Duncan Mould
|
| posted on 29/12/07 at 09:18 PM |
|
|
X flow ignition problems
I wonder if anyone can help me.
I have recently purchased an old Dutton Phaeton with a lovely rebuilt engine and a right squirells nest of wires. So i thought dont panic its points
and condenser it only needs 12v to the coil+ and then the -side of the coil to the points. simple? only I am getting nothing to the points, I have
tried 2 new condensors (intermotor and Bosch) and still no spark accross the points. I have a feed of 12v before the condensor but nothing
afterwards.Can anyone shed any light on this subject. Many thanks Duncan
|
|
|
|
|
mookaloid
|
| posted on 29/12/07 at 09:29 PM |
|
|
Often the feed to the points is earthed out before the power gets there. This is usually due to incorrect assembly of the points (a missing plastic
insulating washer) or the wire to the points is defective in some way.
Cheers
mark
"That thing you're thinking - it wont be that."
|
|
|
Duncan Mould
|
| posted on 29/12/07 at 10:05 PM |
|
|
where does the washer go?
The condensor is earthed through the baseplate? correct, then the wire from the condensor is screwed down to the points body? correct. Its so simple
why wont it work.
|
|
|
dave-69isit
|
| posted on 30/12/07 at 01:36 AM |
|
|
how old is the loom setup some set ups have a 9 volt coil with a ballast risister in line and 12 volts could burn the condenser out straght away
|
|
|
Dusty
|
| posted on 30/12/07 at 02:32 AM |
|
|
Wire from (to) condenser and the coil negative go to the moving arm of the points which should be insulated from the fixed arm. The points act as a
simple on/off switch in the earthing side of the coil. Going open circuit (points opening) collapses the coil primary field and generates the HT pulse
in the secondary wirings. Although you do often see a small LT spark across the points as they open, the condenser is there to reduce/prevent this.
Assuming the circuit is correct, no spark means no switching (constant open or closed circuit) or switching but no response (duff coil).
|
|
|
rusty nuts
|
| posted on 30/12/07 at 10:57 AM |
|
|
Little tip with Motorcraft distributors is to bi pass the little black box (if fitted ) on the side of the distributor body and to make up and fit a
small earth lead between the points securing screw and the baseplate to distributor body screw. This will improve the voltage drop across the points
giving a stronger spark. Have you tried disconnecting the neg lead from the coil and testing voltage? If so then test at the points end of the L.T.
wire with the wire disconnected. New points may need cleaning , just put a piece of clean paper between contacts and wipe a few times. Have you set
the points gap? may seem obvious but worth checking.
|
|
|
rusty nuts
|
| posted on 30/12/07 at 11:02 AM |
|
|
Might be worth converting to a Valencia electronic set up at some stage. More reliable with very little maintanence.
|
|
|
02GF74
|
| posted on 3/1/08 at 11:46 AM |
|
|
have you fixed it?
wiring is as follows:
12 v --- coil + ---- coil - ---- point ---- point ---- 0 V
---------------------------------|---- condenser -------|
so the two points are shorting col - to 0 V.
If you are measuing voltage at coil - and the points are closed or the condenser is short circuited, you will see 0v.
trun engine (put in gear and push) so that points are open (I think you can push them open with screw driver) then you should see 12 V at the coil
-.
If you don't have DVM, andthere is no excuse as maplins sell them for a fiver, then fitting a bulb across the points you will see it light up
when points are open and off when closed.
If ballast resistor is fitted, then you would see 9 V instead of 12 V.
Have you check the coil is working? measure resistance between + and - (with wires removed) - should be 3 ohm or 1.5 ohm, latter being for used with
ballast. If open circuit, then coil is duff and you aint' ever gonna see any volts on the points. Likewise if condenser is shorted - unlikely
since they are self-healing but remove it to take it out of the equation.
[Edited on 3/1/08 by 02GF74]
|
|
|
.jpg)
