Hi All: Question here: At what point should ignition wires be replaced, and is there a means to test them? I've searched a good number of threads, but perhaps I haven't found the answers to my exact questions yet. First off: My 87 Mondial last had it's ignition wires and coils replaced in January of 95, roughly 30K miles ago. They appear to be OEM. It's had routine services since then based on time rather than mileage, but no new wires or coils. Everything else on the ignition system is much more recent. 30K wouldn't be many miles on most cars in terms of replacing the wires, but should I assume that the more powerful ignition will have done in the wires by now? Also, is there a useful way to test them? I can easily test the resistance, but some of the online research I've done indicates that isn't useful, as the resistance is not the same at the energy a multimeter applies, as opposed to 40K volts. That is, wires that test with zero or low resistance may in fact be no good. Anyone know the answer to this? Also, are resistor wires needed or not? The car has NKG D8EVX plugs, which I don't think are resistor, but I haven't had any noise on the radio. Should plug OR wires OR both be resistor? Finally, is there a reasonably priced alternative to the top end wires out there? I noted in the cross reference thread the Accel 4040R, although that appears to be only for carbed cars. Not that I really want to skimp, but $400+ for the wire sets seems a bit extreme, what justifies that price? I wouldn't mid skipping the risers with long boots, I doubt much crud or water would get down into the holes. My previous two cars had a similar arrangement, one had risers and the other didn't, and other than worrying about originality, the risers don't seem to do much other than look neat. Or am I missing something? I don't tend to drive very hard, so the best spark isn't a requirement. At the moment though, start-up is pretty smelly--I think due to incomplete combustion. Not a raw fuel smell, just a strong exhaust smell. Thanks in advance for any help, I've already gotten so much from this great community.
typically i would say every 8-9 yrs when you do a complete engine out (when doing the belts) I would do new rotors and wires....as for caps; thats a different story, maybe clean them out as opposed to buying. Usually the rule of thumb i use. And for hoses i would go every second run which would make the hoses 18 yrs old. As for the wires, if you think they are old, change them, if by chance they start to arch, you will end up replacing the cap anyways when you may not have too. This thinking has served me well to date.
If you change the wires, you might as well change out the Plug Extenders (the long red 'cones' that go down the spark plug hole and physically connect to the spark plug). If you just buy a set of wires, the wires usually stop at the red 'cap' that connects to the top of the Plug Extenders. You typically can source both items at the same location/vendor, but are often sold seperately. Both are considered 'wear items' that are replaced simultaneously, since both are affected by engine heat and operational wear at the same rate. The cheapest place I've recently seen 308 Rotors from Magnetti Marelli are from our good British friends at SuperPerformance. They also source Caps if you feel you need those (I've only heard folks replace them if they're cracked), as well as the Gasket that seals the Distributer Cap against the engine - you'll need a fresh set if you're 'going in there' to replace the rotor. You'll also want to inspect the oil seals in there - again, SuperPerformance has all of these goodies in-stock and at reasonable prices. Stateside vendors seem to want to RAPE you for these parts, if they bother to stock them at all.....
Do A search, but most of us have changed to Taylor Wires. I bought a set of 8 New Spark Plug Extenders from a company for $66.00 including shipping. And a set of the universal Taylor wires ( in Red) were about $60.00. The universal set has spark plug ends in different angles. I selected the 135 degree ones. If you use upgrade to 8MM wires, you will have to shave the cable ends that go in the Distributor Cap. Charles
I have Magnecor wires on my GTSi. I think the set was $130 and I bought new extenders and distributor caps and rotors from Dennis McCann. You can call Magnecor or check their website for current pricing/info...but they make wiresets to order and are very speedy and their tech people have been excellent. My car had OE Cavis wires and they looked pretty old so I replaced them as matter of caution even though the car ran fine. Cheers; Aaron '82 GTSi
I just commisioned Taylor to make me 5000 feet (I bought the last of the remaining bare stock materials they had in the plant) of the 7MM silicone jacketed Spirocore wire that should be done in the next few weeks. I have had enough problems with availabilty and quality of the other brands to warrant the effort and expense. Shaving wires and reaming $400.00 + caps is a risk I am no longer willing to take and on the Vintage cars it stands out like a sore thumb. Dave
A resistance test is a good start. Any non-resistance wire that tests zero or VERY low resistance is good (but does not mean the insulation is good). Resistor plug wire will never have an abnormally low reading. It will read high or infinite (open) if there is a break in it. Don't forget to wiggle and bend the wires a bit when checking resistance to see if the reading jumps around (a break somewhere in the conductor). The next test I would do is to spray a fine mist of water (when it is dark) and with the engine idling, on the coils, coil wires, distributor caps all the way to where the plug wires go into the heads. If you don't see any little lightening bolts jumping around your wires and insulating caps, distributor cap(s) SHOULD be good. Resistance does not change with the amount of voltage applied (increasing the voltage applied to some conductors/materials would increase the current flow which would increase the temperature which could change the resistance of some conductors/materials to an extent but it does not really come into play with plug wires). Keep in mind that at idle the voltage produced by the coil(s) will be at its lowest. As rpm's increase the output voltage of the coil(s) will increase. Arcing that does not occur at idle might occur at 7000 rpm if some insulation is marginal. Still, if all these parts check good for resistance, they are clean (free of grease etc.) and pass the spray bottle test at idle then I would be pretty comfortable with that.
