Ignition Amp Testing? Still won't start...
Discussion
I'm quit pleased with myself. I got out the old soldering iron, got some bulbs, found some wire. Bobs your uncle.
So the results...
When I turned on the ignition (no cranking) both bulbs came on full.
On cranking both flicker with the revs.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
John what do you think now?
So the results...
When I turned on the ignition (no cranking) both bulbs came on full.
On cranking both flicker with the revs.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
John what do you think now?
Edited by frubes on Monday 30th March 19:21
[quote=frubes]When I turned on the ignition (no cranking) both bulbs came on full.
Thats expected
On cranking both flicker with the revs.
Thats not right, the POS bulb must not flicker, its on a solid 12 volts - but in your case the engine is cranking, thereby dropping the voltage causing the flickering. It may invalidate the test but not if you could feed the ignition from a sepaerate 12 volt battery for the test
NEG flickering with rpm is expected and suggests no fault in amplifier or coil.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Its true that an amplifier may shows signs of instability before it eventually becomes toast. Their average lifetime is 60-80000 miles. When mine started to play up the situation lasted undiagnosed for six months before it finally went AWOL.
However you have not described a fault condition, you said NEG is flickering with revs.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
Thats a mistaken assumption, it might be ignition but not for that reason. Too much fuel will prevent combustion due to being a non-combustible mixture, and/or the sparks being quenched by flooding. Re-view this instruction, it does not ask for a steady voltage.
6 Check if the injectors are actually firing whilst cranking by putting a bulb or volt meter across an injector whilst cranking and watch if it flickers.
If you have a steady voltage of three volts the injectors are full on suggesting an ECU failure, If you have a steady voltage of 12 volts the injectors are not being fired at al lsuggesting a different fault condition.
John what do you think now?
Like many people your understanding of ignition systems is very sketchy. the following component explanations may help.
The Basic Components and their Functions Read in conjunction with the circuit diagram posted earlier.
From battery through to spark plug and beyond, these are the key components involved in generating the bright blue spark that ignites the awaiting air/fuel mixture and they must all work flawlessly for maximum engine efficiency.
A Battery in good condition, capable of lighting the blue touch paper even whilst churning a reluctant lump on a freezing cold day.
An Ignition Switch with four key positions: 1, Off, 2, Accessories, 3, Ignition On and 4, Cranking. The latter two positions both supply 12 volts to make the ignition circuit come alive.
A Distributor with three tasks. 1, Determine the exact moment during the cycle to generate a signal pulse to ignite the touch paper, 2, Route the resulting spark to the right firework, and 3, Advance the ignition timing according to either inlet manifold vacuum or engine speed.
A Vacuum Advance Module that senses manifold depression as soon as the throttle plate moves away from the idle position and advances the timing to capture maximum efficiency from the upcoming explosions at low engine speed, then passing over ignition advance responsibility to -
The Mechanical (Centrifugal) Advance Mechanism that uses bob weights and springs to control the amount of ignition advance according the engine speed and rate of acceleration.
A Magnetic Rotor with eight peaks produces a pulsing magnetic field adjacent to -
A Pick-up Coil that generates its own output (like an alternator, so not needing a voltage supply) to send a synchronised sine wave signal through its two electrical connections to -
An Amplifier Module already connected between Coil negative and earth that responds instantly to the incoming signal, switching a path to earth for the negative side of -
The Coil, actually a transformer which converts the switched current from the battery into 30,000 volts capable of bridging gaps of up to15mm with a bright blue lightening strike.
A Condenser (or Capacitor) connected into the low voltage circuit across the coil/amplifier combo to suppress Radio Frequency signals otherwise destined upset in-car entertainment systems and offend un-neighbourly soap addicts watching their TV’s. It is also perceived to assist in rapidly collapsing the coil primary voltage for a sharper high voltage discharge.
A King Lead connects the high voltage terminal of the coil to the centre turret terminal of -
The Distributer Cap that receives and transfers the high voltage discharges to the -
The Rotor Arm which allocates the lethal sparks to one of eight turrets connected to -
The High Tension Leads with a particular internal impedance, resistance or other RF suppression characteristic, terminating at the prickly -
Spark Plugs where a flash of highly charged electrons ignite the expectant air/fuel mixture inside the combustion chambers, such that, under all the various engine conditions, its exact occurrence is determined by -
The Ignition Timing, not in itself a component, but a critical function, often maladjusted.
