urgent...HT lead lay out required.

martin hughes · Post by **martin hughes** » Thu Jun 08, 2006 9:23 pm

Hi, Still having problems with not starting once warm so changed the distributor cap, rotor arm and leads today. At first i changed the leads like for like as I took them out, but when I started up it misfired. So I re did them as it says in the manual, but now it won't go at all!!

Can anyone tell me the correct order for the leads. My wife and I have checked and rechecked against the manual so it's no an error on our part, for a change!

Please help before the wife calls the local scrap man!!

jonnyboy · Post by **jonnyboy** » Fri Jun 09, 2006 12:22 pm

Does this help

martin hughes · Post by **martin hughes** » Fri Jun 09, 2006 12:38 pm

brill!
wired up as shown but still no start!
changed plugs and coil at first due to it not starting when hot, still no joy.
then changed rotor, leads, and cap and will not start at all.
stripped and referbished carbs this morning still no joy.
spark looks a bit poor and weak.

any ideas?

ERC4558 · Post by **ERC4558** » Sat Jun 10, 2006 1:04 am

Hi Martin,
it may be worth going back to your original rotor arm and dizzy cap with the original lead configuration and see if it will start then. If it does then swap the items one at a time to fond out whats wrong. If your leads didn't follow the correct firing order it might be worth checking that the distributor shaft was positioned correctly when the distributor was inserted
as it sounds as though it may not have been.

foggydave · Post by **foggydave** » Sat Jun 10, 2006 4:40 am

I changed caps a few months ago and found the rotor arm was .5 mm too short, this gave the same symptoms as you have.
I have also had problems when the vacuum advance/retard lever has not located in the distributor base plate properly.
Have you ensured that the rotor arm is pointing to the correct cylinder lead when the piston is TDC it is sometimes difficult when fitting a dizzy to allow for the correct twist when locating it in the drive shaft, the previous owner may have wired up the leads to suit whichever position the dizzy ended up in when it was fitted.

Have you tried changing the dizzy back to points to see if the electronic ignition system is at fault ie the power module or the dizzy componants.
I have a spare lumenition power module if you think it may be that if you want to borrow it.

Bumpkin · Post by **Bumpkin** » Sat Jun 10, 2006 1:13 pm

Right try this.
On the right (Looking in) inner wing is a small rectifier thingey.1 wire is for a starting voltage the other is for a running voltage. 12 & 9 respecivly i believe.Does the vehicle appear to want to run but as soon as u let the key go she stops. This is how i found out. I swapped the wires around. This might help.
Tel
Johnney. Very GOOD diagram!!

martin hughes · Post by **martin hughes** » Sat Jun 10, 2006 8:04 pm

Hi, Thanks for all the advice! I removed the left hand side rocker cover today and positioned engine at no1 top dead centre, removed the dizzy cap to find rotor arm pointing to the next spark plug position. Moved every lead one space around the cap. The engine now starts!! BUT is still misfiring and not enough power to move. Gonna drop it off at the local garage on mon to get timing checked unless any one has any ideas which don't involve forking out large sums if money!
Thanks Again.

foggydave · Post by **foggydave** » Sun Jun 11, 2006 6:08 am

So hopefully a good timing session should sort things

Bumpkin You describe bypassing the ballast resistor which is ok in the short term but if you are running a ballasted coil will cause it to overheat and eventually break down

ERC4558 · Post by **ERC4558** » Sun Jun 11, 2006 8:25 pm

Hi Martin,
I would still try the old cap and rotor arm (if you still have them) first to see if the mis-firing stops. You don't sound too far away from a solution yourself so it'd be a pity to start spending money!. I would then move the rotor arm position to the correct location with no 1 cyl at tdc on firing stroke then swap your leads accordinglyand do a static timing check to get you away.

martin hughes · Post by **martin hughes** » Sun Jun 11, 2006 8:41 pm

hi,
did the number 1 top dead centre thing today and reset the distributor as per the book.
engine now runs as sweet as a nut but still fails to start when hot any more ideas? have worked through all other sugestions so far.

Many thanks.

foggydave · Post by **foggydave** » Mon Jun 12, 2006 6:06 am

Question
What part in the ignition system does the starter motor play if any ie does the solenoid provide a circuit of some sort to the coil/distributer when the ignition key is turned. There is a wire going from the solenoid to the ballast resistor.

The reason I ask is that if you put "V8 hot start problems" into Google a lot of people talk about the proximity of the exhaust downpipes especially tubular ones to the starter motor solenoid, also the lack of a heat shield between the starter motor and the exhaust down pipes.

Just a thought because its starting not running thats the problem so if the main ignition system ie coil/leads/plugs etc keep the motor running sweetly when it is going, then the problem would seem to be with the initial start which is were the starter solenoid plays a part .................................... maybe

or are we clutching at straws here??????

Martin I will ring later today re module.

ERC4558 · Post by **ERC4558** » Mon Jun 12, 2006 1:32 pm

Hi Martin,
Do the check of the spark when cold against the check when hot and no start, if theres a diffrence we'll continue down the ignition route. If theres no diffrence try pulling the choke out and pumping the throttle (when it wont start hot) then as quickly as you can get the easiest plug out of the head as fast as you can. Have a look at it and it should be soaking wet, if not the problem with the petrol starting is a vapour lock and once thats sorted we can have a look at why it wont start on gas either.

martin hughes · Post by **martin hughes** » Mon Jun 12, 2006 8:07 pm

Checked some items tonight with engine running,
unfortunatly could not get it to not start!
not quite as warm tonight.

spark length running 13mm
spark length starting 4mm

coil voltage at 950 rpm (+ to -) 4.8 to 5.1 volts
coil voltage at 950 rpm (+ to earth) 11.14 volts

coil voltage at starting (+ to -) 3.5 volts
coil voltage at starting (+ to earth) 7.5 volts

coil voltage ignition on (+ to -) 7.5 volts
coil voltage ignition on (+ to earth) 9.0 volts

white and purple wire from starter motor is not going live on start up!

luminition box is wired to the live on the fuse box (feeding coil as it should with ignition on through balast resistor)

will try to bypass the ballast as suggested next time it fails.

also arranged to borrow the luminition box off foggydave.

foggydave · Post by **foggydave** » Tue Jun 13, 2006 5:23 am

You could try using a hot air gun ie the ones used for paint stripping and warming each componant individually until you find which one is causing the problem.

ps module posted Monday.

ERC4558 · Post by **ERC4558** » Tue Jun 13, 2006 8:49 am

Hi Martin,
Is the wire from the starter the one which gives a straight feed through to the coil (as opposed via the ballast resistor) if so tht will almost certainly be part of your problem also if the starter is tired it will be drawing more current than it should which would give you an even bigger volt drop during starting.