Have you been able to source the Cavis connections for the Taylor wire, giving the plug-wire set an OEM appearance? I'd like to maintain that stock appearance....
We simply thread new wire into the OE silicone tubing after it is cleaned up. The silicone tube and end boots last forever. On that note, I am a buyer for any old plug wire sets anyone has laying around. A little labor gets an end product that is far superior in quality. I am looking into having some of the silicone tube made as well but need a new length so seldom that it would have to be quite cheap to warrant investment in that. It took me years of dealing with what is currently available before I could justify buying 5000 ft. of this! I can find many more items I would rather invest in and keep in stock. Dave
Wow, I don't look for a few days, and all these responses. In the meantime, I have new plugs and extenders on the way. So far, Magnecor looks like the best bet, although it appears I would take the boots and silicone tubing of my old set, which makes me nervous--what if I screw up both sets somehow? Anyway, I haven't tested resistance yet, since I'm not sure of the ohms/foot. In some searching of the archives, I read that someone thought the factory wires should be about 350 ohms/foot. Can anyone confirm this? It appears that Magnecor is around 3,000 ohms/foot. I did go out recently and look at the wires while the car was running to see if there were sparks. None--and I've had those occur on a car before. I put a test lead onto a screwdriver, which I then grounded to the chassis, and ran it along just over the wires to see if I could get an arc--none. Perhaps the wires are fine. I'll be curious to see what the plugs look like when I put the new ones in. Yes, I know I should already have looked, but I've got two little kids, and the only tinkering time I have is at 1-am. I'll look at the plugs when I have time to replace them, too. The wires on the car look fine, clean and no abrasions. I guess the question is: do they degrade internally short of actually breaking? The car runs smoothly enough, but I nearly asphyxiated myself in the garage running it. Maybe it's the fuel injection.... Thanks for all the responses. Peter
The conductor should not degrade in any way other than as you mentioned, the possiblity of a break/gap developing.
If you have the red extenders there is no reason to EVER change them unless they show signs of arcing. The conductor is a solid piece of metal. It will not go bad. There is no resistor or resistance material in the red extenders. Realisitically speaking the only failure you could have (other than a crack maybe from heat cycles) is arcing and you would see traces of that on the extender (little black mark(s). I think a lot of people waste money changing these. Spark plug wires are something of a "wear item" but not the red extenders. Maybe people change them because of the "feel good factor." They're relatively inexpensive and some people get satisfaction from changing a part after so many years or miles but I think the money could be better spent elsewhere.
I redid mine and tidied the wiring up and made special holders and gromets this is how it turned out. Cheers MG Image Unavailable, Please Login
Sorry, Moretti in the Oz section says the same thing. He says I'm Sick! The hoops with the cylinder numbers are the originals. When I ditched the points and went for the new ignition system, i used the 8mm leads. So to fit the originals you get a hair dryer( don't tell my wife) heat them slightly and use a tube expander ( plumbers tool) to get them to the right size, when they cool they don't move.
I don't think you are. I am now convinced the only way I am going to get to that level of "clean" is the pull the motor. I just have to find the time...I am sure it's well worth the effort to do an engine out clean up and replacement of all critical hoses, connections, air system removal...you name it. It's just such a hassle to do it from above, below and sideways Well done!
This is the stainless steel cover I made to house the two discharge units that are mounted on the fire wall next to the Lh fuel tank. Under it is another s/steel mounting plate. The Image is created by a series of 1 mm slots that act to ventilate the units. The sides and base are also vented. This location was the best, and is secured with six nut-serts into the alloy plate, rather than diminish any more of what my wife describes as a useless trunk! There is no cure for this Ferrari stuff is there? Cheers MG Image Unavailable, Please Login Image Unavailable, Please Login
There is no cure for this Ferrari stuff is there? Cheers MG[/QUOTE] I don't think so...and from what I can see your beyond hope! Once you put the dizzy back on you can barely see it , true sign of a total enthusiast BTW...that useless trunk makes a great golf bag warmer.
Very pretty !! Great job, the way its supposed to look Is the underneath the same ? If not, im sure you'll get around to it soon Perfect looking engine bay mate !
Thanks for the compliments guys, the car is a 76 Ausssie delivered Glass Gtb. I like to have the condition of the car capable of standing up to what you would expect from its name. Regards MG
