the current through the LT windings to create the HT spark - and that signal comes from the ecu, which itself relies on a signal from the Hall sensor (the electronic version of the good old contact points) in the distributor (so that the spark happens at the right time, see?)
So to help you along (not) the fault could be in the coil, the ecu or the distributor. Or the wiring between the three. Or the connections at the coil or distributor.
I would start by checking all the connections especially at the coil and distributor, and the visible wiring to both, and then, like you, by substituting the coil (first by borrowing a known working unit rather than buying one).
Also - think what you may have been working on recently that might have stretched or dislodged a wiring connection.
But you only get a spark from the coil if the "pulse" signal works - ie the LT signal switches off the current through the LT windings to create the HT spark - and that signal comes from the ecu, which itself relies on a signal from the Hall sensor (the electronic version of the good old contact points) in the distributor (so that the spark happens at the right time, see?)
So to help you along (not) the fault could be in the coil, the ecu or the distributor. Or the wiring between the three. Or the connections at the coil or distributor.
I would start by checking all the connections especially at the coil and distributor, and the visible wiring to both, and then, like you, by substituting the coil (first by borrowing a known working unit rather than buying one).
Also - think what you may have been working on recently that might have stretched or dislodged a wiring connection.
tvrgit said:
OK you have 12v at the coil so that confirms ignition circuit is working - rules out ignition switch or the infamous connector block.
But you only get a spark from the coil if the "pulse" signal works - ie the LT signal switches off the current through the LT windings to create the HT spark - and that signal comes from the ecu, which itself relies on a signal from the Hall sensor (the electronic version of the good old contact points) in the distributor (so that the spark happens at the right time, see?)
So to help you along (not) the fault could be in the coil, the ecu or the distributor. Or the wiring between the three. Or the connections at the coil or distributor.
I would start by checking all the connections especially at the coil and distributor, and the visible wiring to both, and then, like you, by substituting the coil (first by borrowing a known working unit rather than buying one).
Also - think what you may have been working on recently that might have stretched or dislodged a wiring connection.
Ok thanks for that... I will start with the connections and physical stuff I can see, I'm not sure about substitution of another coil yet as I'm not sure what i should use (or even what I have got - hence other thread) I saw your previous thread advising Clarenceboddiger not to use a Lucas DLB125 so dont know where I am with that yet but whatever, I think it would be good to have a spare anyway when I figure out what to get.But you only get a spark from the coil if the "pulse" signal works - ie the LT signal switches off the current through the LT windings to create the HT spark - and that signal comes from the ecu, which itself relies on a signal from the Hall sensor (the electronic version of the good old contact points) in the distributor (so that the spark happens at the right time, see?)
So to help you along (not) the fault could be in the coil, the ecu or the distributor. Or the wiring between the three. Or the connections at the coil or distributor.
I would start by checking all the connections especially at the coil and distributor, and the visible wiring to both, and then, like you, by substituting the coil (first by borrowing a known working unit rather than buying one).
Also - think what you may have been working on recently that might have stretched or dislodged a wiring connection.
I'm pretty sure I've not fiddled with anything on these circuits although I have added Spirap to tidy up the wiring so maybe I have dislodged something - good tip. the ECU implications scare me...
GreenV8S said:
You can test the coil by briefly shorting the -ve terminal to earth, it should produce a spark when you remove the short. This tests the coil itself; if this is OK then the next thing to suspect would be the ignition amplifier which drives it.
Thanks Peter - any idea where the ignition amplifier is located (state all options as its a TVR )ketvrin said:
GreenV8S said:
You can test the coil by briefly shorting the -ve terminal to earth, it should produce a spark when you remove the short. This tests the coil itself; if this is OK then the next thing to suspect would be the ignition amplifier which drives it.
Thanks Peter - any idea where the ignition amplifier is located (state all options as its a TVR )Anyway, the ignition amplifier or whatever is simply the "contactless contact breaker" circuit in the distributor - as the distributor shaft turns, it sets off a magnetic or electronic sensor alongside, which replaces the "points opening and closing" in older cars. When the circuit is "made", the coil effectively "charges" the HT circuit by magnetic interference blah blah blah scientific stuff... When the "points" open, the HT circuit discharges through a spark. That is why the other tip, about earthing and then opening the -ve terminal on the coil, should give a spark.
Anyway, the amplifier is part of the distributor - there is a 3-wire (or maybe 4-wire, I can't remember) connector that comes out of the distributor casing just below the cap. On my car, it points towards spark plug number 3, under the heater hoses. That connector goes in to the ignition amp module in the distributor.
tvrgit said:
I think Peter's "ignition amplifier" and my "Hall sensor" mean the same thing
A conventional electronic ignition system has a sensor (aka pickup) inside the distributor that produces a weak electrical signal, and an amplifier which takes this signal and switches the main current through the coil on and off to produce the spark. The amplifier may be mounted on the side of the dizzy or the side of the coil or elsewhere. It is always electrically connected to the pickup (inside the distributor) and to the coil, so usually easy enough to locate by following wires. In my experience the pickup tends to be very reliable but the amplifier is less so. You can use the test I described earlier to see if the coil works. If it does, but you still don't have a spark at the coil, this implies a pickup/amplifier/wiring fault. It is easy to test the wiring and if this seems OK the amplifier would be the main suspect. If you prove that the amplifier is OK then consider the possibility that the pickup is faulty, but I'd only come to this conclusion reluctantly.Sorry - Peter's right. I have never looked too closely but always thought that the amplifier was INSIDE the distributor on the V6, and the connector came out. Checked the trusty Granada manual last night and I see that the amplifier module is held onto the side of the distributor with 2 set screws, and the wiring connector goes into that.
