Sensor or ECU fault?
Discussion
Got an irritating problem with the Tam.
If I take my foot totally off the accelerator pedal and start to decelerate before changing gear, all is well, apart from the change jarring and making me look like a crap driver.
If I lift off just slightly after pressing the clutch the engine revs up significantly during the gear change, which is not good for clutch wear or my nerves at low speed.
She didn't used to do this and it's not a mechanical problem, so any ideas where to look in terms of sensors or ecu?
Which fuse resets the ecu, as I may start there.
Ta.
If I take my foot totally off the accelerator pedal and start to decelerate before changing gear, all is well, apart from the change jarring and making me look like a crap driver.
If I lift off just slightly after pressing the clutch the engine revs up significantly during the gear change, which is not good for clutch wear or my nerves at low speed.
She didn't used to do this and it's not a mechanical problem, so any ideas where to look in terms of sensors or ecu?
Which fuse resets the ecu, as I may start there.
Ta.
rfisher said:
Got an irritating problem with the Tam.
If I take my foot totally off the accelerator pedal and start to decelerate before changing gear, all is well, apart from the change jarring and making me look like a crap driver.
If I lift off just slightly after pressing the clutch the engine revs up significantly during the gear change, which is not good for clutch wear or my nerves at low speed.
She didn't used to do this and it's not a mechanical problem, so any ideas where to look in terms of sensors or ecu?
Which fuse resets the ecu, as I may start there.
Ta.
My first port of call with this would be get the software hooked up to the ECU and see what is going on.If I take my foot totally off the accelerator pedal and start to decelerate before changing gear, all is well, apart from the change jarring and making me look like a crap driver.
If I lift off just slightly after pressing the clutch the engine revs up significantly during the gear change, which is not good for clutch wear or my nerves at low speed.
She didn't used to do this and it's not a mechanical problem, so any ideas where to look in terms of sensors or ecu?
Which fuse resets the ecu, as I may start there.
Ta.
The diagnostic software is VERY easy to use and free! The cables are readily available or easy to make depending on your soldering iron skills.
Once you can see what is going on with the sensors and ECU you should be able to start diagnosing the problem.
My car played the same game for a while. I lubricated the throttle body linkages properly, replaced the accelerator cable and re-bushed the pedal box which got rid of the problem in the most part. Now I have all the electrics properly sorted it doesn't do it at all!
Feel free to PM me if I can be of any more help.
What makes you think its not a mechanical problem?
Lets play Devils Advocate, and assume its not the tps giving incorrect readings or unbalanced TBs.
IMHO its odd and a bit coincidental that this would be the only situation where it manifests. Coincidental because the revs rising when disengaging the clutch is a natural response from the engine as its going from engine braking to revving freely, right? So why not suspect that what has changed is when the clutch bites, as well as the TPS value?
If it idles nicely when cold or hot, and has otherwise smooth throttle response, doesn't spit when prodding the accel pedal quickly, then to me this would sway attention away from TB/tune/throttle sensor (not that I wouldn't check that first for obvious reasons), and toward a change in the clutch biting point/slip/dodgyslaves making the required pedal timing different to what you are accustomed to before the problem started.
Mine was doing all sorts of weird things before the slave packed up and the plates were also worn.
btw I use the google phone app to check sensors. Much more convenient than a laptop. Wires are permanently routed to the cubby hole, ready to plugin my phone at any moment. Most importantly as the phone is on a windscreen mount the info is in clear view while driving/testing... wouldn't recommend that with a laptop so well worth the £12.
Lets play Devils Advocate, and assume its not the tps giving incorrect readings or unbalanced TBs.
IMHO its odd and a bit coincidental that this would be the only situation where it manifests. Coincidental because the revs rising when disengaging the clutch is a natural response from the engine as its going from engine braking to revving freely, right? So why not suspect that what has changed is when the clutch bites, as well as the TPS value?
If it idles nicely when cold or hot, and has otherwise smooth throttle response, doesn't spit when prodding the accel pedal quickly, then to me this would sway attention away from TB/tune/throttle sensor (not that I wouldn't check that first for obvious reasons), and toward a change in the clutch biting point/slip/dodgyslaves making the required pedal timing different to what you are accustomed to before the problem started.
Mine was doing all sorts of weird things before the slave packed up and the plates were also worn.
btw I use the google phone app to check sensors. Much more convenient than a laptop. Wires are permanently routed to the cubby hole, ready to plugin my phone at any moment. Most importantly as the phone is on a windscreen mount the info is in clear view while driving/testing... wouldn't recommend that with a laptop so well worth the £12.
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