The V8 Owners Forum -

I have found that on a wasted spark system, my timing light doesn't work properly on cylinder 1 but works fine on cylinder 6 (it's paired cylinder)
I imagine it has something to do with the direction of current flow in the spark leads.
I believe the spark jumps from centre electrode to earth tag on one plug and from earth tag to the centre electrode on the other paired plug.

Correct me if I'm wrong

Regards Denis

DEVONMAN wrote:I have found that on a wasted spark system, my timing light doesn't work properly on cylinder 1 but works fine on cylinder 6 (it's paired cylinder)
I imagine it has something to do with the direction of current flow in the spark leads.
I believe the spark jumps from centre electrode to earth tag on one plug and from earth tag to the centre electrode on the other paired plug.

Correct me if I'm wrong

Regards Denis

Just turn/rotate the HT lead pick up around for the strobe gun on No 1 lead, and your thoughts are correct as to why

Played with both of mine when this first came up. The 'smart' one doesn't work on either. The dumb one works on both.

Tried turning the inductive pickup round on the smart one too. The dumb one has a direct connection to the plug terminal.

Eliot wrote:if you follow the instructions given above, the location of the vacuum can has nothing to do with the alignment. If the rotor is pointing to the post that connects to the spark plug in cylinder 1 when just before tdc for compression stroke of cylinder 1 - its timed correctly.

thats it eliot , thats what i ve done and firing order is correct ..1 8 4 3 6 5 7 2

Ive been through everything now .. rewired the dizzy to amp and rechecked and double checked .
Theres a huge spark , when i move the rotor arm with ignition on and hold the king from the coil to the earth its jumping about 2 inchs ... im not going to touch that !!:))

Right , its runs now but its well advanced about 2 inches before 12 BTDC ..
As soon as i move the dizzy to get the marks lined up .. its like the ignition is switched off..just stops dead and wont start unless i move the dizzy back again
With the strobe connected to lead 6 its exactly the same
The strobe light Dave is a just clip it on with no adjustments

So you have physically found TDC/compression on cylinder 1 and then ensured rotor arm phasing is pointing directly at the tower for cyl 1 ?


Anything that is marked on the front pulley is irrelevant for the above test.

stevieturbo wrote:

bodger wrote:
i know how to check if its at tdc and if its on compression stroke !

So do I...doesnt mean I've never done it wrong before...and before...and before lol

The symptoms do sound like rotor phasing is wrong, or as otherwise suggested rotating the dizzy is affecting wiring in some way interfering with the circuit.

ive done it wrong many a time ...lol
Ive checked everything twice and 3 times now ...
rewired the dizzy to the amp too ( got one of the aftermarket ones )

Sorry, wrong post

Have you perchance swapped over the two rotor arms

Are they identical?

Ian

Hi Bodger.
Is it possible that you mistakenly thing that No 1 cylinder is at the front of the engine on the drivers side (UK car).

This would explain your symptoms, because by advancing the dizzy by 40 ish degrees you would bring the correct No1 cylinder into line with the rotor and then the engine runs.

No1 is at the front of the engine on the left looking from the drivers seat assuming the engine is in the front of the car

Many in the past have been confused about which is the No1 cylinder,

Regards Denis

Hi
No all as shoud be in that respect .. no 1 on the right nearest the dizzy if you stand in front of the engine looking back

Im totally baffled now .. static timing is as should be ie: TDC ( PULLEY MARKS) = rotor arm pointing at no 1 plug lead ..

the dizzy is at that point so the vacumn unit is about half way between the water pump housing and thermostat housing ...so i get some movement in each direction ) !!

It just wont run like that ..i have rotate the dizzy anticlockwise so the vac unit is almost touching the waterpump housing so it will even run ..any attempt to move it clockwise is like switching the ignition off .. no spluttering , just dead stop ????

With the engine at TDC and the rotor arm pointing at No1 have you looked at the relationship between the VR sensor and its rotor? (you'll probably have to take the plastic cover off) Just clutching at straws.

And does TDC on the marker line up with true TDC? Given your apparent error, you'd not have to do this very accurately.

Dave , ive been out there all day again ...
Great minds and all that ..i looked at that and just couldnt make it out ..
It wasnt until i cut open an old dizzy cap and then i could see it ...
with the sensor lined up the rotor arm had already passed the cap pickup ...
Then i measured the vac unit arm .. they are 3mm differant in length , hence the relationship between cap and vr was not correct .. that would explain why it was so sensative to moving the dizzy
..
the batteries flat now though so cant try it

Just wondering if the trigger pickup line up , does that mean the rotor arm is directly in line with terminal on the cap ?

There's more than one version of this dizzy - the SD1 type has the vacuum unit in a different place to the RR one.

On the one I have here, the rotor arm lines up with a tooth on the reluctor ring. And is pointing at a cap contact when the tooth is in line with the VR sensor.

Left = Range Rover
Right = SD1

Chris.