Hi to all.

As mentioned in my previous post about idle speed roughness.

Although my car has been conclusively fixed by replacing the crank angle sensor.

My friend brang his ef to me complaining about the same issue, rough idle.
i replaced his too and made no difference to his idle .
It was still rough.

The problem in his car was the ecu.
I didnt need to replace it, I repaired part of the earth system inside the module.

One link was overheated and resulted in a poor circuit to the coil drivers and idle up control system.

The reason for it was a sticking isc valve.

Repaired this and cleaned out the isc motor and is now running like a clock.

If anyone needs the picture of the ecu module and the mod please feel free to contact me.

Yeah pictures of it would be great if you do have them
But basically your saying to clean the isc valve (which is actually what I was going to do this weekend along with the TB), and then repair the damaged earth in the ecu

How did this sticky isc valve damage the earth in the ECU?

I'd be interested to see what you're refering to.

Hi again.

The sticky isc motor has caused an excessive load on the ecu driver.
The earth track that goes to the i.c . has been melted of the board.
Thus causing an open circuit.


This earth leads to the drivers that control both the coil packs and the isc semiconductor driver.


If your car is idling and the handbrake is firmly applied and transmission in drive. open the bonnet and listen to the injectors.
They should be ticking steadily and not irregular.
If they are irregular then this points to the ecu.

Here goes first picture.

With the lid removed this is the underside of the ecu.

Get a multi meter and put one probe on the metal cage of the ecu.

Now if you probe the bottom left hand of the ecu i will read a short to earth, this is normal. which means the earth is sufficient there.

however if you look at the bottom right hand corner of the ecu, the last i.c. is five pin soldered to the board. I.c. reference number marked on the board(ic 35a). This is the driver for the isc motor.

The bottom row pins are three. and the upper row has got four.
Connect a link from the centre pin of the bottom row. This pin should be an earth prior to the ecu getting damaged..

next connect the opposite wire to the earth screw hole, and tighten it.

Now it is possible that the isc driver might be damaged.
In order to prevent a reacurring meltdown, grab a wire and strip the sleeve of it all together and use a single strand of it.

If the driver is crook than this strand will act like a fuse.

plug the ecu to the car with the lids removed and start it.

If the driver is okay then the strand will not let go.
If that is the case then you can connect a permanent shielded wire there.


Ill send some pictures and this should help.

 

 

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And another picture

 

 

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3rd pic.

 

 

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The last picture shows where the link goes.

After using the strand and all is okay, then hardwire it like so.

 

 

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Thats gettin pretty technical. Lucky I'm an electronics tech and got all the bits and pieces for this lol
Might take a look at this on the weekend
Cheers mate good work