A Trigger Resistor connects signals generated at coil negative, to Pin 1 of the ECU to notify it the engine is running and please keep injecting fuel until these pulses cease.
The same signals from coil negative also go off to the Tachometer to indicate engine rpm and to the Cruise Control over-speed relay for engine protection if the Cruise ECU tries to accelerate the engine when the transmission or gearbox is disengaged.
Thats expected
On cranking both flicker with the revs.
Thats not right, the POS bulb must not flicker, its on a solid 12 volts - but in your case the engine is cranking, thereby dropping the voltage causing the flickering. It may invalidate the test but not if you could feed the ignition from a sepaerate 12 volt battery for the test
NEG flickering with rpm is expected and suggests no fault in amplifier or coil.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Its true that an amplifier may shows signs of instability before it eventually becomes toast. Their average lifetime is 60-80000 miles. When mine started to play up the situation lasted undiagnosed for six months before it finally went AWOL.
However you have not described a fault condition, you said NEG is flickering with revs.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
Thats a mistaken assumption, it might be ignition but not for that reason. Too much fuel will prevent combustion due to being a non-combustible mixture, and/or the sparks being quenched by flooding. Re-view this instruction, it does not ask for a steady voltage.
6 Check if the injectors are actually firing whilst cranking by putting a bulb or volt meter across an injector whilst cranking and watch if it flickers.
If you have a steady voltage of three volts the injectors are full on suggesting an ECU failure, If you have a steady voltage of 12 volts the injectors are not being fired at al lsuggesting a different fault condition.
John what do you think now?
Like many people your understanding of ignition systems is very sketchy. the following component explanations may help.
The Basic Components and their Functions Read in conjunction with the circuit diagram posted earlier.
From battery through to spark plug and beyond, these are the key components involved in generating the bright blue spark that ignites the awaiting air/fuel mixture and they must all work flawlessly for maximum engine efficiency.
A Battery in good condition, capable of lighting the blue touch paper even whilst churning a reluctant lump on a freezing cold day.
An Ignition Switch with four key positions: 1, Off, 2, Accessories, 3, Ignition On and 4, Cranking. The latter two positions both supply 12 volts to make the ignition circuit come alive.
A Distributor with three tasks. 1, Determine the exact moment during the cycle to generate a signal pulse to ignite the touch paper, 2, Route the resulting spark to the right firework, and 3, Advance the ignition timing according to either inlet manifold vacuum or engine speed.
A Vacuum Advance Module that senses manifold depression as soon as the throttle plate moves away from the idle position and advances the timing to capture maximum efficiency from the upcoming explosions at low engine speed, then passing over ignition advance responsibility to -
The Mechanical (Centrifugal) Advance Mechanism that uses bob weights and springs to control the amount of ignition advance according the engine speed and rate of acceleration.
A Magnetic Rotor with eight peaks produces a pulsing magnetic field adjacent to -
A Pick-up Coil that generates its own output (like an alternator, so not needing a voltage supply) to send a synchronised sine wave signal through its two electrical connections to -
An Amplifier Module already connected between Coil negative and earth that responds instantly to the incoming signal, switching a path to earth for the negative side of -
The Coil, actually a transformer which converts the switched current from the battery into 30,000 volts capable of bridging gaps of up to15mm with a bright blue lightening strike.
A Condenser (or Capacitor) connected into the low voltage circuit across the coil/amplifier combo to suppress Radio Frequency signals otherwise destined upset in-car entertainment systems and offend un-neighbourly soap addicts watching their TV’s. It is also perceived to assist in rapidly collapsing the coil primary voltage for a sharper high voltage discharge.
