7 replies to this topic

[bluemoon4444]

Help!

Installed new engine from Minisport 1293, stage 2 head. 1979, HIF44 carb, stage 1 exhaust.

Replaced all ancillaries as they were taken off old engine.

Established TDC, fitted distributor, connected all wires etc.

Engine cranks over fine but no spark from coil which is brand new and correct spec. Brand new battery also. HT leads also in good order.

I'm getting 12v+ at the + connection on coil, used test light with good earth and light is on when ignition turned on.

Placing the test lamp on both the + and the - terminals of the coil and the light briefly turns on but then goes out when ignition turned on, suggests a bad earth? But where?

It suggests there may be a short circuit somewhere but I have no idea where to check. I'm no electrics expert but have tried so many tests as per several forum posts and simply can't get to the problem.

Please help as I'm at the end of my tether!

[sledgehammer]

with known good 12v at +ve on coil

 

all wires off the -ve coil connection - earth the -ve with a wire , break the connection - you should have spark - if not coil is suspect

 

is the dizzi points or electronic ? - if electronic - module could be faulty

 

things to check -

 

tacho wire removed - eliminate another possible fault - also remove any radio suppressor on coil

 

if points - clean them up / replace - change condenser - look at insulation washer & make sure nothing is shorting to base plate

 

check fine earth wire in the dizzi (points plate to outer body)

 

run a new wire on it's own to the coil -ve & points (to eliminate wiring fault)

 

report back with outcome

 

best of luck

Edited by sledgehammer, 11 August 2016 - 10:03 PM.

[bluemoon4444]

Hi thanks for the steer. The dizzy is brand new and electronic. I understand earthing the -ve terminal on the coil, but just to be clear, if I do this, can I check the spark by holding the HT lead close to the block and checking for spark?

[sledgehammer]

you can  but better to connect a plug lead & plug rested on the head

 

less chance of a shock that way

[bluemoon4444]

Ok I'll try that tomorrow night, thanks. Will a plug lead fit on the coil?

[KernowCooper]

it will or use a plug lead, if the coil then produces a spark then the coil is not being switched by the electronic module, are you sure thats wired up ok ? tests for the module if the wiring is ok is in the FAQs Electrical Section. Shout back if you need any more help

Edited by KernowCooper, 11 August 2016 - 11:01 PM.

[Magna-Flash]

How to test your coil:

 

Remove all wires from coil.
Measure the primary resistance (ohm-meter at + and - connectors)... Depending on what coil you have you should get something around 1 to 4 Ohms.

Measure the secondary resistance (ohm-meter at + OR - and at the HT-connector). There should be a couple of thousand Ohms, usually 5000-10000 Ohms... again, depending of type/brand.

 

I´ve had a new Lucas Sports Coil (the shiny golden one) that had infinite resistance on the secondary winding - broken from factory... Minispares has stopped selling them because of high error rates.

Edited by Magna-Flash, 12 August 2016 - 02:28 PM.

[bluemoon4444]

Thanks for replies everyone. You won't believe this but the distributor drive spindle hasn't been fitted to the new engine which explains everything. A simple reason as to why the rotor arm on the dizzy moved freely and why ultimately I couldn't get a spark!

Not for a minute did I think I would have to check that on a brand new engine but a friend helped me tonight and that was what we discovered. Anyway have emailed Minisport and am awaiting there response!

Thanks again, much appreciated.