[Healeys] Austin Healey 100 Misfire Diagnosis.

Michael Salter michaelsalter at gmail.com
Thu Sep 29 07:38:15 MDT 2022


Thanks to all who have obviously given this misfire issue considerable
thought. I will be sure to check all suggestions.
I  should like to point out however that it is the immediate vanishing of
the misfire after filling the fuel tank that has me confused.
This has happened three times simce the problem appeared.
I just don't understand how an ignition problem could change as a result of
filling the tank.
Furthermore I'm convinced that this is not a fuel starvation problem
because the amount of engine power being used has no effect.
Totally baffled.
Thanks again to all ... I'll  report back.

On Thu., Sep. 29, 2022, 9:14 a.m. Alan Seigrist via Healeys, <
healeys at autox.team.net> wrote:

> Hi John -
>
> Yes, that was the point I was trying to make, sorry if it fell through bad
> interpretation!  As Ed McMahon used to say, "You Are Correct Sir!"
>
> Cheers,
>
> Alan
>
> On Thu, Sep 29, 2022 at 7:53 PM john harper <ah100tech at gmail.com> wrote:
>
>> Alan
>>
>> Coils can fail with heat and then recover when cooled. I had one that had
>> these symptoms and when looking closely I saw that the insulating oil had
>> run out through a very small crack in the bottom of the case.
>>
>> On Thu, 29 Sept 2022 at 10:34, Alan Seigrist <healey.nut at gmail.com>
>> wrote:
>>
>>> Michael -
>>>
>>> Just as a follow up to my email since the symptoms seem to manifest
>>> themself  ...
>>>
>>>    - whether the car is warmed up or not - this typically will exclude
>>>    anything related to fuel or the coil
>>>    - whether the car is under load or not - this typically will exclude
>>>    anything related to fuel
>>>    - whether the choke is pulled or not - this typically will exclude
>>>    anything related to fuel
>>>    - somewhat intermittent but systematically under all conditions -
>>>    suggests to me wiring / ground issues
>>>
>>> Given this I'd check (as a priority):
>>>
>>>    - Battery Master (when these fail they will ground the coil)
>>>    - primary ignition wire (white) from the switch to coil (cycle the
>>>    connections)
>>>    - motor ground straps (cycle the connections)
>>>    - loose wires in the dizzy
>>>    - loose ignition wires into the dizzy or spark plug
>>>
>>> Other things to possibly do (as secondary):
>>>
>>>    - replace rotor
>>>    - replace dizzy cap
>>>
>>> I don't think it would be contacts or condensor simply because this
>>> would either be very regular all the time, or maybe sensitive to temp.
>>>
>>> Best,
>>>
>>> Alan
>>>
>>>
>>> On Thu, Sep 29, 2022 at 4:46 PM Bob Spidell <bspidell at comcast.net>
>>> wrote:
>>>
>>>> re: "... I don’t recall if that wire is separate from the distributor
>>>> wire ..."
>>>>
>>>> It is (or should be). If the battery switch is in the 'OFF' position it
>>>> grounds the coil primary so no spark.
>>>>
>>>>
>>>> On 9/28/2022 8:34 PM, Alan Seigrist wrote:
>>>>
>>>> Hi Michael -
>>>>
>>>> Have you tried cycling the connections on the white wire from the
>>>> ignition switch to the coil, and also from the coil to the distributor.
>>>>
>>>> You might also want to try disconnecting the black and white wire at
>>>> the coil from the battery master switch - if it’s failing you’ll get weird
>>>> symptoms like this.  If that wire is disconnected the car should run no
>>>> problem.  I don’t recall if that wire is separate from the distributor
>>>> wire, if it isn’t you’ll have to disconnect it from underneath the master
>>>> switch itself.
>>>>
>>>> Best,
>>>>
>>>> Alan
>>>>
>>>>
>>>> _______________________________________________
>>> Support Team.Net http://www.team.net/donate.html
>>> Suggested annual donation  $12.75
>>>
>>> Archive: http://www.team.net/pipermail/healeys
>>> http://autox.team.net/archive/healeys
>>>
>>> Healeys at autox.team.net
>>> http://autox.team.net/mailman/listinfo/healeys
>>>
>>> Unsubscribe/Manage:
>>> http://autox.team.net/mailman/options/healeys/ah100tech@gmail.com
>>>
>>> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation  $12.75
>
> Archive: http://www.team.net/pipermail/healeys
> http://autox.team.net/archive/healeys
>
> Healeys at autox.team.net
> http://autox.team.net/mailman/listinfo/healeys
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20220929/bcf3b795/attachment.htm>


More information about the Healeys mailing list