VAG Voils with Y6DC problem with ecu

[e30isking]

Hi there,

Sorry about asking in English but Im from Portugal.

I hope you can help me with an issue I have.

I installed an OMEX 710 Ecu from the UK and some VAG Coils with Y6DC coils on an S38B38.

The issue I am having is that the ECU resets itself and can't start the engine when I torque the spark plugs to the cylinder head. If I take them out, I can see spark and ECU is okay. This problem only happens with the spark plugs torqued to the cylinder head...and that is strange.

I have verified wiring, ground straps, fuses and relays, etc.

Another trange thing is that the car has started and ran some time ago, but I don't know how as I wasn't looking at this situation back then. Nowadays I can't get it to start.

Has anyone seen anything like this before? I have tried everything and no results.

Thanks a lot,
Paulo

[Jens92]

Have you tried to see if you loose the trigger signal or similar when this happens? Might be because of interference from the ignition system perhaps is something I come to think of.

Tried to separate the wiring from sensors with wiring from ignition parts?

I guess you could try to put some extra engine ground to the chassis and to each coil separately to rule out problems due to insufficient ground.

[e30isking]

Have you tried to see if you loose the trigger signal or similar when this happens? Might be because of interference from the ignition system perhaps is something I come to think of.

Tried to separate the wiring from sensors with wiring from ignition parts?

I guess you could try to put some extra engine ground to the chassis and to each coil separately to rule out problems due to insufficient ground.

Thanks Jens92!

I have separated the power wiring from the trigger wiring (using only crank VR sensor 60-2). I have good rpm and no trigger issues except when the spark plugs are torqued to the cylinder head.

If I have them outside and provide them with ground (to the cyl head), I can see spark and all is good. I do not understand the difference it makes if they are torqued or not but it sure turns off the ECU and I can't understand why.

I will try to run a ground directly to the coils and see if anything changes.

Thanks,
Paulo

[e30isking]

I see I posted this on the sale section. This wasn't intended.

Can any moderator move this to the appropriate section please?

[Jens92]

Came to think of another possible cause.
Have you monitored the voltage when you crank the engine? The ecu might get what it needs when the engine has the plugs out but the heavier load when they are inserted might cause a voltage drop so the ecu shuts down?
Could just try with an extra battery and/or a battery charger on.

[Wiell]

What kind of spark plugs are you using?

[e30isking]

Hi!

Thanks for the help.

Plugs are BMW OEM Y6DC.

Battery voltage is good, even while cranking.

Don't really know what to do. Can this be the ECU's fault?

Regards,
Paulo

[St3v3]

Where have you grounded the two grounds from the coil?

[AGsTony]

Have u disabled the built in igniters in the ecu


Tony

[e30isking]

Hi.

One ground is to cylinder head, near the coil and the other is to the main groung, where the ecu is grounded (this ground point is connected to the battery).

Coils is wired like this:
1 - 12V
2 - ECU ground
3 - ECU input signal
4 - Cylinder head ground



Tony: I sent the ecu to the manufacturer (OMEX) and they disabled the internal ignitors.

Another thing I have found is that I can also have this problem (ECU reset) if I have the spark plug out of the cylinder head and I ground the main body of the spark plug (not the spiral part that is torqued to the head, the part above that). I can not understand why this happens.

Many thanks,
Paulo

[Nisse Järnet]

You did have a good ground between the engine and chassis? I would try to ground the ECU and coils on different locations, and maybe other spark plugs as well just to be sure.

[St3v3]

You can ground both coil-grounds on the cylinderhead, maybe there will be less problem that way

[xelerator]

try resistor spark plugs...

[Jens92]

I know that many ppl here use NGK bcpr7es sparkplugs. I use them personally and no problems this far. Ignition gap adjusted to 0.4mm

[e30isking]

Hi there,

Xelerator: Aren't Y6DC resistor spark plugs? Which ones do you purpose I use? NGK bcpr7es?

I will check all grounds as well, thanks.

[e30isking]

This car will be N/A for now

[xelerator]

Hi there,

Xelerator: Aren't Y6DC resistor spark plugs? Which ones do you purpose I use? NGK bcpr7es?

I will check all grounds as well, thanks.

Come to think about it, maybe they are.
But anyways, you seem to be having a bit of problems with the plugs according to your explaination.
You could check for cracks on the ceramics, and other defects.
Or you could just try a new set of plugs, and if the issues remain you can rule out the plugs for sure.

You could try the ngks, the are cheap and proven to work.