A King Lead connects the high voltage terminal of the coil to the centre turret terminal of -
The Distributer Cap that receives and transfers the high voltage discharges to the -
The Rotor Arm which allocates the lethal sparks to one of eight turrets connected to -
The High Tension Leads with a particular internal impedance, resistance or other RF suppression characteristic, terminating at the prickly -
Spark Plugs where a flash of highly charged electrons ignite the expectant air/fuel mixture inside the combustion chambers, such that, under all the various engine conditions, its exact occurrence is determined by -
The Ignition Timing, not in itself a component, but a critical function, often maladjusted.
A Trigger Resistor connects signals generated at coil negative, to Pin 1 of the ECU to notify it the engine is running and please keep injecting fuel until these pulses cease.
The same signals from coil negative also go off to the Tachometer to indicate engine rpm and to the Cruise Control over-speed relay for engine protection if the Cruise ECU tries to accelerate the engine when the transmission or gearbox is disengaged.
Edited by honestjohntoo on Monday 30th March 20:37
frubes said:
I'm quit pleased with myself. I got out the old soldering iron, got some bulbs, found some wire. Bobs your uncle.
So the results...
When I turned on the ignition (no cranking) both bulbs came on full.
On cranking both flicker with the revs.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
John what do you think now?
Poking meters at the injectors won't tell you much. I won't confuse the issue so I'd say you're right, as you have fuel it's probably ignition related. One thing you could try is to pull off the white/black lead from the ignition amp to the ECU; there's usually a bullet connector in that wire somewhere under the airflow meter. Now the ECU won't try to fire the injectors. So whip out the cold start injector, pour a capful (not a cupful) of petrol in and replace. That'll give you more than enough fuel for at least a couple of cylinders to fire if they're going to at all.So the results...
When I turned on the ignition (no cranking) both bulbs came on full.
On cranking both flicker with the revs.
Now today I bought a new coil, so given Johns 3 options of, ignition module, coil, or recultor (not sure what that is)... And I now have a new coil, I'm going for ignition module?
My neighbour came over while i was playing and said on his old ford the ignition module used to go and it would misfire badly before hand, and as I said above the last couple of trips he has been running badly.
Also tried multimeter on injector. Was giving a voltage, and as fuel on plugs, it must be ignition?
John what do you think now?
Edited by frubes on Monday 30th March 19:21
The reluctor is the pickup coil in the distributor (replaces the points on old-fangled ignition
). Worryingly, there have been a few reported failures of them in the last couple of years, almost as though they're all reaching the end of their service life at the same time! When mine failed it took months to die, initially ithe car wouldn't rev past about 5500 (it normally goes way past 6000 if you're unsympathetic enough) and then one day she just wouldn't start at all... no sparks.If you suspect the ignition amp and/or reluctor, lay a spare sparkplug on the plenum with its HT lead connected to the coil. Pull off the two-pin connector from the amp, switch ignition on and using a length of wire in the lead that goes to the '-' side of the coil, stroke it across your plenum and watch for fat sparks. If you don't get any now, either the coil is kaput or you have a serious lack of supply to it!
The amp is only held by two screws, undo them and it unplugs. You can then measure the winding resistance of the pickup, it should be about 3000 Ohms. If it's much higher, say 5000+, it's probably duff... and if it's in the megohms region, it's definitely dead!
Incidentally if you don't want to pay through the nose for a genuine SD1 ignition amp, the same module was used on at least some Austin Metros...
OK, I was bored, so I scanned this in from my notes, in case you want to REALLy test your amp
:
Edited by Wedg1e on Monday 30th March 21:02
Thanks Both. This is really starting to baffle me know.
John, that is as i understood it. The only bit I am not exactly sure of if what the amp does. I thought in old cars the rotor arm made the connection from coil to plug to cause the spark and that was it.
Wedgie, when you said check the winding resistance, do you just mean check the resistance across the terminals while not connected.
Not sure what you meant by other test? Put an HT lead straight into top of coil, (where king lead goes), connect to plug, put on top of engine and see what happens?
John, that is as i understood it. The only bit I am not exactly sure of if what the amp does. I thought in old cars the rotor arm made the connection from coil to plug to cause the spark and that was it.
Wedgie, when you said check the winding resistance, do you just mean check the resistance across the terminals while not connected.
Not sure what you meant by other test? Put an HT lead straight into top of coil, (where king lead goes), connect to plug, put on top of engine and see what happens?
frubes said:
Thanks Both. This is really starting to baffle me know.
