Now issues..

two tests:

First, just take the extender by itself, disconnected from everything, holding it in your hand by itself, measure resistance while flexing the extender checking for a short. This is how i determined I had a bad extender. It tested fine but when i flexed it, it failed.

Second, when you pull the cap off the distributor, pull all wires from the spark plugs so you have the cap, wires, and extender (but not the sparkplug) lying on your kitchen table (if you are allowed to). Then test resistance from the copper terminals in the distributor cap all the way to the end of the extender, wiggling all the bits checking for a short. Also, check the coil wire in the same way.

others may have different/better ideas. It must have something to do with the wires/cap connection/extender....

or maybe just put the old plugs back in and see what happens...

Geno

 

sounds like you found the culprit, good job.

i bet that #4 wire was just hanging on by a thread, and when you replaced the plugs that was enough jostling to disconnect it entirely.

Its a very easy job to reset that wire, if the the caps look ok (and they do in the pics).

Even if you bought new caps and new wires, its still and easy job, plenty of threads to walk you through the process.

basically, that set screw pierces the inner element of the spark plug wire. You can double your chances of hitting the wire by stipping back a bit of the outer sheath and doubling the innner element over itself before pushing the wire back in the hole.

 

take the offending wire, strip the outer sheath off, exposing about 3/8" of inner wire, double it back on itself, jam it back in the hole, set the screw and fire it up.
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also not sure, but your carbon button looks flat. it should stick out, and when you push it in it should spring back (at least it does on teh 308).
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I noticed that as well in the photo's. The new rotors do not fit in the shaft properly and with them not bottomed, they bury the carbon brushes into the cap. The big question is if we can free them without destroying them.

That stated..... now lets talk abot the photo of the cap you posted. WTH happened to the terminals on this one? Rotor acting like a lathe cutter bit?

All of these new parts are absolute rubbish, not worth the labor to put them on! I dont know why I started saving old caps and rotors decades ago but I am damn sure glad I did. I would replace a bad cap with an old used one LONG before I would put "new" on the car. Folks wanted cheap.... ask for it and you got it BUT, you forgot to also state you wanted the cheap part to be a reasonable quality.... someone is making good money here, that I assure you! By the time you factor in the costs of chasing rogue gremlins created by the cheap parts it near triples the costs and makes the old Marelli parts look like a bargin.

 

http://www.ebay.com/itm/New-Complete-Set-Spark-Plug-Wire-Clips-Ferrari-308-328-/140757207902?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item20c5c88b5e

For a set of wire clips - they are hideously expensive if you buy them individually.

Did you check the wires themselves for continuity?

 

Reproduction distributor caps are available from Dennis Mccann for $144. They are exact duplicates and work perfectly. You can also get the carbons from him for around $10.

When I re-did my ignition wires the carbons were frozen in the cap and I was able to drill them out without damaging the caps. Just don't drill too deep or the screw at the bottom of the hole will be damaged. I believe I used a 1/4" drill which also pulled the spring out.

One cap has been corroded due to some condensation and I could not get any of the screws which hold the wires out, thus I replaced that cap with one from Dennis. As I said, it was a perfect fit.

Also, there is not need to strip back the wires before inserting them into the cap. The brass screws penetrate the wire when tightened and make the contact.

The clips from T. Rutlands are the ones to get.

Wire resistance should be a few 100 ohms, less than 1k Ohm. Exact value is not critical.

 

I also used new caps (from Ferrari) last year & they have been fine (and have no branding on them). Wire resistance will go between about 650 for the shortest ones & 1100 ohms for the long ones (on a brand new set). I've measured that 2 or 3 times over a few years & it doesn't really change. The thing to check with the wires is just end to end continuity. They will usually still work if there is a break in them (because the spark jumps the gap) but over time they start to misbehave & then eventually fail.

 

I rebuild my wires with Belden 7mm spiral wound ($35 from NAPA) which is actually much better quality than the original Cavis wire from '85. My car was missing at low rpm and I traced it to the wires. They all were infinite ohms (meaning breaks in the wire some where along the length). A couple of the wires were really bad with breaks every couple of inches.

One thing I think a lot of people don't understand is that ignition wires are not like ordinary wires as they are not intended to conduct any significant current. They function by providing a path for an electromagnetic pulse (EMP) to follow to the plug where the spark is created. Breaks along the length weaken the strength of the pulse, thus resulting in weaker spark. More breaks, weaker spark, until you finally develop a miss.

A mistake often made is that people replace the spiral wound wire with a solid conductor thinking it will make the car run better. This is not a good idea since one of the reasons to use spiral wound is to suppress radio noise (high frequency hash). This electromagnetic noise can have an impact on the ECUs performance and even result in their failure. I have wondered if the failures of some Digiplex modules may have been related to substituting solid conductor ignition wires for the correct spiral wound.

 

Thanks for the explanation - "EMP "-- sounds positively Star wars!

I have read about people having isues with trying alternative wires. The OEM ones are expensive (though maybe not quite so bad as before now that they include the coil leads in the wire sets) but they do last.

The ones I replaced last year were, I think, the originals on the car at 20+ yrs old - they certainly hadn't been changed since I bought the thing in 1999 & until I found 3 or 4 of them had suddenly developed breaks within a 6 month period they had been fine & the resistance in them hadn't changed either. So in that context maybe the OEM wires are not quite so dear as they look & for what can be saved by going elsewhere (unless you build your own) , I decided it wasn't worth the hassle.

 

All Ferrari Parts in Ohio, http://www.allferrariparts.com/


Search part #115518

 

I discovered those grooves when I was chasing down a short. I wound up rebuilding the distributors (bad bearings causing the rotor to spin off-axis?) and installing pertronix. I bought new caps, and just for an experiment I put the old worn cap with the grooves back on, and it fired just fine....

 

Just to check - are your rotor arms pointing in basically the same direction as each other? (because they should be)

 

The terminals on your caps look fine. Dave seemed to be commenting of the pic posted by Sledge4.2.

 

I dont doubt they worked, usually do.

Those bearings had to be missing more than 1/2 of the balls in each for the rotor to spin that far off axis.

Yes sorry for the confusion, John is spot on, I was commenting on Sledge's photo.

The rotors not fitting correctly on the shafts, causing the button to br driven deep into the cap.... that started happening about 8-10 years ago with new batches of rotors being supplied. At the same time we started to see the posts cut to shreds like in Sledge's photo, usually from the rotors either being disformed from forcing them on the shaft or from the rotor body itself being poorly formed and not running true. We started to see that long before the current batch of caps and these new points came available.

 

Jeff,

Good to read you have found the most likely culprit.