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Flashing cel

pcb

The Diagram Dude
:
2002 MP5
I rememeber PM'ing a forum member from Oklahoma who did a tune up including replacing coils, then his car would mis-fire but only after a complete heat soak.
He even brought an oscilloscope home from work trying to find the problem.

He finally decided to put his old coils back on and that fixed the problem.

You'd think that putting some brand new parts on your car would make it run better and not make it fail

I have my old original coils in my trunk in case I need to replace them on the side of the road.

I replaced my coils shortly after joining this site and learning about all the weird and strange problems coils were causing.

I didn't know about the Hitachi coils at the time so went with Beck Arnley.

They've been fine for more than five years but I'm sure if I modded my car, they would fail.
 
:
Mazda P5
Well it ran for 5 months before then it had cylinder three misfire. Then put new one on. 10 minutes later cylinder three misfire. So it can't just be crap on cylinder three.
 

pcb

The Diagram Dude
:
2002 MP5
Well you're in the middle of injectors now so you'll see what that does.

But I'm still betting you've got crap on coils #1 & #2. lol
 

pcb

The Diagram Dude
:
2002 MP5
I could see a bad/corroded connection causing a drop in KV but the coils usually spark from the coil to the valve cover instead of though the spark plug wire to the sparkplug.

This is a COP coil from my parts car.



Once it starts to rust and turn to shit, it can spark through the rust and crap when there's less resistance to the valve cover.
 

pcb

The Diagram Dude
:
2002 MP5
Higher quality coils can produce a stronger spark and the insulation around the coil is of better quality so you don't throw the spark to the valve cover or short out internally.
 
:
Mazda P5
Well do you think running different spark plugs have anything to do with it? Since I only changed out the coils could having different plugs play a role?
 

pcb

The Diagram Dude
:
2002 MP5
I think that's quite possible but the coils should be able to deal with it regardless.
 

pcb

The Diagram Dude
:
2002 MP5
It looks like you're using the plugs for the 1.6 L engine.



It would probably be smart to put in a plug recommended for the 1.8 or 2 L engine regardless.

But you were using those plugs for 5 months with no problems right ?
 
:
Mazda P5
Correct because I read that those were the plugs for the fsze. It was making good power of it still throws the code I'll have it checked for compression.
 

pcb

The Diagram Dude
:
2002 MP5
Well you have to wait until your new injector is installed anyway, so see what results you get with that.

All I'm really trying to say is that if you end up having to get new coils again, go with OEM.
 

pcb

The Diagram Dude
:
2002 MP5
If you have a fouled cylinder you can get carbon build up in your combustion chamber.

This is a piston from my parts car that was burning a lot of oil.





If there's a lot of built up crap in the combustion chamber you reduce the volume and increase the pressure then you need more KV to pop a spark through a spark plug.

PS.. That spark plug looks fine.
 

pcb

The Diagram Dude
:
2002 MP5
If the center of the picture is the top of your piston then it looks fouled.

 

pcb

The Diagram Dude
:
2002 MP5
These are my piston rings...




Notice how there's no expansion of the oil ring.

Our engines have great compression but the oil rings get siezed and let a butt load of oil past them.
 
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