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Rover V8 ignition problems
Alez - 30/6/08 at 12:25 PM

Hi All,

Engine starts but it's all missfire and hesitation, just runs at the moment. It has a Mallory distributor (points) but, given that I have to fix it anyway, I'm thinking going electronic so that less maintainance is required in the future.

My problem is I'm not sure what part numbers I need to order, partly because I don't know what I currently have.

The engine spec is as follows: 4.6 Cross Bolted Rover V8 | Vulcan Maxiflow gas flowed big valve heads | Piper 285 Cam | High Rev lifters | Steel timing gear | Mallory distributor | Webber 500 | port matched Offenhauser inlet | Edelbrock full engine dress kit.

Looking here:
http://www.rimmerbros.co.uk/rimmer/rover/v8engine/ignition
I think maybe what I currently have is the so called "RB7459":
http://www.rimmerbros.co.uk/cgi-bin/rimmer?findpart&PartID=RB7459&Page=rover/v8engine/ignition
And what I'm looking for would be the "electronic RB7459":
http://www.rimmerbros.co.uk/cgi-bin/rimmer?findpart&PartID=RB7459ELECTRONIC&Page=rover/v8engine/ignition

I would appreciate confirmation of that or any comments because it's an expensive item and I'd rather get this right first time as I'm far away as well and shipping costs are a little high.

I attach a pic of the distributor, where you can see the high tension coil and capacitor (attached to the distributor).

Thanks everyone.

[Edited on 30/6/08 by Alez] Rescued attachment fury_ignition.jpg
Rescued attachment fury_ignition.jpg


Alez - 30/6/08 at 12:42 PM

Attached is a picture of the original ignition as far as I was told when I bought the car.. Rescued attachment fury_ignition_original.jpg
Rescued attachment fury_ignition_original.jpg


Alez - 30/6/08 at 12:47 PM

There's a "performance" Lumenition electronic ignition which is significantly cheaper but I don't know if that suits my engine:
http://www.rimmerbros.co.uk/cgi-bin/rimmer?findpart&PartID=RB7323PERFORMANCE&Page=rover/v8engine/ignition


02GF74 - 30/6/08 at 12:49 PM

firstly the mallory dual point distributor, wot yours looks like, is meant to be the biz so don;t start chucking money on kucase ones.

the ignition system comprises the following:

* spark plugs
* HT leads
* coil
* distributor (points, arm, cap, capacitor ...
* possibly basllast resistor
* battery, wires and earth strap

so there are quite a few places that can go wrong causing problems.

other factors are tune of engine, timing, petrol, spark plug rating and gapping, routing of HT leads etc.

firstly has it always done this?
if not, when did it start and what was the last thing changed?

meanwile something to try.
1. check timing
2. check routing of leads - see haynes manual aout the crossover of leads
3. check cap for tracking
4. check rotor arm
5. can you isolate missing to one or more cylinders (remnove leads and see if problem gets worse or stays the same).
6. check plugs7, is coild breaking down
7. is coil correct one - should be 3 ohm promary resistance
8. does problem start immediately or after engine has warmed up

etc etc ....


ah, you posted whilst I was typing - other thing to try is to fit your oringinal distributor and see what happens, 10 minute job,

[Edited on 30/6/08 by 02GF74]


Alez - 30/6/08 at 01:02 PM

Thanks a lot.

The distributor is in fact the dual point one, I've been told this a couple times.

The spark plugs have been replaced very recently and that fixed a little misfire I used to have. The car has been running smoothly since then until very recently. This fault hasn't happened before and it's a sudden one (it hasn't appeared gradually): the other day I started the engine and the problem showed immediately. I've started the engine a couple more times since then and nothing has changed, same severe problem still there.

Thanks for the tips, I'll see what I can make of that with my very little hands on knowledge.


theconrodkid - 30/6/08 at 01:13 PM

could be condenser,see if points are burnt,also move the coil,they dont like getting too hot


David Jenkins - 30/6/08 at 01:17 PM

If you can get hold of a Ford EDIS-8 module and coil(s), I'd recommend changing to Megajolt.

Note: I put 'coil(s)' because I suspect that it uses 2 separate 4-wire coils...


hughpinder - 30/6/08 at 02:13 PM

If its running that badly I wouldnt have thought it was anything to do with a single cylinder.

Apart from the things mentioned it could be a collapsed cat matrix (if you've got a cat) or problem with the vacuum advance?

Regards
Hugh


wilkingj - 30/6/08 at 02:15 PM

Nothing wrong with a properly set up Mallory.

Check the coil is a 12V coil if you Dont have a ballast resistor.
Or That its 8Volt (or marked for use with a ballast resistor).

Dont use a Ballasted coil without the resistor (there are more than one resistor value, so get the right one for your coil).
Dont use a 12volt coil With a ballast resistor.

