Hi,
As my car is 17 years old, and has done less that 40,000 miles and is garaged, I thought this is worth asking. I don’t have any obvious problems with engine performance, and there are no OBD2 error codes showing BUT does anyone know whether the “coil-on-plug” units or leads used on the 2003 1.8 VVT engine tend to wear out or need replacing after this length of time?
For this engine there are two HT coils, mounted on two of the plugs, and each coil has a short HT lead to the other plug.
If they do wear out, does anyone have a recommended supplier?
Cheers
Same car here except 2002 which we own and have done for 15 years & 60,000 of it’s 105,000 miles.Frankly, I’d say don’t give them a thought. Only last year (!) we replaced ours at circa 104,200 miles as one (or both) started causing misfires. I just changed them both for safety as I did not want my wife getting an issue when driving alone, but only 1 was actually dodgy…perhaps a dry joint or summat.
They are not cheap so I would say wait till, if in your case ever, they do cause an issue which is less likely with such low miles. You would soon know with pops & bangs and 2 pot running. Basically they are either in…or out! NBFL engine leccies seem extremely robust & reliable, in my view remarkably so.
Hi,
Thanks very much for both the prompt reply and the voice of experience ! I was hoping it was the case that “if it’s working leave it alone”, and as you say the electrics all round have been very reliable. I guess my query goes back to the days of contact breaker distributors whre I seemed to be adjusting the gap or cleaning the points every few months…
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Frankly I’d go back to the days of plugs, points, condensers & rotor arms & dizzy caps.
At least we could fix it from Halfrauds & a cuppa char in 15 minutes.
Kept a few engines sweet with a bit of emery paper & rubbing the rotor contacts on a sidewall! 
b
Back in the day when brekky was a broken bowl of gravel & a tin mug of gutter water to wash it down eh?
Harrumph!
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Quite agree it was easier to fix a problem when electrics were simple and parts were cheap enough to try swapping something just in case, but I bought a Lumenition contactless ignition module in about 1979 and I was converted to that level of tech. The problem now is that the electronics are so complex that when something does go wrong it is difficult to work out what the the real problem is- and it is too expensive to swap entire units just to try something out
Anyway thanks for the info but in the current lockdown I won’t be going out in my MX-5 for a while…
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