Misfire and running rich

[Panda1404]

Hi everyone,  new to the forum but in need of some advice.  I recently bought a 2003 14, and it's had a running fault since I got it, it was cheap so thought it worth a risk. Anyway to start, found a broken pin in the ecu so got that fixed and tested, just the same tried coils from a friend's bike,  same story,  it had the clutch switch bypassed, fitted new switch,  balanced the throttle bodies, checked compression all good, new map sensor. Always seems to be  missing on number 2. Swapped injectors 1 to 2  just the same. It runs very rich with the occasional flame out the exhaust. Has anyone else had this problem?

[Hooli]

Check the oil temp sensor. I've had them go to a massive resistance & make the bike think it's living in the antarctic so it's rich as hell.

[GSXKING]

G'day mate & welcome to this rich resource of all manor of information & people that are happy to provide answers to your questions 👍👍

[grog]

Panda, strange, only rich on number 2. Im thinking about it. After a run, measure exhaust temps. Faulty spark plug?

[Mick_J]

Welcome to the forum Panda.  Where are you?

[Panda1404]

Hi there I'm in Newcastle upon Tyne, Thanks for replying, the miss seems to always be number 2. I thought it could possibly be the oil temperature sensor? If this is disconnected it runs worse, it doesn't put the FI light on when everything is connected and doesn't have any stored DTC's apart from when things have been disconnected. It's had new plugs, I've tried coils from a friend's bike of the same year, I'm running out of things to try without spending a fortune on sensors.  The only thing I can think of is possibly valve clearance but compression is good and equal across all 4 cylinders

[Horse]

Hi , how do you ascertain that it is no 2 cylinder at fault ? Is the spark consistent on that cylinder ? Is it worse under load , high speed ? Have you checked the TPS value through full throttle opening .Electrical issues usually are worse under load i,f you can make it worse / better under different conditions it may make it simpler to diagnose , after the ECU repair can you be sure it's OK if you can verify consistent fuel ,spark, and compression is ok then I would be looking at engine management and it's inputs

Good luck

[Panda1404]

Hi horse, no.2 exhaust header isn't getting as hot as 1,3&4, also if no.2 plug cap is disconnected it doesn't make a difference to running but can be heard arking when removed.

[Hooli]

Put something like Acf50 on the plug threads and washer then wind it in and out several times.

I've had corrosion on the head give the plugs a bad earth and cause poor running.

[Horse]

So its consistently running on 3 cylinders , is the plug wet when you take it out, if so and it is backfiring / flame out the exhaust its a timing issue , you have swapped that plug with another cylinder? I have had a faulty new plug before , very frustrating, if you confirm the plug and electrics and it has good compression and the plug is wet with fuel it doesn't sound like cam timing I would be looking at ECU as once the pickup is triggered the spark timing of an individual cylinder I believe can only be thrown out by the processor ,try your mates ECU to take it out of the equation.

[grog]

It only always runs on 3 cylinders? If no. 2 not working, theres youre backfiring, fuel going thru cylinder, not burnt but spilling into exhaust. As to why not working??You seem to have covered all bases, sparking at wrong time? Intake air leak? Spray some carby cleaner around inlet manifold to check if a leak. As to spark timing,14 uses wasted spark system, 2&3 always fire at same time except one is always compression the other exhaust. If it was wrong, no. 3 wouldnt be working and it is. Another check id do is a running compression test. Have had a mystery like yours before, turned out a broken valve spring. Comp perfect cranking but not running. Just my thoughts.

[Hooli]

Yes 14s use wasted spark, pots 1 & 3 then 2 & 4 are pairs for it as they share coils.

My understanding of the spark timing is it comes from the crank & cam sensors so is shared by all pots.

[J16SDA]

Mine was running fine for the 1st hour then started misfiring and ran rich. Did all sorts to fix it and in the end it turned out to be the TPS. Changed that and she's running perfect. When I touch the TPS wiring it spluttered so the issue was the wiring for me.

[Daaef]

My K7 has been doing something very similar since picking it up in Nov and going on a few short trouble-free rides.

It started running really rough and cutting out at low revs after a long ride and was running really rich. I did a service and replaced plugs (all 4 indicating running rich), cleared out the tank and replaced the teabag and high-pressure filter and regulator as they weren't great. Still no better. Swapped IAP and IAT sensors and came good so bought a genuine IAP and was running great again for about 200km and now running rough/rich and cutting out again.

Clutch switch is a bit finnicky so removed and sprayed with contact cleaner as well as connector in headlight. Have a replacement on order.

From reading about I guess next to check is TPS and maybe the oil temp sensor?

[KiwiCol]

When you start it does it do the fast idle then ease back to 1100?