Poor spark coming out of Coils ??? Changed Coils and DFI Module but still poor spark?

[vxcalais_01]

On my VX v6, i have some rough idling, with good leads, new plugs etc. THe problems seems to be coming from before the Coil packs ? I have changed the coils and DFI module a few times and when checking the spark to leads, some points fire, some dont, and it erratic. What would cause poor spark to come out of the coils ? ECU, Crank Angle Sensor ?

Thanks.

 

[Cheap6]

Are you absolutely sure that it's an ignition problem? Usually ignition faults don't manifest themselves at idle rather they show up when the engine is under load. If it's only at idle, it's more likely to be something like a vacuum leak, maybe a burnt (leaking) valve, or an injector with a poor spray pattern.

 

[delcowizzid]

the way the coils work to fire 2 cylinders each makes the spark look erratic on the v6's.and one set of plugs fire to ground and the other three fire from the ground into the electrode

 

[VTS5]

What would cause poor spark to come out of the coils ? ECU, Crank Angle Sensor ?

Thanks.

Neither.....

The wasted spark system is an ignition system used with some four-stroke cycle internal combustion engines,This system has been widely used, including such engines as the Buick V6 engine 3800 LN3 (aka EcoTech),a V-6 engine would only need three coil packs instead of six. Each individual coil fires the spark plugs in two cylinders simultaneously, the spark plug in one cylinder on a compression stroke where the power comes from, and the spark plug in the other cylinder on an exhaust stroke.This design halves the number of components in a typical ignition system, while the extra spark, against much reduced dielectric resistance, barely impacts on the lifespan of modern ignition components. In a typical engine, it requires only about 2 to 3kV to fire the cylinder on the exhaust strokes. The remaining coil energy is available to fire the spark plug under compression (typically about 8 to 12 kV).

Look elsewhere for the problem....

 

[vxcalais_01]

I cant think of anything else.... Could it be spun bearings ? I cant think of anything else electrical. Its really rough under load and idle some cylinders not working. Looking at coils its like spark is not coming from coils. What supplies the coils ? Changed dfi as well.

 

[VR38]

Buy a spark plug tester and test the spark if you want to rule that out.

If it ain't spark then it must be fuel.

Fuel pressure test would be the next thing on the list.

 

[Cheap6]

...or engine mechanical. It's got fancy ignition and fuel control systems but it's still an ICE underneath, with all the possible faults that they have had since they were invented.

Compression test?

 

[vxcalais_01]

Yeah, compression test done. It seems strange the link b/n intermittent spark coming out of the coils or mechanical in the engine. Could be looking forever. Might need a new engine etc. just to solve it. I have had 2 mechanics look at it and no one can find it yet after 2 days looking. Will try a new computer today.