Dealership fault analysis?

[Dr Loguey]

Aw man, am I out of my depth here or what ....???? Reading through the posts everybody seems to know what everything is called, how it works and how to knock up replacement parts with a Pepsi can and a (Edit). But (Edit), I'll ask my rookie question anyway...

2004 Road King started missing a bit and losing a bit of power temporarily while riding back in April (first big ride-out of the year around start-stop roads but after a few fresh tank-fulls of fuel). It was due for a service in May (20,000 miles) so I mentioned it at the dealership. At the end of the service they said they had put it on the analyser but it hadn't shown any faults and maybe the new plugs would sort it out. On the way home from the service it did the same again and has done on a few occasions since, including during a 320 mile run yesterday when it took a lot of turning to start it after a rest. I've just been brave and checked the plugs which show signs of what my Haynes manual calls 'carbon fouling'.

Now I'm more than happy for you to suggest what my problem might be (apart from my obvious lack of any mechanical knowledge!) and would welcome your advice but I suppose my main question really is, can the dealer's machine really be trusted to find the problem or would I be better taking my baby to a human mechanic? The dealer is expensive, especially if they couldn't diagnose the problem last time and I don't want to keep paying for a machine diagnosis that appears to be no more than a trial & error? Any views?

Thanks,
Loguey



Please read this...

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[Hoople]

they said they had put it on the analyser but it hadn't shown any faults

All the dealer was telling you is that the ECM was clean of any DTC's. Nothing more, nothing less.

The majority of DTC's are only set when an extreme condition is met, meaning the sensor is OPEN or Dead Shorted. Sensors or devices that are their way out or are partially bad usually won't set a DTC. This is were experience and real troubleshooting techniques come into play.

"started missing a bit and losing a bit of power temporarily while riding" is not enough info to determine what is wrong with the bike.

 

[GARVIN]

the problem with intermitent faults is the tech can usually tell what the problem is when it happens . If the problem is not there during test drive it is almost impossible to find. In 35yrs I have test driven many hours with customers only to have no fault found - next day it may act up all day and is easy to find problem .
If it is acting up get it to dealer while it is doing it , try to get tech to drive bike before shutting off. sometimes just shutting down & restart ecm will recalibrate & problem disappears for awhile.

 

[Dr Loguey]

Hi guys, thanks for that. Sorry I'm only replying now but I was suspended for a while - apparently the term I was looking for was 'cigarette end'!!! Some things just don't translate across the pond!

I'm heading up to the local dealer today and hoping to talk it over with them - was away on the bike for a few days (in heavy rain) and same problem and fault code (P0118) recurred many times.

Thanks again

 

[Hoople]

Very rarely can a Tech just plug in a tester and it will say with certainty what is wrong with the vehicle. That is why a service writer asks you what the symptoms are. With the combination of what You say and how you describe the problem(s),,, what the tester says,,, and a test ride,,, the tech along with his prior experience can usually come up with a diagnosis.

Saying "it did the same again" & "it started missing a bit and losing a bit of power temporarily" doesn't give anyone much to work with. A P0118 "occurred many times" in the rain meaning you cleared the code and it came back many times? You did not talk about if the bike was factory stock, what mods (if any) were done to the bike, the conditions (incline, steady cruise, acceleration etc) the bike is under when the problem happens, if the fuel mileage has suddenly fallen, EFI-carb,,piggy fueler,, etc.

What may help the dealer find your problem quickly is telling them what unique conditions the bike is under when the problem appears. Hope you get it ironed out.