Resetting an ecu

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gingerrusta
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Post Sat May 25, 2013 9:26 pm

Just an idea but how do you reset your ecu ? Is it just the case of
disconnecting the battery for an hour or so ?
Grrrmachine
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Post Sat May 25, 2013 9:29 pm

Undo the battery clamps and join them together (the wires, not the battery terminals!) Leave for a minute or two.

Why do you want to reset the ECU?
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gingerrusta
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Post Sat May 25, 2013 9:44 pm

Long story but my car hasn't been running well since getting her back on the road recently . As you can probably see on my other post " 325 cabby running rich "

I have been thinking today that my car run lovely before it sat about and the battery went flat a few times by lack of use and the alarm system. So I then change a lot of parts on the engine and thinking that the ecu might be confused with what's going on so instead of guessing what's what I thought it maybe something simple like this that would help. The biggest problem I have at the moment is the revs being too low and the car is cutting out. I'm hoping this will sort it out . Well it isn't going to so any harm is it ?
Grrrmachine
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Post Sat May 25, 2013 10:10 pm

It won't harm it as long as you do the correct relearn procedure. After resetting the engine FROM COLD, start the car up and let it idle for ten minutes. Then turn it off, restart, and take it for a very aggressive drive. That should sort it.
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gingerrusta
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Post Sat May 25, 2013 10:21 pm

How many miles would you say or amount of time driving ? It's an auto so just do it in drive I take it ?
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mark_i
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Post Sun May 26, 2013 7:50 am

one thing also is checking the earth strap between the engine and front chassis leg.
I would say the time for the ECU to relearn settings depends on the engine being allowed to rev though the range, so on an auto, boot the accelerator in 2 to get the revs up to 5000.
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gingerrusta
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Post Sun May 26, 2013 8:07 am

So defo need some motorway blasting through the range. Fingers.crossed this will work and I can enjoy the sunshine in her today
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gingerrusta
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Post Sun May 26, 2013 4:59 pm

Just went out and started her up. She ran for about 6mins on idle and then gradually the idle got worse.
She was going up and down and then cut out so I couldn't even get her to tick over for the full 10 mins.
What shall I do confused.com
Grrrmachine
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Post Sun May 26, 2013 5:01 pm

Unplug your ecu and follow the Blue Temp Sensor test:

http://www.e30zone.net/e30zonewiki/inde ... ug#Testing
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gingerrusta
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Post Sun May 26, 2013 5:38 pm

I have tested the blue temp sensor and replaced already. I just went out in her and she pulls like a train through the gears lovely but its just this blooming idle.
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gingerrusta
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Post Sun May 26, 2013 5:40 pm

I was on the motorway and came to a roundabout and she just didnt hold the idle and cut out
smithysmith
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Post Sun May 26, 2013 7:05 pm

This may sound obvious but have you checked all your vac hoses and cleaned the ICV
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gingerrusta
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Post Sun May 26, 2013 7:15 pm

I have cleaned my icv and checked the hoses and all seems to be ok.
smithysmith
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Post Sun May 26, 2013 7:21 pm

Could the afm be at fault?
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gingerrusta
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Post Sun May 26, 2013 7:42 pm

Just testing throttle position sensor at the moment