(solved) 97 Daytona T595 Misfires Past 4k Rpm

Sounds like an airflow or air temp measurement problem so check those two sensors.

 

Get yourself one of these cables if you can https://www.lonelec.co.uk/Motorbike...onent/TuneECU-Interface-Cable-Lead-Diagnostic
It’s the one recommended for Tuneecu and reportedly the most reliable connection.

 

As Tricky-Dicky says, those sensors could be faulty. It could also be coil related with one or more breaking down when hot. Unfortunately the only way to check that is to swap out the coils.

 

Nice to hear of another 97 T595.
Have you carried out any of the mechanical mods?

 

Hi Guztaw, I'm with the other people who suggest a coil breaking down, I've had a few break down with symptoms you describe, you can pick up a S/H one fairly cheap from the internet, sandys spares for example. Hope you sort it soon.

 

Yes it could well be coils and i hope it is but coils usually brake down when the engine is loaded and it would be unusual for all to do so at the same time at the same RPM range ....engine heat does cause the insulation to eventually brake down and then the HT leaks to earth and will cause a misfire.

The fuel injection works by referencing the air pressure/flow against RPM/load and uses air temp to scale the map but if temp sensor is faulty the default is to run fueling on the rich side for safety and if airflow scaling is out there is a similar result scanning the ECU for fault codes is really the only way to diagnose for sure.

 

Sounds like the classic Triumph coil failure to me too. ...J.D.

 

Let us know how it works out please. ...J.D.

 

The stick coils on these are really not that unreliable (compared to say the older carb models or twins). Also unlikely that all three would suffer all at the same time and same symptom, OK when cold then all of them breaking down at temp.
More likely than coils I suspect would be the crank position sensor
First off, check it's gap - should be 1mm
Then also check its resistance (I'll have to get back to you on that value tomorrow) - but you can at least compare resistance when it's cold and when its hot and has the problem.

 

I was asked in PM about the effect of sensors - replying here so others can comment.

You have three sensors that affect fueling
1. The Engine (Coolant) Temperature Sensor - that one of course delivers a different temperature as the engine goes from cold to normal running temperature, but will still trim accordingly for the differences of normal high speed running (probably mid to high 80's), vs slow & go in traffic closer to 100)
2. The Air Temperature sensor - this one is going to change less on any given day and biggest effected change would be in cold morning weather vs peak heat of the day. - in slow and go it can also be pulling hotter air from radiator and will account for that.
3. The Atmospheric Pressure Sensor - this is going to vary depending on the atmospheric conditions - weather and altitude will make significant changes on any given day - for example where I live, I can go from sea level to 10,000 ft and back in a single day trip - air is much less dense at higher altitude.

It's doubtful (but not impossible) that any of these would be a 'hot' factor where problem only shows up after 20-30 min running - the best way to check these is by connecting TuneECU and getting direct reading on-screen
You didn't mention, so expect there is not - but presume you have no MIL (check Engine Light) when this problem starts to happen?

Other possibilities that would be more prevalent at higher engine speeds vs - Fuel Delivery (low pressure from pump) or not enough air - blockage in the airbox - would not be fist time an air box has been opened to find mouse nest in there!
Difference after 20-30 mins would be odd however for either of those, although could certainly be fuel pump issue that stops delivering full pressure after running for some time - the regulator itself is a mechanical device and won't be affected by time or temperature.

You also asked about faulty gapped plugs - first question is, did you recently replace them and if so, was this in order to address the problem or did problem only happen after you changed them?
If you haven't changed them, have you inspected them? What colour are they?
Pull them when you change the coils, ideally post an image of what they look like.

 

The fact that the engine only runs well between 2k and 4k RPM says to me there could be a problem with the crank position sensor or possibly the TPS is out as the ECU uses RPM vs air flow/pressure and TPS for load the other sensors are just for scaling of global fueling.
At those RPMs/load the fixed map will be active so if overall scaling is out it could also effect ignition advance/retard as there should be secondary fallback maps for ignition advance linked to load.