Reading Spark Plugs... August 02, 2020, 08:43:07 PM Looked at the various comparison charts etc. thrown up by Google, but thought one of you genuine mechanics could give an opinion on the health of this plug.Took a stack of different photos, but this is the only one that was clear enough to post, I wouldn't have choosen it otherwise as the plug actually looks a lot less black and more a light brown in reality. (If you're on a PC, right click and view image, it'll magnify a little.)
Re: Reading Spark Plugs... Reply #1 – August 03, 2020, 11:18:41 AM Going to stick up one of the poorer images regardless, the one above doesn't really show the plug as it is.The reason I'm asking is that when I got the 205 it had an aftermarket adjustable fuel pressure regulater in place of the fixed 3.0bar standard one.Took me a while to realise it and after a bit of looking found out it's a Sytec FSE item.They're still available, though I'd guess the one in the Peugeot was added a very long time ago.https://www.merlinmotorsport.co.uk/p/fse-adjustable-fuel-injection-pressure-regulator-8mm-tails-air004?utm_source=Google&utm_medium=ShoppingUK&utm_campaign=ShoppingUK&vat=on¤cy=GBP Apparently they need checked periodically and adjusted as necessary, that requires a specific mechanical gauge that came with it (and I don't have) plus a bit of know how as to what you're doing and I don't want to get into messing with fuel mixtures etc.There's also talk that they can be unreliable, though in fairness the Pug's been running like a dream since I've had her.If I've understood correctly the FSE item is variable up to 5.0bar... I've no idea what mine was set to.I found an original 3.0bar Bosch replacement, you can buy new 'copies' at a fraction of the price but that may well be for a reason? The upshot is I decided to change it out... the fuel pipes were being done and it was sensible to do it all at one go.There's absolutely no change to the way the engine runs, still perfectly.The pic. of the plug (new in about 1000 miles ago) shows it between changes... Curious to know if the FSE was having any unintended effects. Last Edit: August 03, 2020, 11:20:26 AM by L90E
Re: Reading Spark Plugs... Reply #2 – August 03, 2020, 06:32:22 PM Looks healthy to me, not oily, not white, not black, brown is good, bit of carbon but to be expected.
Re: Reading Spark Plugs... Reply #3 – August 04, 2020, 11:21:33 AM Cheers Bill... Usually I wouldn't fix what isn't broken, but there were a few things I wasn't happy about with the FSE regulator. It sat differently to the standard one, even with it's proper adapter.You could see the mark on the under bonnet insulation where it'd been pressing into it over the years, plus it slightly stretched the short vacuum hose between it and the inlet manifold. I didn't want the same to happen with the new pipe.Good to know though that it was probably set up right.
Re: Reading Spark Plugs... Reply #4 – August 04, 2020, 03:02:17 PM I agree those plugs look ok, but as a side note... and not sure on the effects in cars, but these multi-spark plugs have been found to cause issues in some older motorbikes. Can't remember the science behind it but I have seen a few discussions on various forums over the years where a few owners of 80s sports bikes found the old fashioned single electrode type ran better than modern iridium and/or split-fire plugs. Just something to bear in mind as I don't think this style of plug was around when the engine was designed so safe to assume the set up was designed to work with a single spark.
Re: Reading Spark Plugs... Reply #5 – August 04, 2020, 05:45:16 PM That thought did occur to me as well Eddy as I remember when I had my 87 16V tuned in 1990 they put those plugs in and I hadn't seen them before but I have heard similar stories back in the day of them not being suitable for some applications, never had an issue myself though.
Re: Reading Spark Plugs... Reply #6 – August 04, 2020, 06:41:19 PM Interesting! Will have to try reading up a bit more.Am I right in saying one of the potential causes of carbon build up is an insufficiently 'hot' plug for that particular engine / type of use?Maybe more modern multi contact plugs run cooler than their older single contact equivalents... only guessing.The car, not unsurprisingly, doesn't get as much use as a daily would, plus there's probably a lot more cold starts / stops than usual while moving it around when working on it / in and out of the garage.
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