Coil on plug - Page 1
Forum section: electronics / general

author: Baliszoft
author_rank: Frequent Contributor
timestamp: October 19, 2012, 05:01:41 pm
content: I thought i would share these pictures with you. Nothing much can be seen as the thing was completely potted (of course).

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2012, 06:11:29 pm
content: I did take one apart recently. A lot of work to get it open, though the 200turn primary was easier than the still potted when it went to the scrappie secondary.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 19, 2012, 07:01:50 pm
content: Ok, what is it and what is its natural habitat? I can't place the first 2 pictures and the last 2 look like a transformer on a stick?

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2012, 07:15:14 pm
content: Coil per plug ignition on a car. Very common on higher end models as it enables higher spark energy and as well allows multiple firing pulses per ignition event. This allows weaker mixtures and thus better fuel economy. Multiple firing cycles at low RPM makes for easier starting, which is needed on stop start engines so as to allow starting with only a half turn of the flywheel.I was in traffic last week next to an 1D10T in a bluemotion, who went through around 50 start stop cycles at a red light moving his german tank forward 5cm at a time as he was busy texting ( right outside the metro police HQ, with one in the lane next to me doing the same) and letting the brake off and then stopping when the car started and moved. Make a note never to buy one of those vehicles used, they will be utterly worthless and nickel and dime you to death when out of motorplan. I will stick to a car with less than 10 electric motors in it.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 19, 2012, 07:30:10 pm
content: Quote from: SeanB on October 19, 2012, 07:15:14 pmAh, that explains a lot. I guess you must have seen one to recognise what it is.Thanks SeanB!

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2012, 07:35:23 pm
content: If you owned a VW made between 2000 and 2010 you will be intimately familiar with them........ And the symptoms of a failing one. Ok if it goes open, but expensive if it goes dead short.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: October 19, 2012, 08:23:42 pm
content: Quote from: PA0PBZ on October 19, 2012, 07:30:10 pmThats probably my fault, i should have mentioned that. Also forgot to take photos of this still intact.

author: baljemmett
author_rank: Unknown
timestamp: October 19, 2012, 09:40:29 pm
content: Quote from: SeanB on October 19, 2012, 07:35:23 pmHeh. My 2004 Seat (with the 1.2l three-pot) has only given me trouble on one occasion -- about a year ago, just pulling onto a 50mph dual-carriageway, I was rewarded with a sudden jolt and a dashboard that lit up like a Christmas tree to warn me of a fault. (Because obviously when you lose one cylinder out of three and the thing goes into limp-home mode, you really need that extra hint that there's something amiss) Anyway, as you imply, one of them going open is hardly an uncommon failure-mode according to the handily-nearby garage.Various comments online suggest that once an engine's eaten one, it develops a taste for them. Touch wood, I haven't had another one go on me, so I don't know how much stock to put in that. At least the experience was interesting from an observe-the-engine-management-at-work point of view.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: October 19, 2012, 10:30:18 pm
content: Quote from: baljemmett on October 19, 2012, 09:40:29 pmActually im at my third set in 80k miles (1.8t 20v). Three have been failed, two of them in two weeks. Replaced all four. Now it is starting agsin, so im replacing all four now, so it wont surprise me (also i always carry at least one spare from a previous batch). Luckily they can be swapped over easily, even roadside.

author: amyk
author_rank: Super Contributor
timestamp: October 20, 2012, 05:42:52 am
content: Doesn't sound too reliable...Quote from: PA0PBZ on October 19, 2012, 07:01:50 pmThe shape of the first two and the title made me think it was a potted wallwart.

author: SeanB
author_rank: Super Contributor
timestamp: October 20, 2012, 05:56:11 am
content: Bosch really has a hard time with these. They live in the most hostile environment possible. 400C inside at the plug end, massive vibration from ignition cycles and fast temperature cycling every time you start. All to not have a plug pack outside the engine and 4 wires to lead to the plugs. This design with leads will do the same job reliably.