John, that is as i understood it. The only bit I am not exactly sure of if what the amp does. I thought in old cars the rotor arm made the connection from coil to plug to cause the spark and that was it.
The pickup in the distributor generates a titchy voltage in response to the rotor spinning past it. In order to be able to do anything useful, it is 'amplified' (by the amplifier John, that is as i understood it. The only bit I am not exactly sure of if what the amp does. I thought in old cars the rotor arm made the connection from coil to plug to cause the spark and that was it.
) and the output of the amp acts as if it was the points on an old system, in that it rapidly shorts the coil '-' to earth in a pulsing fashion.frubes said:
Wedgie, when you said check the winding resistance, do you just mean check the resistance across the terminals while not connected.
If you unplugged the ignition amp it would look like the thing above. The two terminals facing you (C & D) connect to the pickup inside the distributor; if you poked your meter across the terminals you can see with the amp removed, you ought to measure 3000 Ohms.frubes said:
Not sure what you meant by other test? Put an HT lead straight into top of coil, (where king lead goes), connect to plug, put on top of engine and see what happens?
Well, see what happens if you have a piece of wire connected to the coil '-' and you tap it (or stroke it) on the engine block or similar earth. That will simulate the coil being fired and you should see lots of sparks.Edited by Wedg1e on Monday 30th March 21:12
Wedg1e said:
If you suspect the ignition amp and/or reluctor, lay a spare sparkplug on the plenum with its HT lead connected to the coil. Pull off the two-pin connector from the amp, switch ignition on and using a length of wire in the lead that goes to the '-' side of the coil, stroke it across your plenum and watch for fat sparks. If you don't get any now, either the coil is kaput or you have a serious lack of supply to it!
Ian, Did you mean "with the king lead HT connected"? But thats an interesting inverted diagnosis for the amplifier etc.So! If sparks are not present when cranking, say, then, when stroking the Coil neg flying lead across the engine metal:
- If there are sparks, it suggests a fault downstream with amplifier, pickup coil etc. and yes I follow the next bit -
- If no sparks, its defo the coil or the supply voltage.
Now a Query, to eliminate the reluctor downstream of the amplifier, have you come across a definitive "on car" test for a faulty amplifier? Because it seems that this is the missing link in amplifier fault diagnosis.
honestjohntoo said:
Wedg1e said:
If you suspect the ignition amp and/or reluctor, lay a spare sparkplug on the plenum with its HT lead connected to the coil. Pull off the two-pin connector from the amp, switch ignition on and using a length of wire in the lead that goes to the '-' side of the coil, stroke it across your plenum and watch for fat sparks. If you don't get any now, either the coil is kaput or you have a serious lack of supply to it!
Ian, Did you mean "with the king lead HT connected"? But thats an interesting inverted diagnosis for the amplifier etc.So! If sparks are not present when cranking, say, then, when stroking the Coil neg flying lead across the engine metal:
- If there are sparks, it suggests a fault downstream with amplifier, pickup coil etc. and yes I follow the next bit -
- If no sparks, its defo the coil or the supply voltage.
Now a Query, to eliminate the reluctor downstream of the amplifier, have you come across a definitive "on car" test for a faulty amplifier? Because it seems that this is the missing link in amplifier fault diagnosis.
As to testing the ignition amp, when my pickup died what I did was...
Take distributor cap off.
Disconnect ECU trigger wire.
Disconnect coil '-' wire from amp.
Wire a 12v 21W bulb from amp to coil '+' supply.
Turn ignition on.
Flick distributor rotor back and forward against the vac advance springs. As the rotor triggers the pickup, the amp should flash the light. Brightness of the light proportional to your wrist technique
The 21W bulb acts as a fairly representative load.
Edited for tie poos.
Edited by Wedg1e on Monday 30th March 21:37
Wedg1e said:
Well, just connect a plug directly to the coil. If it won't fire with the '-' terminal earthed then if the coil itself is OK, my thoughts would be a high impedance on the 12v feed to it... ie a digital multmeter might say you have 12v as it presents so little load to it but under actual system conditions the 12v rail falls over.
