12 replies to this topic

[CityKie]

###########           Warning get a cup of tea and a violin at the ready            #####################

 

so my MG metro turbo engined Mini is coming along, slowly but surely...I keep getting bogged down with issues but they are being resolved and on to the next.

 

I have my engine turning over when trying to start from key, I have an electric fuel pump triggered through a relay triggered from the ignition live on the fuse box.

 

What i do not have is spark !!! 

 

I have a Avonbar turbo dizzy converted to electric by Avonbar before they sold up to MiniMine.

 

This was send to a specialist for a check up and came back with a full bill of heath and the suggestion to use it with a DLB198 coil. 

 

I'm taking power from the Ignition on the fuse box (top left) to the coil and the dizzy power from the coil, the same connection that triggers the fuel pump relay.

 

I have a set of spark testing bulbs all showing nothing.

 

I have checked the dizzy with the cap removed, the arm is turning as expected 

 

What i have tried.

 

power direct to the coil from the starter (live feed)

 

earth provided from the under bonnet earth connection

 

running a jump lead from the battery earth to a manifold bolt.

 

New coil 0.8ohm

 

New coil 3.0 ohm

 

The original MG turbo Dizzy with new and tested electronic module with the DBL198 and the original MG Turbo coil 0.8ohm

 

2 sets of HT leads

 

Tested the dizzys connecting the earth to a test bulb then to live, I get a good strong pulse when turning over on both dizzys

 

tested the primary and secondary coils with an Ohm multi-meter, all showing what is expected, 0.8 on the two electronic coil and 3.0 on the normal (non ballast coil)

 

 

I have replaced :-

 

The battery

Fuse box

Live wire from battery to the starter

Engine earth strap

MG dizzy electronic module and tested the power supply successfully

Avonbar dizzy is new and has been recently tested by an ignition specialist. 

 

 

Out of shear desperation i have just ordered a further set of high end HT leads a new Dizzy cap for the Avonbar dizzy along with a new battery earth cable ( mine has a few wires broken) 

 

can anyone anywhere suggest anything I have missed or not considered ? I am going slowly crazy and running out of coil credits !! :)

 

thank you 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[sonscar]

Has the dissy two wires coming from it?One is live to power the switch and the other goes to the coil negative.The switch causes the coil to earth to charge it up then turns off the earth to cause it to fire.beware as I am not familiar with your setup.
Points do the same thing,turning the coil earth on and off.Steve..

[CityKie]

yep both dizzys I've tried take 12v+ and 12v- from the coil. I've tried powering the coil from a constant live and from the ignition 12v + on the fuse box, top left.

[sonscar]

Stick a lead and plug directly into the coil and try it,Steve..

[CityKie]

hey thanks for that I've just tested all three coils.

 

2x 0.8ohm displays a really weak light on the spark tester bulb when connected to positive ignition and continual positive from the starter. The 3.0ohm was slightly more visible

 

edited to add, I was seeing a voltage of 12.88v on the power supply to the coil. battery just charged

Edited by CityKie, 11 May 2023 - 02:30 PM.

[CityKie]

i've fitted the new battery earth strap, tried a new Viper Coil and top notch HT leads and ............................ nothing !!

 

I'm so confused, i tested the voltage across the coil wired up from the fuse box it was only 10.8v, i then took the live feed from the starter and i was getting 11.8v..

 

I'm gonna try to put an additional battery in parallel see if that helps.

 

Any more ideas from anyone  ???? I'm stumped !

[gazza82]

If your battery is only 11.8v it's a duff ..

[lordcakes]

Check all of your power connections and cables, including your fuse box for bad or corroded connections. If your battery is giving a decent voltage but you have low voltage at the starter or could then this may be the issue.

[CityKie]

thank you Lord (it's defo Sunday :)). I've even got jump leads direct to another battery, with a jump pack to be sure no drop in voltage. I've then taken the power from the battery, fuse box is new, as is the live feed etc. Its been a subframe off rebuild. I was able to measure 12.8v across the coil tonight. I have even fitted a new dizzy cap.... it all points to the dizzy but I'm able to get a pulse with a test bulb on both electronic ones I have.

 

I've got someone else to give it an new set of eyes in a week or so... I'm hoping for a "can't see the wood for the trees" scenario ! but I can't think WFT it could be I had the engine running on the floor of my garage on the point based Avonbar turbo dizzy before i fitted it ! 

Edited by CityKie, 14 May 2023 - 05:47 PM.

[sonscar]

Mark where the wires have come from and remove them all from the coil.Fit a plug into the coil lead and ground it to the engine.Connect 12v to the coil positive.Connect a wire to the coil negative.Briefly touch the wire from the negative to the engine and remove it.Connecting it charges up the coil and removing it causes it to spark.This is what the points or ignitor do,they connect and disconnect the coil to the engine earth.This will test the coil.
If you have points then fit them correctly using a good guide.connect the wire you had been stabbing onto the engine to the points wire.Spin the engine and check the coil for spark.This tests the points.
If you have spark at this point then connect the coil and plug leads,spin the engine and check for spark.This tests the cap and rotor.Do all these tests in this order.Steve..

[68+86auto]

What year is the mini? it sounds like maybe you are powering the coil and electronic module with the resistive wire for a ballasted ignition which is not 12v when there is current through it.

[viz139]

The one thing you haven't mentioned replacing is the rotor arm . Have you put a spark plug directly on the lead from the coil to see if it will spark before entering the dizzy cap. I had a situation years ago of rotors failing after a few hundred miles. As an electrician i tested the metal for continuity which was fine and the plastic for insulation for resistance which was fine but they would not work. When I fixed the source of the problem I talked to my local Rover dealer about sending the rotors for testing but they said the part was so cheep it wasn't worth it so never found out why they wouldn't work at that point.

[bpirie1000]

What colour of wires do you have on the coil and do you have the ignigtion module on the side of the dizzy that looks like this?

https://www.ebay.co....QhoCpdcQAvD_BwE

As in a 65d dizzy?

Sounds like ballast resistor issues..