Running issues!!

Hi All,

A bit of a return from the wilderness for me.

After a few years away from the forum due to child, work, life etc., I come with cap in hand looking for advice.

A quick refresher: Neil's the name, living in Australia, driving a 1976 P6B. The car is a daily, reliable runner and never lets me down................. until now!!!

Car was running relatively fine but due for a service. When I checked the points they were so badly burned out that there was nothing left of the contacts!! Despite this the car was still starting and stopping and everything in between.

Decided to fit electronic ignition system instead of points.

The car then ran like a bag of bolts. Horrible idle, no power, stalling etc.

Since then I have checked timing, replaced plugs/leads/coil, had the carbs off (cleaned/checked/reset), tried another set of carbs and still can't get the car to run right!

What could I be missing?

Next step is the fuel pump (a few years old but I think it's OK).

All suggestions gratefully accepted.

RT.
 
Can't give you much tech advice as it's not my strength, but from what I have gathered in the past I'd recommend you to search 'Ballast resist(or)' in the Electrics section of the Forum. Quite a lot of similar issues.
Best of luck
John
 
Is your advance diaphragm ok? I'm having a similar problem which I think I've narrowed down to the diaphragm. Will find out soon as I'm just going to get the whole dizzy rebuilt.
 
Hi Rob,

From what I have been led to believe the vacuum advance becomes redundant with the electronic ignition.

I do stand to be corrected though.

RT.
 
Hi again,

Thanks for the replies.

The 12v supply is from the coil.

RT.
I believe the V8 has a ballasted coil, if the ballast is still in place there wont be 12v at the coil with the engine running, check it with a meter. You may need to get a 12v supply for the electronic ignition from another source.
 
The ballast resistor is usually a length of resistance wire in the loom.

You should still run vacuum advance with electronic ignition. If it’s one of those modules that replaces the points inside the original distributor, the vacuum advance should be connected as before. The electronic module doesn’t control the ignition timing, it just replaces the points as the trigger for firing the coil. The timing is still controlled by the original weights and springs, and vacuum diaphragm.
 
if you have ftried everything else, my guess would be the advance mech in the dizzy is shot, that can create all sorts of running problems which can come and go. it could be worth putting a timing light on it and look to see how the dizzy advances the timing with revs, ive found many a car with a erratic timing advance
 
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Hi again,

Have checked timing again and it looks good. Sparking on all cylinders.
Tried the original cleaned carbs and now worse than ever.
Backfiring through carbs and exhaust, zero power, no idle/running without choke.

What could have changed so radically??

RT.
 
If the real running problems started after you fitted the electronic ignition, then that's where I'd be looking for the cause of it.
 
Have you checked what roverp480 asked? Does your electronic ignition need a 12V coil? If so, are you using a 12V coil?

Try running the ignition from a different source, e.g. the windscreen washer motor.

Richard
 
Did you remove the plug leads as part of fitting the electronic ignition, are they in the right order?
 
Did you set the timing as per the book?

One of the electronic units I retrofitted need to be set a few degrees more advanced than standard points.
 
backfiring through carbs is typical of timing incorrect.. some electronic. dizzy's can be mapped and don't need vacuum advance unit .replaced my dizzy with electronic unit which retains vacuum advance unit. if diaphragm isn't working wont give backfiring via carbs. ( crap acceleration ..yes) if we have strobe? do check base timing and spark advance. I would check all basics. plugs correct? timing is on compression stroke no1 cylinder. etc do check voltage issues 12V ? ballast and coil. I fitted new high performance coil.plugs .ht leads .cap. arm as well as refurbished carbs. so far its reliable . poor idle when cold ..not exactly rubber burning capability even though a V8.
 
Hi again,

Have got everything together for a more extensive refresh of my ignition and fuel systems.

New electronic distributor (ex: SimonBBC).
New Lucas 17ACR 45amp. alternator.
Fully rebuilt, rebushed carbs.


Before I start the fitting I have two questions:

The new alternator comes with a slightly smaller pulley. Is it essential to change the pulleys over??

Is there an ABC type "Idiot's Guide" to bypassing the Ballast Resistor wire?? (Eg.: A/Wake up. B/Put trousers on. C/Bypass Ballast Resistor.)

All assistance greatly appreciated.

Regards RT.
 
The new alternator comes with a slightly smaller pulley. Is it essential to change the pulleys over??

The smaller pulley will allow the alternator to spin faster for the same engine rpm. In slow traffic with headlights on, this is not a bad thing as the higher rpm will reduce the chance of seeing a discharge. Same at idle, the discharge won't be as great, all things being equal when running a slightly smaller pulley compared to a larger one. As for bypassing the ballast resistor, I have yet to need this excitement :p, so I will leave the answer to one of our friends with experience of the procedure.

Ron.
 
I found that the junction between ballast wire and normal wire was deep in the loom, behind the passenger glove box. Rather than cut in that awkward place I just took a new line from the ignition switch to the coil. Your experience may vary. I'm also thinking I might put the coil on a relay to reduce amperage through the ignition switch...but I don't know if that's overkill....
 
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