GotchaWedg1e said:
As to testing the ignition amp, when my pickup died what I did was...
Take distributor cap off.
Disconnect ECU trigger wire.
Disconnect coil '-' wire from amp.
Wire a 12v 21W bulb from amp to coil '+' supply.
Turn ignition on.
Flick distributor rotor back and forward against the vac advance springs. As the rotor triggers the pickup, the amp should flash the light. Brightness of the light proportional to your wrist technique
The 21W bulb acts as a fairly representative load.
Got that too! thinks! if the reluctor/pickup coil is faulty then alternatively, perhaps a 1.5 volt pencell battery in series with a (say) 2700 ohm resistor touched to the input contacts of the amp would also induce a sparky response or with a lamp as you suggest.Take distributor cap off.
Disconnect ECU trigger wire.
Disconnect coil '-' wire from amp.
Wire a 12v 21W bulb from amp to coil '+' supply.
Turn ignition on.
Flick distributor rotor back and forward against the vac advance springs. As the rotor triggers the pickup, the amp should flash the light. Brightness of the light proportional to your wrist technique
The 21W bulb acts as a fairly representative load.
Indeed, a little test box containing all such bits, plus an activation switch would do it admirably, me thinks? Time for an experiment or two, prior to putting more stuff into an upcoming SD1 ignition manual/essay aimed at home enthusiasts (with acknowledgements as needed), Cheers
I sent another hour messing about with it tonight.
Tried taking the filter off and opening the AFM to listen for fuel pump, couldnt hear anything but not sure where/what i am listening for.
Put a bulb across teh injectors, saying that, I took the injector plugs off and poked the bulbs leads into the conntectors.
Now when i did it yesterday it was on the CSI, which flickers, and still does.
However on any of the other injectors NOTHING. Have I tested it right. I'm wondering if fuel in the cylinders if from CSI, but nothing from main injectors.
Immobilizer? How do they immobilize?
Sorry this is dragging on. I am having it towed to garage next week to look at it.
Tried taking the filter off and opening the AFM to listen for fuel pump, couldnt hear anything but not sure where/what i am listening for.
Put a bulb across teh injectors, saying that, I took the injector plugs off and poked the bulbs leads into the conntectors.
Now when i did it yesterday it was on the CSI, which flickers, and still does.
However on any of the other injectors NOTHING. Have I tested it right. I'm wondering if fuel in the cylinders if from CSI, but nothing from main injectors.
Immobilizer? How do they immobilize?
Sorry this is dragging on. I am having it towed to garage next week to look at it.
Tried taking the filter off and opening the AFM to listen for fuel pump, couldnt hear anything but not sure where/what i am listening for.
As i said, take the hose off the cold start injector place the end in a jam jar, turn the ignition to position 3, depress the air flap. This way you won't be guessing at a noise, you'll see the petrol rushing out.
Now when i did it yesterday it was on the CSI, which flickers, and still does.
However on any of the other injectors NOTHING. Have I tested it right. I'm wondering if fuel in the cylinders if from CSI, but nothing from main injectors.
If i remeber rightly the CSI is an independant circuit and operates from its own sensor. As for the rest of the injector, have you reconnected the bullet connector near the air flow meter that sends the crank pulse signal to the ecu?
Immobilizer? How do they immobilize?
On a wedge, most likely by cutting the power/signal to the coil or fuel pump. You can verify you have power to coil and pump while cranking easily with your test bulb.
As i said, take the hose off the cold start injector place the end in a jam jar, turn the ignition to position 3, depress the air flap. This way you won't be guessing at a noise, you'll see the petrol rushing out.
Now when i did it yesterday it was on the CSI, which flickers, and still does.
However on any of the other injectors NOTHING. Have I tested it right. I'm wondering if fuel in the cylinders if from CSI, but nothing from main injectors.
If i remeber rightly the CSI is an independant circuit and operates from its own sensor. As for the rest of the injector, have you reconnected the bullet connector near the air flow meter that sends the crank pulse signal to the ecu?
Immobilizer? How do they immobilize?
On a wedge, most likely by cutting the power/signal to the coil or fuel pump. You can verify you have power to coil and pump while cranking easily with your test bulb.
