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?
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.
G'day mate & welcome to this rich resource of all manor of information & people that are happy to provide answers to your questions 👍👍
Panda, strange, only rich on number 2. Im thinking about it. After a run, measure exhaust temps. Faulty spark plug?
Welcome to the forum Panda. :onya: Where are you?
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
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
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.
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.
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.
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.
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.
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.
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?
When you start it does it do the fast idle then ease back to 1100?
When was the last time the throttle bodies were synchronised?
Mine was doing the running rich pop bang cut out thing. I could ride it the next day with no issues. Then it would decide to play up again. Had to hold the throttle at 3000rpm just to stop it stalling. Was a real pain took me an age to sort it. I believed it to have been wiring connectors inside the headlight. I replaced the clutch switch, made no difference. Hasn't missed a beat since.
Remember your probs Col, reckon i might as precautionary, unplug & spray every connection in there.Running fine but want to keep it that way.Good suggestion 👍
I've known two 14s with long term running rich issues that were a bugger to find, both were the oil temp sensor. The fast idle always worked cause the ECU runs on a timer after checking the oil temp at start up (the timings are in the workshop manual).
It's an easy one to check. There's a two wire plug running up the RH side of the airbox, black & black/white wires I think, just measure the resistance between them. There's a chart in the workshop manual & values so you'll know roughly what it should be. The ones I've seen fail should have been about 100 KOhms but were 1,000 KOhms. I think it was KOhms, but it was deffo that far out & doesn't cause a FI light as that just checks the sensor is plugged in.
Another thought. The ends of the plug leads rot, sometimes it's worth pulling the plug caps off & trimming the leads slightly. That'd cause a weak spark & apparent rich running as it's not burning the mixture properly.
Quote from: Hooli on Thursday, 06 February 2025, 07:04 PMI've known two 14s with long term running rich issues that were a bugger to find, both were the oil temp sensor. The fast idle always worked cause the ECU runs on a timer after checking the oil temp at start up (the timings are in the workshop manual).
It's an easy one to check. There's a two wire plug running up the RH side of the airbox, black & black/white wires I think, just measure the resistance between them. There's a chart in the workshop manual & values so you'll know roughly what it should be. The ones I've seen fail should have been about 100 KOhms but were 1,000 KOhms. I think it was KOhms, but it was deffo that far out & doesn't cause a FI light as that just checks the sensor is plugged in.
just checked mine as it also appears to be running rich.
The manual says you need 4.5-5.5V with the ignition on at the wire TO the sensor. I have 4.77V there so all good there.
With ignition off, resistance FROM the sensor should be 61.3k Ohm at 20deg C oil temp. Currently here it's 34deg C ambient, bike hadn't run in 24h, so I assumed oil would be at around similar. I got 31.8kOhm at the sensor. As a check, I got an icypole out of the freezer and put that on the sensor top whilst checking resistance. This sensor has an inverse relationship between temperature and resistance (i.e reduced resistance as temperature increases). I watched the resistance slowly count up as my icypole sat on the sensor. This confirmed that the sensor is reading correct. I need to recheck when ambients are a bit lower, but I think I've ruled out the oil temp sensor for now. Next on my list is injectors.
Quote from: KiwiCol on Thursday, 06 February 2025, 09:44 AMWhen you start it does it do the fast idle then ease back to 1100?
Yep, the fast idle and then drop to 1100 is fine albeit running rough
Quote from: Eric GSX1400K3 on Thursday, 06 February 2025, 11:26 AMWhen was the last time the throttle bodies were synchronised?
Good question, don't have the service history and I haven't done it since picking it up in Nov. Would be worth doing.
Quote from: Kiwifruit on Thursday, 06 February 2025, 03:03 PMMine was doing the running rich pop bang cut out thing. I could ride it the next day with no issues. Then it would decide to play up again. Had to hold the throttle at 3000rpm just to stop it stalling. Was a real pain took me an age to sort it. I believed it to have been wiring connectors inside the headlight. I replaced the clutch switch, made no difference. Hasn't missed a beat since.
Thanks I'll recheck these connectors. I did clean and reconnect the LH switch block connector when I did the clutch switch
Thanks brains trust for all the input. Will start with the oil temp sensor and go from there.
Quote from: Daaef on Friday, 07 February 2025, 12:31 PMQuote from: Eric GSX1400K3 on Thursday, 06 February 2025, 11:26 AMWhen was the last time the throttle bodies were synchronised?
Good question, don't have the service history and I haven't done it since picking it up in Nov. Would be worth doing.
If you're going to sync the throttles do it before resetting the TPS, or it'll need doing again afterwards.
Just had a thought.
Check all the vacuum pipes as they are known to go brittle & split which results in poor running at low revs/throttle.
Quote from: Hooli on Friday, 07 February 2025, 06:50 PMJust had a thought.
Check all the vacuum pipes as they are known to go brittle & split which results in poor running at low revs/throttle.
Good shout buddy I'd forgotten about those too
Quote from: Eric GSX1400K3 on Thursday, 06 February 2025, 08:59 PMWith ignition off, resistance FROM the sensor should be 61.3k Ohm at 20deg C oil temp. Currently here it's 34deg C ambient, bike hadn't run in 24h, so I assumed oil would be at around similar. I got 31.8kOhm at the sensor. As a check, I got an icypole out of the freezer and put that on the sensor top whilst checking resistance. This sensor has an inverse relationship between temperature and resistance (i.e reduced resistance as temperature increases). I watched the resistance slowly count up as my icypole sat on the sensor. This confirmed that the sensor is reading correct. I need to recheck when ambients are a bit lower, but I think I've ruled out the oil temp sensor for now. Next on my list is injectors.
Hmm. Seems like mine might be ok then. Measured 32k Ohm when engine not warmed up (not completely cold either) and then when warmed up to the point when the oil cooler fan kicked in it dropped to 1.8k Ohm. This indicates to me its working as expected
When I had a problem with the oil temps sensor the readings were very out.
As an estimation from the graph in the manual it's about 100k Ohm at 0c, I was seeing over 1,000k Ohm.
Quote from: Hooli on Monday, 24 February 2025, 08:22 PMWhen I had a problem with the oil temps sensor the readings were very out.
As an estimation from the graph in the manual it's about 100k Ohm at 0c, I was seeing over 1,000k Ohm.
at least you still got an Ohm reading, as a fully failed sensor would read infinite resistance. Been o/s for the past 8 days, hope to get some shed time in soon.
Quote from: Eric GSX1400K3 on Wednesday, 26 February 2025, 07:32 PMQuote from: Hooli on Monday, 24 February 2025, 08:22 PMWhen I had a problem with the oil temps sensor the readings were very out.
As an estimation from the graph in the manual it's about 100k Ohm at 0c, I was seeing over 1,000k Ohm.
at least you still got an Ohm reading, as a fully failed sensor would read infinite resistance. Been o/s for the past 8 days, hope to get some shed time in soon.
Aye but because I got a reading I didn't get a FI light for it. As it pretty much just tests something is connected. There's no logic such as oil temp & intake temp are so far apart it's illogical.
I had that running rich problem in my 14 ten years ago.
Finally I found it. It was poor grounding of ECU..
Also the other groundings were poor. battery-engine-throttle bodies, but ECU was the reason.
Thanks for all the advice - turned out to be TPS/STPS and air filter on top of the previously mentioned IAP sensor.
Wish I'd read the posts about the Hiflo filters before buying one but at least could return it before going OEM.