Evo with a cough

So today it developed a intermittent cough
Seems to do it in second gear going through villages trying to keep to 30mph
Sounds like it may spit back up the air box , feels rougher than before the remap
I really do love this bike but it obviously doesn't feel the same about me ,
Any ideas most welcome
Best regards
David

[Dukedesmo]

Spitting back out the intakes is usually too lean, may need a bit more fuel?

[Stevedesmo]

Plus 1, weak mixture

[Luddite]

Don't give up just yet!

A couple of things to check.

Firstly, in your earlier thread you said that, after reinstalling the remapped ECU, you ran it for 10 minutes then turned it off.

The purpose of this exercise is to reset the TPS (throttle position sensor). This needs to be done any time the ECU is disconnected. A dealer can do this instantly using the diagnostic tool but, in the absence of this, the 'warm up' procedure accomplishes the same thing.

Note that it is not the length of time the engine is ticking over that resets the TPS, but the reading on the temperature gauge. You need to start the engine from cold then, without touching the throttle, let it idle until three bars come up on the temperature gauge, then turn off the engine. This could take 5 minutes or 15 minutes depending on the ambient temperature. The important thing is not to turn it off before three bars are showing on the temperature gauge.

So, if there's any doubts that you got up to three bars during your 10 minute run, try doing it again.

Secondly, in order to achieve optimal running, the ECU continuously monitors data from its various sensors to 'fine tune' it's own default settings. It is, to a certain extent, self-learning. There are a number of criteria in the ECU that are progressively fine tuned in this way and these are called 'auto adaptive parameters'.

Now, these optimised parameters can be deleted by a dealer manually or if updated software is downloaded. Also, when a Rexxer map is downloaded, the previously stored auto adaptive parameters are deleted.

Following such a deletion, the ECU can only use its default values until it has again relearned those optimised values.

Symptoms of an ECU that has had its auto adaptive parameters reset include:

• Rough running especially at and off idle.
• A tendency when slowing down for the tickover to hover around 2,000 rpm for a few seconds before dropping to normal.
• The possibility of the motor stalling for no apparent reason.

It usually takes around 100 - 200 miles for the ECU to relearn its optimum settings so I'd suggest you continue to ride as normal and you should see an improvement.

If it's no better after, say, 300 miles, give Neil at Cornerspeed a ring and see if he has any suggestions.

Thirdly, it is possible your throttle bodies might need balancing but see if things improve naturally first before considering any other work.

Hope that helps.

Originally Posted by Luddite

Don't give up just yet!

A couple of things to check.

Firstly, in your earlier thread you said that, after reinstalling the remapped ECU, you ran it for 10 minutes then turned it off.

The purpose of this exercise is to reset the TPS (throttle position sensor). This needs to be done any time the ECU is disconnected. A dealer can do this instantly using the diagnostic tool but, in the absence of this, the 'warm up' procedure accomplishes the same thing.

Note that it is not the length of time the engine is ticking over that resets the TPS, but the reading on the temperature gauge. You need to start the engine from cold then, without touching the throttle, let it idle until three bars come up on the temperature gauge, then turn off the engine. This could take 5 minutes or 15 minutes depending on the ambient temperature. The important thing is not to turn it off before three bars are showing on the temperature gauge.

So, if there's any doubts that you got up to three bars during your 10 minute run, try doing it again.

Secondly, in order to achieve optimal running, the ECU continuously monitors data from its various sensors to 'fine tune' it's own default settings. It is, to a certain extent, self-learning. There are a number of criteria in the ECU that are progressively fine tuned in this way and these are called 'auto adaptive parameters'.

Now, these optimised parameters can be deleted by a dealer manually or if updated software is downloaded. Also, when a Rexxer map is downloaded, the previously stored auto adaptive parameters are deleted.

Following such a deletion, the ECU can only use its default values until it has again relearned those optimised values.

Symptoms of an ECU that has had its auto adaptive parameters reset include:

• Rough running especially at and off idle.
• A tendency when slowing down for the tickover to hover around 2,000 rpm for a few seconds before dropping to normal.
• The possibility of the motor stalling for no apparent reason.