Edited by B-Reight on Tuesday 31st March 19:58
Edited by B-Reight on Tuesday 31st March 19:58
Bullet connector? I've not removed one. Is that the one with the inline resistor on? I'm not entirely sure where it is? There is a line from the amp that goes under the AFM and joins the trunking, which i assume goes to ECU, however no bullet connector on it.
Where is the fuel pump, im not sure.
Where is the fuel pump, im not sure.
Oh man...I really hope you get this sussed. In the Wedge Bible there is a non-start fault diagnosis guide as used by the factory and service bods. If you don't have a copy, let me know and I'll PDF a scanned image from the page.
When you get the car started - consider dumping the Efi or a Carb/mMllory set up and I promise you'll be amazed at the performance, ecconomy and reliability.
When you get the car started - consider dumping the Efi or a Carb/mMllory set up and I promise you'll be amazed at the performance, ecconomy and reliability.
Adam, Forgive me for being blunt, but its clear from the nature of your questions and your inabilty to follow some of the suggested solutions that you need to mug-up on the Efi system and possibly the Ignition system too.
There is a massive archive of material available, component descriptions, system analysis, laymens explanations, relatively easy-to-follow test processes, even a full blown efi ops manual, but until you decide whether to make the effort to do some basic reading, then the chances of ever getting to grips with your toy are pretty slim.
Remote analysis even by very well-informed forum members is already going nowhere because you cannot follow the suggestions, even worse do not know what the basic components are and where they can be found. Yet everything mentions is already written down, ad nausium
Do yourself a big favour and study some stuff.
http://www.vintagemodelairplane.com/pages/Rover_Te...
There is a massive archive of material available, component descriptions, system analysis, laymens explanations, relatively easy-to-follow test processes, even a full blown efi ops manual, but until you decide whether to make the effort to do some basic reading, then the chances of ever getting to grips with your toy are pretty slim.
Remote analysis even by very well-informed forum members is already going nowhere because you cannot follow the suggestions, even worse do not know what the basic components are and where they can be found. Yet everything mentions is already written down, ad nausium
Do yourself a big favour and study some stuff.
http://www.vintagemodelairplane.com/pages/Rover_Te...
frubes said:
Bullet connector? I've not removed one. Is that the one with the inline resistor on? I'm not entirely sure where it is? There is a line from the amp that goes under the AFM and joins the trunking, which i assume goes to ECU, however no bullet connector on it.Where is the fuel pump, im not sure.
When explaining cable connections it is normal to describe the colour.The connection from coil negative to pin 1 of the ECU is white with a black tracer and has a 6.8k ohm resistor in line with either bullets or spades, the resistor is normally located near the coil and AFM. similar to this
You can see the connection on the circuit diagram already posted on this thread.
If that connection is not complete the ECU cannot fire the injectors after cranking ceases
http://www.vintagemodelairplane.com/pages/Rover_Te...
Here is some basic reading material
http://www.vintagemodelairplane.com/pages/Download...
honestjohntoo said:
The connection from coil negative to pin 1 of the ECU is white with a black tracer and has a 6.8k ohm resistor in line with either bullets or spades, the resistor is normally located near the coil and AFM. similar to this
... or it may not have one at all. I know for a fact mine doesn't as I made up a new injection loom which was a copy (but shorter) than the original on the car, which had no resistor.honestjohntoo said:
Got that too! thinks! if the reluctor/pickup coil is faulty then alternatively, perhaps a 1.5 volt pencell battery in series with a (say) 2700 ohm resistor touched to the input contacts of the amp would also induce a sparky response or with a lamp as you suggest.
Hmmm, might have to rethink. According to my notes, when I had a 'scope on the output of the pickup coil and the distributor was spun by hand (off the engine, obviously) it measured 10v peak-to-peak. When spun using a cordless drill it hit 35v p-p! It's a very sharp pulse that goes negative first, followed by an almost vertical rise to the positive peak then a decay that matches the initial negative-edge, if you follow me. Scope was on 10mSec/div with 5V/div vertical to see it. Obviously this was off-load (ie ignition amp not connected).Gassing Station | Wedges | Top of Page | What's New | My Stuff