Spark Plug Connnector

[Silver73tii]

Good day all,

 

When I pull the connector off the spark plug, the rubber bushing at the plug end stays stuck on the plug and not on the wand.  I then have to pull it off the plug with forceps.  I've tried a small amount of grease on the inner surface where it sits on the plug but that didn't solve the problem.  What do you all think?

 

Also, for some time I have a slight intermittent high speed miss.  Just a missed beat 2-3 times a mile while cruising along at 70mph.  The reason I'm messing with the plug wires is the miss feels like an ignition issue to me and I want to check that all the wires are sell connected.  I did find one where the wire itself was not fully screwed in to the wire end of the plug wand.  that didn't fix it.   I've replaced plugs, condenser, points, cap, coil and rotor.  Still have the miss.  Could it be spark plug wires?    Pelican has plug wire sets for $46 and $242.  Does anyone buy the $242?

 

I look forward to your thoughts.

[Son of Marty]

A little contact cement between the boot and Bakelite terminal will fix you right up. I just use 3m weather-strip adhesive not the hi temp stuff worked like a charm.

Edited November 20, 2023 by Son of Marty

[John76]

I've never had a rubber insert in the ceramic spark plug connector.

There should be a small clip that holds the connector to the threaded end of the plug. 

These ceramic (Bakelite) connectors are meant for use without the screw-on (or permanent) plug tips.

 

[Mike Self]

An alternative to contact cement on the rubber bushing's outer surface is a little silicone grease on the inside, so it'll slide right off the plug.

 

And...the plug terminals that came on the cars from the factory didn't have those rubber inserts...in fact they don't appear to have made an appearance in wire sets until sometime in the 21st century.  Without 'em the terminals kinda flop around even though they're firmly attached to the spark plug--but I've never had one come off...

 

So don't be too concerned.  

['76mintgrün'02]

Yes, it could be the plug wires.  Kingsborne sells nice sets.  Mine still seem to be doing well after ten years of use.  (They don't have the rubber booties at the plug end). 

 

[Son of Marty]

I sourced the boots from Volvo in about 1974 they were standard on their cars at the time and used the same Bakelite connectors as BMW and I'm sure others of that era.

[stephers]

The rubber boots were never there on the original set ups, one of the after market sellers started putting these boots on their kits and pretty soon, everyone was doing it and seems now, think that that this is normal       At services, we would unscrew the connectors, cut a little bit off the end of the ign wire and rethread them back on ( as long as they were not cracked or broken )      Don't be in a such a rush to replace everything, get an Ohm meter and check them all, you can check the wires themselves separate from the connectors which can be checked as well individually       Test first, verify and then replace if necessary 

 

Thanks, Rick

[TobyB]

Quote

At services, we would unscrew the connectors, cut a little bit off the end of the ign wire and rethread them back on 

 

This.   The bare end of the wire impales onto a spike on the inside of the plug end, and with time and vibration,

that connection loosens up.  Often, just a twist of the plug end back onto the wire will do the trick, and restore a

good connection.  But if it doesn't, use Rick's technique, and cut maybe 3/8- 1/2" off the wire and push and 'screw'

it back into the plug end.

If you are unlucky and have carbon conductors, they tend to break off right above the spike end in the plug 

connector if the wires are not well- supported.

 

I've never had any luck with those dumb little rubber booties.

 

t

 

Edited November 20, 2023 by TobyB

[dlefebvre02]

6 hours ago, Silver73tii said:

Also, for some time I have a slight intermittent high speed miss.  Just a missed beat 2-3 times a mile while cruising along at 70mph.

 

What plugs are you running? I have a '76 and was using the BP7ES as per spec, but the plug turned out to be too hot (I had removed the smog parts). This resulted in occasional misses on acceleration at at cruising. Swapping to a BP6ES, or resistor equivalent, completely fixed the problem.

[John76]

54 minutes ago, dlefebvre02 said:

I have a '76 and was using the BP7ES as per spec, but the plug turned out to be too hot

The BP7 plug is too cold . 

I used BP6 's but switched to the next hotter (BP5) to keep the plugs cleaner on a "tired" engine.

I'm refreshing the lower end with new rings etc. (head was rebuilt 5k miles ago) and will most likely go back to the BP6.

Can't wait to get 'er all back together and tuned with a A/F meter.

Stay tuned,

John

 

[Silver73tii]

Hi Guys,

 

Sorry for the lack of response on my part.  I am running Bosch WR7DC plugs.  Running pretty good now.  i am confused by the above discussion on heat range.  Bosch numbers higher is hotter.  

 

David

[John76]

Yes, the Bosch plugs get hotter with higher numbers ... opposite of NGK and Denso,

 

Here's what I have from my "trusty" notebook.

 

47 minutes ago, Silver73tii said:

Bosch numbers higher is hotter. 

 

[Silver73tii]

Thanks John and what do you think of running the Bosch WR7 in the tii?  They have a nice tan color which I think indicates a good match. 

 

Also, do you gap your plugs?  The owner's manual says the plug gap should be .024"   The plugs come with a gap of .030" or more.  Do you tap them down?  Years ago I spent time doing that but have ignored it recently.  Never seemed to make much difference.  But the Bosch web site recommends setting the gap.  Your opinion please?

 

David  

[John76]

1 hour ago, Silver73tii said:

The owner's manual says the plug gap should be .024"

The factory recommends a gap of .024 - .028" for a stock engine...i.e. stock coil, timing, CR, A/F, fuel type, cam, thermostat, etc.

I use the .028" gap on my stock (low compression) '76 with the PerTronix Ignitor II ignition and 0.6-ohm coil.  

Before the switch from points to PerTronics, I found the .024" gap worked better (easier cold starts).

 

 

 

[Son of Marty]

Always check the gap on your plugs just because it said pre gapped doesn't mean that they were gap to your spec's or not dropped or banged around before you bought them, just my opinion.