The "Hall sensor" is the magnetic pulse pickup inside the distributor that detects where the distributor shaft is, so creates the signal at the right time.
Sorry for any confusion, but happy to clarify!
The "Hall sensor" is the magnetic pulse pickup inside the distributor that detects where the distributor shaft is, so creates the signal at the right time.
Sorry for any confusion, but happy to clarify!
Yep tha helps cheers, I'm going to have a look today. I saw your photo ofyour coil on the other thread too and yours (square coil)is different to my set up. I won the ebay lucas DLB125 coil for £9.99 - fingers crossed its OK.
The wiring diagrams are quite confusing if I compare the TVR bible diagram with the Haynes Sierra V6 diagram so I'm just going to have to accept that the wiring on mine is correct but might have a fault if you see what I mean as the colours are different to both bible and haynes - Duh. I found a twisted connection buried beneath the insulation so will sort out any dodgy connections on my way.
thanks for the help
K
The wiring diagrams are quite confusing if I compare the TVR bible diagram with the Haynes Sierra V6 diagram so I'm just going to have to accept that the wiring on mine is correct but might have a fault if you see what I mean as the colours are different to both bible and haynes - Duh. I found a twisted connection buried beneath the insulation so will sort out any dodgy connections on my way.
thanks for the help
K
Duff Coil... ? NO ! its not duff and the new one didnt cure my problem so I followed the advice given so far and as there was no HT spark when shorting the negative terminal of the coil I concluded it was a duff module. Just as GreenV8s suspected - cheers Peter
I had to remove the dissy to get the module off but had to use a borrowed long reach socket to loosen the screws - Ford dealer didnt have a socket the correct size, but helpfully quoted £88.17 + VAT for a new module - which they did not have. mine is the same as this one on the intermotor site as mine is a motorcraft E5RF-12A297-BA unit = Intermotor 15310 = Lucas DAB750
http://partfinder.smpeurope.com/?p=154 - click on search on this page...
so I'm searching for a replacement and aim to beat the local Ford dealer price... anyone bought one lately and can recommend anywhere ?
I had to remove the dissy to get the module off but had to use a borrowed long reach socket to loosen the screws - Ford dealer didnt have a socket the correct size, but helpfully quoted £88.17 + VAT for a new module - which they did not have. mine is the same as this one on the intermotor site as mine is a motorcraft E5RF-12A297-BA unit = Intermotor 15310 = Lucas DAB750
http://partfinder.smpeurope.com/?p=154 - click on search on this page...
so I'm searching for a replacement and aim to beat the local Ford dealer price... anyone bought one lately and can recommend anywhere ?
http://www.classic-car-accessories.co.uk/acatalog/...
scroll down to about halfway
There is also one on ebay 99p start but has ten days to go
Item number: 330135275821
scroll down to about halfway
There is also one on ebay 99p start but has ten days to go
Item number: 330135275821
Edited by pies on Saturday 16th June 16:46
pies said:
That is superb Colin Cheers ! I have just ordered one for £16 delivered ! somewhat better than the Ford price eh.Hope you got your brakes sorted...?
K
tvrgit said:
OK you have 12v at the coil so that confirms ignition circuit is working - rules out ignition switch or the infamous connector block.
I'm really fed up now...
I had 12 v to the coil so went further downstream and have now replaced the coil and the module and still no sparks, so I start from first principles and check the voltage to the coil and now find I have 2.5v only to the coil !!! WTF? 
So I start exploring the ignition switch area looking for bad connections and "the infamous connector block" ? where is that Andrew ?
problems here are -
1) electrics are not my strong point (you'll have figured that for yourself by now...
2) there are the remains of two alarm systems connected in to the wiring in this area and the wiring looks a right pigs trifle with twisted connections (soldered) and loose ends all over the shop.
3) the bible (first edition) wiring diagram has only a passing resemblance to my cars wiring...
any suggestions welcome
K
Here's a pic of the "infamous connecter block" that sits under the steering column next to the ignition switch.
The black and yellow bit are joined normally but when pulled apart the problem became apparent. I cut the leads for that contact and joined them dirrectly. If you haven't already got one then get a ratchet crimping tool and loads of connectors. It's a TVR and you need them.
On mine that connector caused issues with the dash instruments reading incorrectly as the load increased - like using the headlights and fan.
The black and yellow bit are joined normally but when pulled apart the problem became apparent. I cut the leads for that contact and joined them dirrectly. If you haven't already got one then get a ratchet crimping tool and loads of connectors. It's a TVR and you need them.
On mine that connector caused issues with the dash instruments reading incorrectly as the load increased - like using the headlights and fan.
Gassing Station | S Series | Top of Page | What's New | My Stuff