It usually takes around 100 - 200 miles for the ECU to relearn its optimum settings so I'd suggest you continue to ride as normal and you should see an improvement.

If it's no better after, say, 300 miles, give Neil at Cornerspeed a ring and see if he has any suggestions.

Thirdly, it is possible your throttle bodies might need balancing but see if things improve naturally first before considering any other work.

Hope that helps.

Wow , yes it hangs on before dropping to tick over , yes it stalls unexpectedly, will try running up from cold on Rickover as it was freezing cold the day I did it , what a fantastic piece of information! Top man 👍, really do appreciate your help , best regards David

Also tickover not dropping straight down isnightmare in hairpins , have to pull clutch or she'd put me off the road �� As speed to high to negotiate bend !

[Luddite]

I just had another thought: did you disconnect the lambda sensors? The Rexxer map is designed to run without lambdas. If they are still connected, they will mess with the fuelling so make sure they are unplugged. A bit of silicon grease in the plugs/sockets to protect them from moisture is recommended. For a proper job, make up blanking plugs with parts from here: http://stores.ebay.co.uk/3waycomponents/ (10% discount for members).

If you want to physically remove the sensors, you can get some stainless blanking plugs from here: http://www.ebay.co.uk/itm/122483544551

The connector for the front cylinder is under the tank on the right just behind the fuse box (no need to lift the tank). The one for the rear cylinder is under the front of the saddle on the right inside the subframe arm.

[Tim88]

Facinating input from Luddite. Should the three bar warm up process be used following a battery replacement to reset TPS? I have had that strange 2000rpm hang up situation (felt a bit like a manual choke being left on), following on from an unexpected stall which had left a strange display of random looking characters on the dash. The thing was confused for sure. All got better on its own after a few restarts, so looks like learning is taking place (for me and Evo). Wish I knew more about what the ecu is doing!

That is one really neat post from Luddite, well worth a sticky I,m sure.

[Doggy]

Totally agree.

The man is an encyclopedia of knowledge!

Yes disconnected them and fitted nice blanks , and made blanks for wiring connectors, once again your thought process is impeccable, I really do appreciate your time , very highest regards David

[Luddite]

Thanks for the comments, guys. Glad you're finding this stuff useful. I've learned a lot from this forum over the years, it's nice to be able to put something back in occasionally.

Just to expand on the "self learning" function above, this only applies to the ECU settings that govern low speed/small throttle openings. In other words, where the lambda sensors would have been working prior to the remap. That's why, when the auto adaptive parameters are deleted, it's the idling and low speed running that suffers.

Consequently, if you do a lot of town work, the auto adaptive parameters will sort themselves out quicker than if you're heavy on the throttle everywhere or do only high speed runs.

Originally Posted by Tim88

Should the three bar warm up process be used following a battery replacement to reset TPS?

Tim, the workshop manual says the TPS must be reset each time the ECU is removed/replaced. Strangely however, it says nothing about performing a reset after replacing the battery.

But how does the ECU know it has been replaced? It can only be either from losing the battery voltage or by losing the connection with the dash. Since the 'warm up' reset is so quick and easy, I'd perform it any time the battery was disconnected, just to be on the safe side.

As far as storing the auto adaptive parameters is concerned, the ECU needs a constant voltage to maintain these in its RAM. Consequently, disconnecting the battery will definitely erase them and you'll suffer glitchy low speed fuelling for a few miles until the system relearns the optimum setting.

This must be common on most ECUs as I read about this same thing just the other day in the Haynes manual for my 1997 Skoda Felicia. (I know, I know, but how else do you think I can afford all that carbon?!)

The more I learn from you the more sence this makes , my normal Sunday blast up to Kielder involves very little town style riding ,, but as the road turned wet last Sunday I turned round and just followed my nose on any dry roads I could find , this involved lots of villages and stop start riding . That's when the problem became apparent , you'd make a good detective, I've disconnected my ecu and battery , going to start from scratch this weekend and do the warm up procedure again . Can't thank you enough, very best regards David.

I disconnected my ECU recently to do some troubleshooting and it's been fine without having to do the 3 bar warm up.

Originally Posted by markh

I disconnected my ECU recently to do some troubleshooting and it's been fine without having to do the 3 bar warm up.

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