XJ6 Running Issue

[CallorFold]

The initial message was deleted from this topic on 24 March 2022 at 16:34

[Krikkit]

I'd definitely check the fuel filter etc, perhaps some crap got lodged in there and is choking it out. You'd be amazed how little fuel they need at idle.

[MotorsportTom]

I'd agree sounds fuel related especially if you have swapped plugs etc.

Is it possible there was some crap in the tank you have disturbed while getting it off for the service and the act of it has dislodged it and allowed for it to go through the filter/injectors?

[Auntieroll]

Sounds fuel related ,has pump wiring been disturbed ? Check plugs and sockets for corrosion etc
If there is a filter in the pump in/outlet check that , then check filters in injectors if it has them as they are usually a lot finer than the one in the pump.
A poor wiring connection would be the prime suspect though.
HTH

[dern]

You haven't trapped a fuel line or a breather hose putting the tank back on have you?

ETA, sorry, you said you've checked them.

[gavgavgav]

CallorFold said:

I was convinced previously that it was the breather as opening the fuel filler cap and running the engine worked the first time I tried it (but then subsequently failed, so just a fluke I concluded). The intermittency of the issue definitely doesn't help

Fuel tank will be stripped and checked at the weekend so I'll report back then

This is exactly the symptom I had when I had pinched the vacuum hose to the tank tap, which I did when re-fitting the tank. Vacuum was cut randomly shutting off the flow of fuel.

[poo at Paul's]

I agree on things like vac pipes, but also check out that if you have a quick release connector on any fuel pipes, that the connector is seated right and even if it is, they can go faulty (plastic) and malfunction even if they don't leak. So maybe try a replacement if it is suspect.

[Krikkit]

gavgavgav said:

This is exactly the symptom I had when I had pinched the vacuum hose to the tank tap, which I did when re-fitting the tank. Vacuum was cut randomly shutting off the flow of fuel.

Would it have a tank tap being an FI bike?

[Krikkit]

Is it tricky to remove the injector pipework? Might be worth pulling that off and giving it a clean through.

[Auntieroll]

The pump filter(s ?) Are usually 5 micron compared to the injectors 2 micron so even though the pump filter is clean some crud may well have migrated to the finer filters.

[Krikkit]

I was just about to suggest blowing it all clear with compressed air, you should be able to clean the injector ports up quite well that way too.

I've done that in the past with a couple of car injectors that got full of crap, but thankfully the inlet was on the front of the engine, so access was a doddle

[gavgavgav]

battery terminal loose?

[MajorMajor76]

Sounds electrical and fuel pump related from the error codes, might be worth checking/swapping the fuel pump relay and triple checking the connector and wiring for corrosion/ breaks.

[MajorMajor76]

CallorFold said:

I've had a look through the XJ6 manual and cant find any mention of a fuel pump relay - https://www.manualslib.com/manual/611337/Yamaha-Xj...

There's a starter motor relay, and a fuel injection system fuse, but no fuel pump relay from what I can see. No reason to suspect the fuse though as each time the bike is switched off and back on, you can hear the pump prime every time without issue.

No.29 on here? https://www.fowlersparts.co.uk/parts/6473408/xj6s-...

I'm guessing myself, though. You'd probably need the workshop manual rather than the owner's manual to identify it, I'm fairly sure it will have one. There's still the possibility of a break in the wiring or corrosion or damage to a connector or maybe even something as simple as a bad earth.

[Krikkit]

Great result, definitely sounds like the grips themselves, what else were they connected to?

[MajorMajor76]

Pleased for you that it's sorted. It did seem a coincidence that this occurred right after fitting but it looked like you had checked everything (clearly, apart from taking them off completely!). Assuming they wouldn't be affecting the draw on the battery (did you check the state of the battery, I can't remember), can only really be something like connecting the grips is interfering with the main electrical connections somehow.