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Old 9th October 2019, 14:58   #21
Odd Job
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Do you have super unleaded in France that you could try in your car?

I run my classic Mini on super unleaded as at the moment it doesn't contain Ethanol.
I'm no doubt that it will before long though.
There are a few additives which are available to stop the phase shift problem.
Not sure about the corrosion problem though.

Richard
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Old 9th October 2019, 15:36   #22
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I'll check but I heard tha 98 Ron here has 5% ethanol.
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Old 9th October 2019, 16:02   #23
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I wouldn't be surprised.

I know eventually it'll be in all forms of petrol to a lesser or greater extent.

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Old 11th October 2019, 07:44   #24
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Back to this,
If it is an injecter that has been damaged by ethanol, surely the car would miss behave on startup ? not after 30 odd seconds.

What does the second LAMBDA sensor do on these cars ? I only changed the first one, nearest to the engine.

Pete.
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Old 11th October 2019, 14:36   #25
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I don't think your problem is an injector either. If the symptoms are the same as mine, it's commanded on for far too long by the ECU.

Second Lambda is only to prove the cat is working - it has no feedback into engine parameters. So no value in replacing it.
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Old 11th October 2019, 16:25   #26
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So what is your engine? And what is yours doing? Is it exactly the same as mine?
We have a seco d TF that is perfect, I'm going to put it on T4 and video it and compare it to the one that's being a pain in the butt
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Old 11th October 2019, 19:54   #27
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Mine's a 1.8 - so the same as in your TF. Almost identical symptoms as well, with the added bonus of it sometimes taking a few turns to start, then bursting into life (literally, you're not expecting it to start and suddenly it's spinning at 1500rpm) and taking maybe 3 seconds or so for the revs to come back down to idle.


Interestingly it's fine if there's any sort of heat in the engine - only has to be just enough to move the temp indicator slightly. Oh, and if you blip the throttle (and it doesn't stall), it will sometimes settle back to a higher idle and/or start hunting by about 300rpm (upwards from idle, it's not so far hunted down to the point of stalling).


IACV is new, have got a new cam sensor to try just in case it's an early sign of that starting to fail. TMAP sensor isn't new, but have tried 2 sensors with same results.
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Old 12th October 2019, 07:22   #28
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First thing you should do is get the new iacv set up correctly on a T4. My ZR used to rev up and down on its own because someone had messed about with the throttle idle screw on the throttle body.

What other sensors are there that could be playing up?

Pete.
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Old 12th October 2019, 20:50   #29
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Well it wasn't the cam sensor...there's not much more it can be sensor wise as I'm sure you've already discovered!


Beginning to wonder if the throttle position sensor is possibly implicated though, approximately 50% of the time I blipped the throttle this afternoon it settled back to a 1000rpm idle, the other 50% it went back to c. 700rpm. It also dropped to 700rpm a few times then instantly back up to 1000rpm.


Could really do with a K series expert like Brian giving his opinion as I'm running out of ideas!

I'll stick the pscan on next and grab some live data, and it's probably not a bad idea to get the idle set properly on T4 too.
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Old 14th October 2019, 14:45   #30
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I checked the IACV on my perfectly good running TF at the weekend. With the engine hot, the steeper motor was at 50 steps ! it should be around 25. So I set the bad TF to 50 and will let you know how it behaves.
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