[motomo]

I have a 2002 Megane Classic 1.4 16v. Idles rough and no engine power, it does start, but when I check which coil is faulty found 2&3 not working. Already put new plugs and coils but still no spark on cyls 2&3. I even tried coils 1&4 swapped with 2&3 and still no spark on 2&3.
Already checked the wiring from connectors to power box and ecu and seemed fine.

Found some schematics on the web for the ecu and still have to check if there is voltage from ignition switch to the coils.

Could it be the TDC sensor? only for 2 cylinders?

 

[danthevan]

I would say one of 2&3 will be firing, as it's near on impossible to get a 4 stroke engine to run on 2 cylinders.

Are you unpluging the coils to track down the problem or the injectors?
I believe the coils are wired as pairs, so if you unplug one, you lose 2

I'd be more inclinded to think it's either a duff injector, or a dropped valve resulting in no compression on one cylinder

 

[motomo]

I'm actually taking the plug out and pressing it against the block and start the engine and check for sparks, the engine is idling with just 2 cylinders going (1&4).
The plugs are coming out wet on gasoline, so the injectors would be fine.

It makes no difference if I unplug coil 2 or 3 or both. It's idling with just 1&4. The exhaust smells like fresh gas so I believe the injectors are fine.

But still no evidence of sparkling on cylinder 2&3 which work together.

 

[motomo]

Found the problem on the ECU. A track on the flex circuit went off. Easy repair to solder a jump wire from the socket to the power transistor.

It needs some wire follow and measurement of continuity on the wire harness to find out the pins on the ecu socket.

 

[danthevan]

Always nice to find the problem!
If you dont fancy repairing yourself, i'd recommend the ecu doctor. They'll repair your unit without losing any of the info held in it for a sensible price

 

[AkAntA]

I'm having similiar problem right now. Mine coils are 1&4 that aren't working. Though I can't find the error through measurement of continuity. Could you provide me with those schematics Motomo?

 

[Nottnoc]

I doubt Motomo is around, his last post was almost 4 years ago.
Also publishing Schematics is a No No on here, unless you drew it yourself.
Sorry.

 

[AkAntA]

I doubt Motomo is around, his last post was almost 4 years ago.
Also publishing Schematics is a No No on here, unless you drew it yourself.
Sorry.

Yeah I was kind of thinking the same that they wouldn't be here anymore.
I didn't know that publishing of schematics is banned here. I might sound stupid asking this but why is it so?

Anyways. Does anyone has any ideas for this problem now that I doesn't seem to have problem with broken circuits?

 

[Nottnoc]

Simples, Copyright & the fear of being Sued.

 

[mickeybo]

Can you post up your engine code