No Spark
#1
Posted 28 February 2005 - 01:06 AM
so i decided to start 'er up, and nothing!
the starter turns and theres fuel (wet spark plugs)
but no sparks :sad:
I checked the voltage to the coil and its 12.4v
the points gap is within limits,
but they are a little pitted but overall in good condition
recently had new leads, cap, rotor arm, and battery
Is there anything else i can check?
Got a new coil on order and will probably get some new points
Mini is an 84 mayfair (with different engine)
Still 998cc with HS4
Its kinda rendering me Stage 1 kit (thats on order) useless as the car wont start.
#2
Posted 28 February 2005 - 01:39 AM
Where and when are you measuring the voltage at the coil? If you're measuring between coil (+) and chassis ground with the ignition on, this is OK. If you are measuring between coil (-) and chassis ground... the coil has power and the points are open... that's all it indicates.
1) Start by checking for spark at each plug. Pull each plug individually and clamp/rest it on the block such that it has a good ground. Have an assistant crank the engine while you watch the plug(s) for spark. If you have spark this way, check your static timing and make sure your problem isn't really flooding of the carbs.
2) If no spark in the test above, pull one plug and clamp it to chassis ground. Pull the center wire from the dizzy cap and connect it to the test spark plug you clamped to ground. (This way the coil fires one test spark plug... eliminating the dizzy cap and rotor from the equation). Remove the dizzy cap and turn the engine over until you see the points are open. Switch on the ignition. Use a screwdriver to short the two halves of the points together (repeatedly and quickly) while you watch the test spark plug for sparks.
3) If no spark with the screwdriver, pull the low-tension wire off the coil (-) terminal (the wire between the dizzy and the coil) and place a jumper wire on the coil (-) terminal. With the ignition on, tap this jumper wire to chassis ground (tap... not hold). If you do not see a spark on your test spark plug, suspect the coil. If you see a spark, go back to the dizzy.
4) If test #3 gave you a spark, reconnect the wire between the dizzy and the coil (-) terminal. Look for a short holding the points at ground potential. The points have to open and close... making and breaking a path to ground for the coil power. If no obvious problems are seen, remove the condenser and repeat the screwdriver test. IF this still gives no spark, look very hard for a something shorting out the points to ground. If removing the condenser gave you a spark, install a new condenser.
This is a succinct explanation of what's supposed to happen:
The ignition coil is fundamentally a transformer. Since it is part of a DC circuit it only produces current on the "secondary" or high-tension windings when the DC current flowing through the primary windings is switch "off". With the ignition switch on and the points closed, current flows through the coil creating a magnetic field in the coil primary windings. When you crank the engine, lobes on the dizzy cam rotate causing the points (which are effectively a switch) to open. When the points open, the magnetic field in the primary windings of the coil collapses producing a sudden, massive voltage to be generated in the secondary coil windings. The condenser is wired in parallel to the points to absorb a voltage spike on the primary windings as the magnetic field collapses. The voltage generated in the secondary windings is routed via the coil center post to the center of the dizzy cap. With proper timing, the rotor inside the dizzy cap directs this energy to a spark plug post/wire and subsequently one of the spark plugs.
If the points never close, if the points fail to open, if the points are shorted to chassis ground, or if the condenser is internally shorted, the primary windings effectively do not "switch" and no voltage is generated on the secondary windings.
#3
Posted 03 March 2005 - 01:25 PM
i have been abit busy.
i did try test 1, 2 and they both gave no spark,
i ordered a new coil on sunday, and supposed to be 24 hr delivery,
but its still not here, (i rang up and they said it will be going out today!!!)
i will try 3, 4 soon (probably after lunch) and get back to you
#4
Posted 03 March 2005 - 04:09 PM
You can test coil by pulling the lead from centre of dizzy, put a spark plug in it and test as normal.
If you get a spark.....then its the dizzy. If not, it could be coil or the wiring.....
#5
Posted 03 March 2005 - 04:46 PM
#6
Posted 03 March 2005 - 05:04 PM
On my "low-tension wire" there is a jumper in the middle anyway,pull the low-tension wire off the coil (-) terminal (the wire between the dizzy and the coil) and place a jumper wire on the coil (-) terminal. With the ignition on, tap this jumper wire to chassis ground (tap... not hold). If you do not see a spark on your test spark plug, suspect the coil. If you see a spark, go back to the dizzy.
so i disconnected that and put a spark plug on the end of the coil-diss HT lead,
put the ignition on and tapped the LT coil-diss wire.
LT wire sparked, but HT sparkplug didnt do anything.
Does this mean its the coil?
#7
Posted 03 March 2005 - 06:21 PM
#8
Posted 03 March 2005 - 06:41 PM
#9
Posted 06 March 2005 - 12:43 AM
"Sorry but we are currently out of coils, so one will be sent when they are instock"
so ill have to wait till it arrives.
#10
Posted 06 March 2005 - 03:15 PM
Go to your local car parts store and tell them what car the coil came out of and have them recommend a suitable replacement. The only question to selecting the right coil is whether or not it is designed for use with "ballasted" ignitions... and whether your car has this type of ignition. (Assuming you have a stock ignition system).
If your coil (+) terminal is fed by a "pink" wire, it's likely a ballasted ignition system and you need a ballast ignition coil (about 1.5 ohm). If your coil is fed by a "white" wire, its likely a standard ignition and needs a 3 ohm coil. There is no reason you need to wait with a car that won't start until someone makes/buys/delivers coils to your source. There will not be anything unique or special that forces you to use a Rover/Unipart replacement.
#11
Posted 07 March 2005 - 11:27 AM
I oredered
a HS4 Carb service/rebuild kit,
stage 1 kit for HS Carb,
Sports Coil.
The service kit had the wrong Jet in it (mines a Waxstat?)
and i only realised this when i saw it was different (but they had nothing about this on the website!!!! so how was i to know :sad: ).
The stage 1 kit they sent was for a HS6 Carb!?!?!?! so the K&N Filter doesnt fit.
the exhaust y piece is a very tight fit (probly just the car) and the link pipe goes in the Y piece and in the box but its such a tight fit because the Y piece doesnt have slots in it (easily added),
and im guessing the the Carb Needle is wrong for it,
i think the red spring is right though isn't it?.
and of course they didnt send a Coil, so overall its pretty C**p £200!!
So Im going to ring today and complain!!
They also messed up with my brothers wheels, by putting the wrong picture on the wheels, so my brother wants the ones in the picture, so when he orders them he gets the wrong ones!!!!
Who are they I hear you say?
Anyone else had problems with them??
I think ill be avoiding them from now on.
#12
Posted 07 March 2005 - 12:15 PM
#13
Posted 07 March 2005 - 01:34 PM
#14
Posted 07 March 2005 - 08:16 PM
But there you go, that's just my experience of them. It was all a few years ago now but you'll notice there's more than one person on here who refers to them as the 'nasty people in Byfleet'
#15
Posted 07 March 2005 - 09:48 PM
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