8 replies to this topic

[cooper80]

I;m having difficulty in getting my fiance's 91 carb cooper to start. Turns over fine but no spark at plugs, have removed one plug and tried to spark against the engine but nothing. Starter motor, dizzy cap, rotor arm, coil, ht leads and plugs all replaced and nothing.
The coil resistance is around 1.5 ohms so I'm guessing this is a ballasted ignition? There are two wires to coil + and 2 to coil -being white lead from loom and white from dizzy to + side and blk/wht form lom and blk/wht frmo dizzy to - side is this correct? I've done a search but only found details for different coloured wires (pink or yellow etc)?....

The starter motor has the batt + feed, and 2x 2 br wires some terminating at the alternator and one to the engine block by the thermostat housing. There is also one br/red wire connected to the starter motor, and one emtpy spade connection.

Sorry for all the info guys but its really starting to do my nut in! I have not yet checked the coil voltage, I know there is nothing there with the ignition on, but I assume this only becomes live when attempting to start?...

Pls help!

Thanks guys

[THE ANORAK]

the ignition module (little black box on the side of the distributor body) may be at fault.

there are instructions for testing this in the Haynes manual i think.

[Silicon Skum]

Yeah chances are it's the Hall effect sensor (ignition module / black box on dizzy) that has failed. They are fairly sensitive to static electricity or voltage spikes on the charging cicuit. They can also just fail for no reason.

Swap it out and it should fire straight up.

SS

[cooper80]

Thanks guys for all your help, I'll try and pick a new one up today and swap it about, its about the only thing that hasnt been renewed!!

Fingers crossed!!

I've noticed that the battery neg lead is warm to the touch after attempting to start the car, which I assumed would mean a bad earth somewhere. Ive renewed the engine earth strap and the batt neg connection is clean and well connected.

I may well be back later for more advice!

:)

[THE ANORAK]

hope the ignition gets sorted, as for the battery lead, this is quite a common problem if you have just fitted a larger bore exhaust, the live cable can sit very close and get "melted through" so check this first.

also a quick pointer towards the link below my signature, being a fellow cooper carb owner you may enjoy the site.

[cooper80]

I;m back! Still no joy, I removed the ignition module form the side of the dizzy and found corroded connections, so much so that one of them broke as I removed it. Right, I thouhgt, so a replacement module has been brought and firrted, and......... still nothing!!
I;ve checked the feed to the coil + which is getting 9.5V when turning over, although I didnt measure the battery voltage, I imagine this will have dropped somewhat due to many starting attempts so doubt it is dropping 3V from Batt to coil. There is no spark from the coil main lead, or to any of the plugs. My only thought now is that I have connected the HT leads in the wrong order, although I repleaced them one at a time to avoid any confusion!
I've checked the position of the rotor arm, but is at sort of 9 o clock position when looking through the grille at it.
Really losing my patience with the old girl now, any thoughts greatly appreciated. Have not checked exhaust mounting / positive cable yet.

[THE ANORAK]

mmm, well i had much the same symptoms with mine last year and replacing the module sorted it out, so sorry but i'm stumped now.

just one thing to check, did you connect the wires from the module to the coil correctly ???

i'm not trying to imply your thick or anything, but i made this mistake when fitting mine

[taffy1967]

This is the correct HT Leads sequence: -

I've checked the position of the rotor arm, but is at sort of 9 o clock position when looking through the grille at it.

You can usually only get it on in one position anyway I believe?

And try not to get too annoyed, because it's probably something simple and have you replaced the coil too?

Edited by taffy1967, 04 May 2007 - 05:33 PM.

[cooper80]

Thanks for the diagram above, will check this when I get in tonight. I had a flash of inspiration lol and put the old coil back on. No change however and still no spark

I cant remember the connections from the module to the coil, so will check them too tonight. I think its 2 x blk/white to the + sode and 2 x wht to the - side. Does this sound correct?

Might try using a jumpoer cable as an earth and see if that helps, as am running out of ideas. I noticed that one of the leads under the steering column cowl has at some point been cut and has been crudely twisted together, however, I have not delved further into this to see if this is relative to the ignition or another circuit.

AA man started it a while ago by using a battery booster. May resort to jumpers and see if it goes then. Am I looking at an earth problem if the extra voltage passing throguh finally gets her to start?

Sorry for all the questions guys! You're doing a great job of helping me so far, so many thanks to all who've contributed! :)