Author Topic: Spark plugs or leads???  (Read 425 times)

Offline Hercplt

Spark plugs or leads???
« on: August 17, 2020, 03:45:49 PM »
Ok.. I have good spark at the main HT lead to the dist.  Spark at each of the leads (holding a screw driver and arcing to the block).  Intermittently,and mostly not, I'm not getting a spark in each plug.

When I do get a spark at the plug (holding the lead) I'm feeling quite a shock.

Electronic dist module.  New dist cap, new plugs (but I've had them in and out a bit)

Any ideas?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Online 94touring

Re: Spark plugs or leads???
« Reply #1 on: August 17, 2020, 04:06:52 PM »
Have you swapped out the coil yet?  Do that and see if it's consistent.

Offline MPlayle

Re: Spark plugs or leads???
« Reply #2 on: August 17, 2020, 05:12:13 PM »
It sounds like you are getting good spark from the coil to the cap, but inconsistent out of the distributor cap.

Check the rotor under the new distributor cap and be sure it is making good contact at its center.


Offline Hercplt

Re: Spark plugs or leads???
« Reply #3 on: August 17, 2020, 05:41:25 PM »
The coil tests great, and the spark out of it is quite strong... I don't think thats the issue.  I find it strange that the spark comes through the lead to the plug... but not out of the plug itself.

Everything is basically new...
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Offline John Gervais

Re: Spark plugs or leads???
« Reply #4 on: August 17, 2020, 06:58:01 PM »
A silly question, but are you grounding the spark plug when you test it?

I don't like to hold things with 'lectricity flowing through them, so I take a bit o'copper wire and tie the threaded portion of the spark plug to a head stud.
- Pave the Bay -

Offline Willie_B

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Re: Spark plugs or leads???
« Reply #5 on: August 17, 2020, 07:29:24 PM »
What plugs are you using. Do they have a "R" in the number? Those would be resistor plugs, not needed.

Offline Hercplt

Re: Spark plugs or leads???
« Reply #6 on: August 17, 2020, 07:51:33 PM »
Using RN9YCC Champion plugs...  Whats the deal with the resistor type??  I think this is the type the Haynes manual suggests.  Would welcome other suggestions.  Other Champion or Bosch??

I tightened up the clip in the leads where they attach to the plugs... fired right up.  They were loose.

Edit:  So apparently Haynes says N9YC or N9YCC... so.. question; would the wrong plugs be a source of a regular misfire particularly under load??  I have some NGK BP6ES plugs kicking around... gonna try them...

« Last Edit: August 17, 2020, 08:14:29 PM by Hercplt »
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Offline Jimini II

Re: Spark plugs or leads???
« Reply #7 on: August 17, 2020, 08:24:35 PM »
I don't use Champion spark plugs anymore and haven't for a long time, NGK BP6ES spark plugs seem to work much better in a Mini.

Online MiniDave

Re: Spark plugs or leads???
« Reply #8 on: August 17, 2020, 08:45:25 PM »
I agree, I used to use the Champions years ago, but now run the NGKs exclusively.....
1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Offline Hercplt

Re: Spark plugs or leads???
« Reply #9 on: August 17, 2020, 09:09:00 PM »
Ok. .. but would the resistor type cause running issues?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Online MiniDave

Re: Spark plugs or leads???
« Reply #10 on: August 17, 2020, 09:48:51 PM »
Shouldn't.....no. But it's easy enough to find out, just drop in a set of non-resister plugs.
1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Offline MPlayle

Re: Spark plugs or leads???
« Reply #11 on: August 17, 2020, 09:52:29 PM »
Resistor plugs by themselves should not be an issue.

I seem to recall reading somewhere recently that you do not want to combine resistor plugs with resistor leads though.  Apparently the combined resistance is supposed to weaken the spark?

Making sure you have solid connections everywhere is also critical.




Offline Hercplt

Re: Spark plugs or leads???
« Reply #12 on: August 26, 2020, 04:35:15 PM »
For the record...  Champion RN9YC (resistor type)... car runs like s**t.  NGK BP6ES (non resistor)... car runs 95% better!!

1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Online MiniDave

Re: Spark plugs or leads???
« Reply #13 on: August 26, 2020, 06:37:42 PM »
Yeah, I gave up on Champions a while ago - I only run NGK's now....resistor or otherwise.

glad you got it sorted!   77.gif
1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Online 94touring

Re: Spark plugs or leads???
« Reply #14 on: August 26, 2020, 07:36:47 PM »
Ngk's and I run brisk gapless plugs on my heavily ignition built mini.

Offline John Gervais

Re: Spark plugs or leads???
« Reply #15 on: August 27, 2020, 05:38:30 PM »
I use NGK B6ES -
- Pave the Bay -

Offline Hercplt

Re: Spark plugs or leads???
« Reply #16 on: October 08, 2020, 08:05:39 PM »
Sorry for bringing up a older thread... but riddle me this...

I have a Intermotor brand sport coil... measuring 2.8 ohms across the + and - posts.  And 8800 ohms across + post and HT lead slot.

I was expecting 3+ ohms and 10000+ respectively.

Could this be a problem for me... in context of my compression and misfire issues????

Rich
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Offline LarryLebel

Re: Spark plugs or leads???
« Reply #17 on: October 08, 2020, 11:12:28 PM »
I'm using the same coil on my 1275 Traveller without the issues you mention. If the spark is blue the coil is fine. What plugs are you using, not Champions I hope. What's the issue with "compression"?
« Last Edit: October 08, 2020, 11:17:09 PM by LarryLebel »

Online 94touring

Re: Spark plugs or leads???
« Reply #18 on: October 09, 2020, 08:02:59 AM »
Sorry for bringing up a older thread... but riddle me this...

I have a Intermotor brand sport coil... measuring 2.8 ohms across the + and - posts.  And 8800 ohms across + post and HT lead slot.

I was expecting 3+ ohms and 10000+ respectively.

Could this be a problem for me... in context of my compression and misfire issues????

Rich

Ohms won't fix your sickly motor and low compression.  Unless the name of the engine builder is Mr. Ohms.

Offline Hercplt

Re: Spark plugs or leads???
« Reply #19 on: October 09, 2020, 10:55:46 AM »
Perhaps I should rephrase my question.  If the engine was otherwise good as far as compression is concerned.   Would a coil be considered suspect with those numbers?
1980 Mini 1000 (Canadian Spec).
998cc +60.  12G295 Head (ported, skimmed etc), VP7 Cam, Twin HS2.... sweet sweet 7.5" Cooper brakes!

Online 94touring

Re: Spark plugs or leads???
« Reply #20 on: October 09, 2020, 10:59:52 AM »
Probably not.