24 replies to this topic

[LC-GTR-1969]

Gday everyone,

 

I've got this crazy ignition timing issue...

 

I have crane cams HI6 ignition box with LX-92 coil, bosch HEI dizzy... 202 holden.

 

The dizzy is locked.

 

The car was running fine... I was cruising home the other day and the car started running like crap... Farting through the carbs and back-firing. This progressively got worse, then started to actually get better. The car was surging and carying on... then would clean itself up and run like it has really advanced ignition (would idle great but was detonating).

 

No changes had been made prior to the engine doing this- it just developed on its own accord haha...

 

I subbed a brand new coil as this was initially suspected, and still the same.

 

I checked the ignition timing and to my horror the engine has a mind of its own- I check the timing and it was 10 degrees BTDC- engine will hardly idle, I give the engine a little rev to help stop it stall, and i am still watching the light... Engine now idles at 1500rpm, running smooth but timing is at 40degrees BTDC??? WTF???... I give the engine a little rev again and the timming changes again to 30" BTDC once the engine 'settles' back to an idle.

 

I have confirmed the balancer has not spun- have checked.

 

I have pulled the dizzy and I have confirmed the dizzy is still locked. The dizzy drive gear is in great condition- no issue there.

 

I am suspecting the HI6 ignition module, but these are expensive to just buy and replace if it is not the cause... I would like some ideas and thoughts before I bite the bullet and just end up replacing everything lol...

 

ANy ideas?

Edited by LC-GTR-1969, 01 March 2015 - 10:49 AM.

[S pack]

Can you disconnect the HI6 ignition module and see how see runs?

[LC-GTR-1969]

Can you disconnect the HI6 ignition module and see how see runs?

I could if i had another module to substitute, however I don't unfortunately... Unplug it and no spark...

[S pack]

I could if i had another module to substitute, however I don't unfortunately... Unplug it and no spark...

Ah ok, the HI6 module replaces the original Bosch module rather than working in conjunction with it.

 

AFAIK when HEI ignition modules play up they usually just stop working.

[LC-GTR-1969]

Do you think I could have a broken camshaft retainer? I am thinking that if the retainer is broken, the cam could have excessive end-float and I figure 2-3mm of movement in the cam could equate to about 30 degrees of swivel at the dizzy- which may explain the wierd fluctuations in timing...

 

Is this plausible?

[Litre8]

I can't believe I am saying this but I agree with Bomber..  

[LC-GTR-1969]

I can't believe I am saying this but I agree with Bomber..  

Ok, good point... 

 

I will buy a cheap points dizzy and see whats happening... Anyone got one lying around that they want to pass on?

[LC-GTR-1969]

You could stick a small prybar or large flat screwdriver through the dissy hole and pry against the sides of the dissy drive gear on the cam to check for movement. Or get someone to rock the crank back and forth while you watch or feel the cam through the dissy hole.

 

Thats a good idea also...

 

2 things to check...

 

1) I will check end-float of cam with screwdriver or pry gear (have done this with cranks plenty of times).

 

2) If the cam works out ok, I will pick up a points dizzy and test.

 

Thanks again these are great ideas...

[LC-GTR-1969]

Ok, so I have pryed the cam gear to check for end-float, and this does not appear to be the issue... so my hypothesis is de-bunked hahaha

 

So i am back to subbing a points dizzy to help isolate. I will report back when I find it, if i find it...

[LC-GTR-1969]

Something else that comes to mind: check that the stator in the dissy is firmly anchored. If you don't run a vac advance unit make sure the stator is secured and if you do run vac advance check that nothing's broken or sticking.

Thanks again for the reply...

 

I dont run the vac advance, but the mechanism is in tact...

 

The stator turns equivelent to a normal functioning vac advance- my vac nozzle is fused closed but the mechanism is in tact.

 

The strange thing is, however, that the spark is retarding aboutt 20 degrees as well as advancing about 20 degrees from where it should be (20 degrees both way from 27 degrees, where the timing should be...)

 

How do I lock the vacuum advance to further isolate?

[LC-GTR-1969]

And is the inner stator that's fixed to the shaft still fixed to the shaft?

Saw a ford dizzy do this once....

 

It appear to be- I checked it and it felt firm but I will check it again (I have checked so many things that I am starting to forget what I have done and haven't done hahaha)...

[LC-GTR-1969]

And is the inner stator that's fixed to the shaft still fixed to the shaft?

Saw a ford dizzy do this once....

Ok- I just got home and had a closer look at this... When I first checked I used a little pressure and it seemed ok...

 

I just gave the reluctor a little more pressure to see if it would turn on the shaft and low and behold, the reluctor is in fact turning on the shaft, which explains the ignition issue. It just needed a smidgen more pressure and it turned (and obvoiusly when the engine is revevd the centrifugal force causes this to move on its shaft and cause the timing to wander).

 

Thanks for all the advice and help. Now time to either fix dizzy of find new one...

 

Cheers

[LC-GTR-1969]

Twas OJ's post that jogged my memory....

 

Went out to a mates place ages ago after he picked up this stonking great big 45 series ute with a 351 in it, typical somewhat country town hick shit you see around here all the time, they couldnt get it to run worth a damb but alas had no timing light....They decided a timing light would be a good idea after frOcking around with the carb over a few cartons with a cordless and a jet drill whilst randomly playing spin the dizzy mind you....

 

Half hour of frOcking around and no sence, similar to what you describe, get it set, set the carb, get it good, give it a rev and out of wack. 

Dizzy cap off and another 15 minutes frOcking aroudn to notice the stator floating merrily around doing its own thing.......Problem isolated haha. 

 

Cheers. 

Yes, sounds very familiar... lol

 

Does anyone know if the VK EFI reluctor is the same as the 'normal' bosch holden 6 electronic distributor? 

 

I have pulled apart my dizzy and the reluctor tooth that normally locks the reluctor to the shaft has sheared, so I figure I just need a replacement reluctor... I can get my hands on a cheap VK EFI dizzy and was wondering if the reluctors are intechangable? I know the weights and advance are different stock but that wont affect me...

[S pack]

My Ellery's VB - VK shop manual doesn't mention or show a different dizzy for the EFI engine.

The shop manual shows the pulse generator disc (what you call a reluctor) is located to the dizzy shaft by a small roll pin. The dizzy shaft and the pulse disc have matching grooves for the roll pin.

[rodomo]

the injected version had a normal dissy.

Best dizzy for a hotty, the springs are stronger, just have to modify for maximum advance.

[LC-GTR-1969]

No idea. 

honestly if you ask around you sholud be able to get your hands on a free electric dizzy to nab parts from.....Hell i'll post you one if you get stuck. 

 

Cheers. 

Thanks for the offer Bomber but its all good- I have made a keyway and a new key to pin the original reluctor in place, which I think should work. 

 

Thanks again for all the advice... much appreciated.

Edited by LC-GTR-1969, 03 March 2015 - 12:20 PM.