Subject: Re: Twin Plug Coils Sat Feb 29, 2020 5:32 pm
Well I could get one new coil, and I did. Turns out (jury is still out, mind) the left coil was dodgy. Replaced, and stuffed up a few other things, before I got it right. Thankfully, some weeks back when all this came to a head, I marked the coils. After mixing up things yesterday, and not plugging in the fuel hose properly, the old girl wouldn't even start.
Turns out I had one good coil and one dead (almost) coil, so starting on one cylinder only is a challenge you don't want to go near, but doable if you have patience.
Parked her last night while I cogitated overnight. This morning, I realised how stuffed up I was yesterday. The dead/dodgy coil ended up in the R/H side. Swapped it out today and she starts and idles. Will give some spirit later to see if I am indeed right.
beetle GRiSO Capo
Posts : 9996 Join date : 2013-09-30
Subject: Re: Twin Plug Coils Sat Feb 29, 2020 5:59 pm
Subject: Re: Twin Plug Coils Sat Feb 29, 2020 9:26 pm
Went for a run, and those issues seems to be gone - had a hell of a time starting her after an hour or so. Not clean fuelling in the 4.6/4.7 TPS region - though this was there before, just exacerbated by the dodgy coil.
On reflection, it would have been prudent to shell out for the proper injectors at the beginning of last year, instead of the chinesium ones. I have played much with the mapping over the last year and I may have made things worse for myself in the process. I have taken around 40% out of the main fuel map, and some little bits from the idle and warmup maps.
I might see if I can get the original injectors serviced by an injector mob and retry them with the "stable" map from August 2018.
Well both of us got to work today in most excellent style. THAT problem is solved, with the replacement coil. You don't realise how bad things were until they are bad no more. Must have been a weak/dodgy spark for quite a while as now the old girl has most excellent get-up-and-go-edness. Fuel consumption seems to have gotten better as well. Idling is steady both cold and hot. Started first go this morning. Me happy!
Thanks to all those who suggested causes, loaned parts, advised where other parts could be found. This site is GOOD!
Yeah, nah. As some of you will know, this problem reared its head again, but different. Beetle advised me of a pair of coils from a wrecked Bellagio for sale, these were purchased and one fitted this morning - on the other side.
Things are grim when you have to buy 2nd hand parts. But hey, there were for sale and the new option is probably 3-6 months away. I think I bought the last new unit in Australia a few weeks back. Mario couldn't understand why I would want 2 x coils - because both of them were shot, that's why!
Again, thanks Mark, for your eagle eyes.
Posts : 750 Join date : 2016-02-09
Subject: Re: Twin Plug Coils Sat Mar 21, 2020 3:41 pm
I want o say some impolite words, but I can't even be bothered. So so disappointed, the miss is back! Next step is to put the old injectors back in and restore "the ultimate" map from 18 months ago. Then I'll see where that leads.
If that doesn't fix it, it may well be the ECU. Easy to get out - NOT!
Gaps on the R/H valves was spot on at 0.1 and 0.15. I suspect the L/H is the same - no change over the last few services, so that at least looks OK.
Incidentally, I noticed the spark on the cranking while compression testing - spark jumps around 20 mm from the cap to the rocker cover - I reckon this is good! Wouldn't want to put your old fella in circuit for THAT test!
Oz1200Guzzi Don Abbondio
Posts : 6080 Join date : 2014-03-13 Age : 69
Subject: Re: Twin Plug Coils Thu Mar 26, 2020 12:42 am
Right head is off, cylinder is loose (I'll leave it on until I am ready with new parts). A fair bit of cleaning to do in the meantime... [You must be registered and logged in to see this image.]
This is the low side, compression-wise - 128 PSI
Pete Roper GRiSO Capo
Posts : 10293 Join date : 2013-05-29 Age : 67
Subject: Re: Twin Plug Coils Thu Mar 26, 2020 1:57 am
You can see the oil wash on the top of the piston. There is usually a 'Clean' bit on the squish band on the non-Thrust side but as you can see yours are washed clean all the way to the dome.
Get a valve spring compressor and pull the valves and see if they flop around in the guide. As long as you can barely feel slop from side to side when you hold the valve head 1.5cm they're probably good enough. If they move around like a cock in a sock then they will need k-lining. At your mileage though I'd suggest a full head service and at least new exhausts.
I don't have valves in stock but Mario probably will, along with gaskets Guzzi Spares, my other recommended supplier, has closed for personal reasons and I doubt, but don't know, if PS would have valves in stock. I do have rings on the shelf.
One of the problems at the moment will be supply. If stuff needs to come in from overseas it will take considerable time.
My advice right now would be to check the valve seal by pouring petrol into the ports one by one and looking to see how quickly it leaks into the combustion chamber when you hold the head vertical with the port uppermost. You want the combustion chamber dry for at least two seconds. It will be the exhausts that will likely be the worst.
If the valves check out as sealing OK I'd forget the guides for now. Get gaskets, o-rings for the rocker carriers, (There are two around the oil delivery galleries on the late 2V motors rather than 4, one on each stud like the earlier donks.) and just re-ring it. You can easily pull the heads again in another 20-30,000 km and by then, hopefully, this current clusterfuck will of run its course!