Coil pack failure or spark plug?

[pawson]

The story is a month ago, my car keep miss fire when full throttle accelerate. In the first few days it only happen when on high boost (1 bar). After that even in low boost or turn the booster off, it just keep miss fire or make popping sound. But it runs normal if I step on the gas soft.

So I drive it to the mechanic. They check it for me and said one of my coil pack is dead. Then I find a 2nd hand coil pack to replace the dead one and it work fine. ( for first two days). After that same problem comes out again and I think may be I'm just bad luck to get a crap coil pack I bought. So I return it and change another one again.

The result is same as the last time. It works fine for first 2 days and then miss fire again. Now I'm thinking I shouldn't be that unlucky to get a crap coil pack 2 times and so is that something make the coil pack failure instead of by itself.

By the way, I'm using the NGK Irdium IX spark plug. (BCPR6EIX-11). Is that the right one for the RB25DET? Also is that the gap problem to make it miss fire.

Please help.............

[blind_elk]

Try closing the spark gap a bit (down to 0.8). Just because the plug comes pre-gapped, it doesn't mean that the gap is suitable for the car.

[pawson]

ok, but can U tell me how to re-gap the plug ?

[blind_elk]

Youngsters!

To re-gap spark plugs

1. Buy feeler gauges.

2. Remove spark plugs.

3. use feeler gauges to determine gap between centre electrode and tip.

If too big, GENTLY tap the tip towards the centre electrode until check reveals correct gap as per feeler gauges.

If too small, use a feeler gauge to GENTLY lever the tip away from the centre electrode until check reveals correct gap as per feeler gauges.

4. Re-instal spark plugs

One other possibility (unlikely) - check the plug onto the Crank Angle Sensor (the roundish grey thing on the front of the engine)

[pawson]

no worries.........