If you use a Ballast resistor, you will need to feed 12V direct to the coil whilst cranking the engine. (I used a relay on the Starter circuit to short out the resistor with the contacts).

I agree with check the capacitor (Condenser for you Auto electricians).
Check the points and their gaps.
Check the Dizzy spindle for sideways movement / wear.
Check the advance and retard action is smooth. Check the Vacuum advance (if you have one).

Check for air leaks in the manifold, and connectors. (Brake Servo Air Pipe blocked off properly?)

I would NOT go and put a Std Rover Dizzy on it, if I had a Mallory in my grubby hands. Its a backwards step, unless its faulty. Then I would fix it.

Keep working on it. you will get there, and its probably something stupid.

Oh.. Check the timing mark on the crank pulley is actually Correctly aligned. ie TDC is really when the piston is at TDC. They can be miles out!. check with a long rod (so you cant loose it inside and have to strip the head off to extract it) down No1 cylinder, and turn engine by HAND ONLY. Rocker box off so you can see both valves are closed.

Keep at it mate there is plenty of helpers on here for you to use.


EDIT:
Where is the capacitor connected to? Is it across the points to ground?
It should be on the LT side of the points and earthed to the chassis / casing (like you have).

If you have the capacitor wired to the wrong side of the points, it will give interesting results.
Just a thought, as its an externally mounted capacitor. I take it, its the corerct one for a set of points, and NOT one for radio supression. usually the capacitor is inside the Dizzy. not being familiar with the mallory dual pointer, is there a capacitor inside as well?
And as its a Dual pointer, should there be two Capacitors? (Dont know about this bit on a Mallory)

I would google Mallory's web pages as they have some very good support stuff on there.


[Edited on 30/6/2008 by wilkingj]


robinj66 - 30/6/08 at 03:43 PM

You are correct - your present dizzy is the dual points Mallory. They are great when they are working but seem to require regular adjustment. I would check the gaps on both sets of points as they do close up and tend to give the sort of symptoms you are describing.

the upgrade for the Mallory is the Unalite which involves replacving the troublesome dual points system for a new rotor and pickup. (Check around for prices as you may be able to get it cheaper than RPi)

Your original dizzy looks like a Lucas DLM8 - It should have the model stamped into the dizzy body just below the cap. the weak point in that system is the electronic box (amp) which tended to suffer from vibration, heat etc.

That amp unit can be replaced quite cheaply - have a look here http://www.v8forum.co.uk/forum/viewtopic.php?t=78
and elsewhere on that forum for more info.


PS one other thought - Mallory distributors do like to run with the Mallory supplied coil. Not sure if the one in your top picture is actually a Mallory one

[Edited on 30/6/08 by robinj66]


Agriv8 - 30/6/08 at 04:42 PM

quote:
Originally posted by robinj66
You are correct - your present dizzy is the dual points Mallory. They are great when they are working but seem to require regular adjustment. I would check the gaps on both sets of points as they do close up and tend to give the sort of symptoms you are describing.

the upgrade for the Mallory is the Unalite which involves replacving the troublesome dual points system for a new rotor and pickup. (Check around for prices as you may be able to get it cheaper than RPi)

Your original dizzy looks like a Lucas DLM8 - It should have the model stamped into the dizzy body just below the cap. the weak point in that system is the electronic box (amp) which tended to suffer from vibration, heat etc.

That amp unit can be replaced quite cheaply - have a look here http://www.v8forum.co.uk/forum/viewtopic.php?t=78
and elsewhere on that forum for more info.


PS one other thought - Mallory distributors do like to run with the Mallory supplied coil. Not sure if the one in your top picture is actually a Mallory one

[Edited on 30/6/08 by robinj66]


Just about to type that word for Word but will add

Mallory had an issue with burning the points out but when working are good

I ran the DLM8 conversion shown on the link for 2 years ( wtf did they think that hiding a condensor in the box was a good idea !!!! ) and never suffered any spark problems.

I have had my v8 running with plug leads on wrong ( a couple of times but now they are labled !!) and using the proper cable seperators to seperate them from the rocker covers & each other.

Always worth a check if the engine will run is to run it with the bonnet off in the dark to see if you can see any of the leads arcking to earth.

regards

Agriv8

[Edited on 30/6/08 by Agriv8]


Alez - 30/6/08 at 04:43 PM

Thank you so very much. The majority of stuff is far beyond my skills but it's good reading and much can be tried. I would discard things like wrong parts, wrong wiring and so on, simply because the car was running great not long ago.

I have a replacement capacitor around and the previous owner mentioned the engine would get pretty mad on a faulty one, I'll replace it just to see what happens. Then if it's not that I'll see what I can do from your posts.

Thanks a lot!