Can a blown fuse cause rough idle ??
 

Hey wondering after many days of floods here my rx8 developed a rough idle , when adding gas it shakes and vibrates and there is loss of power but it drives. The check engine light is on ...Could a fuse go if so which one?? will also check coils today..I do not have a scanner I repeat and I am in europe so hard to find one. The engine light is on and now it began to flash at times.


regards

engine only has 10,0000 km on it from the dealer.

I have two rx8's this one is my European one as I am in europe right now

Not a fuse. Probably a coil. Don't drive it like this. A scanner can be had at any garage or for $15 on Amazon.

Many days of flooding the engine? Or actual floods?

floods as in rain ..the car sound exactly like this...!!and acts the same way...no idea what the issue was with this guys car but also tried to message him... my car stays alive now at idle but at the beginning was dying too. It all happened after I hit a big puddle of water and all of a sudden it started doing that.



go to 5:50 in the video

Driving through deep water can cause many bad things, but start by checking the coils and the spark plugs. Possible the water popped a wire off one of the leading spark plugs.

hey guys so I checked the coils and all of them looks all black brand new. Only 10,000km on the new engine and spark plugs and coils. One of the coils had a bit of white residue on it . Here is a pic. I do not think this could cause such an engine shake and rough idle ???


regards.

p.s. when I was taking off the negative from the batter I almost got shocked cause the metal tool touched the battery cover which is strange usually the plus would do that ??

Yeah, the white spot doesn't mean anything.

You may want to check the battery with a multimeter. Put the positive end on the positive terminal and put the negative end around the battery and see if you are reading a voltage. It should be close to 0 but if you are reading a noticeable voltage, wipe it clean with some baking soda solution.

is it possible to check the coils while running the car and disconnecting one by one the top wire hoodie to see if it changes idle of the car or produces spark?

Yah, you can disconnect a plug while the engine is running and it should be okay for a short time.

A better method is to disable the fuel pump and crank the engine with a coil tester attached to the plug wire.

Use one of these to test the coil:
http://a.co/eMOBsla

okay tested all the coils and the spark is there in all four. But the engine is still running rough :( so what's next. I also check spark pug boots connected to the spark plugs and all are fitted in well.

Make sure that the correct spark plugs are in the correct holes and that the correct coils are connected to them.

https://www.rx8club.com/series-i-tro...5/

The check engine light is trying to tell you exactly what's next. Have you read the code yet?

the funny thing is after disconnecting the battery all the codes are clear and the check engine is not on anymore :(.

what was interesting is that while the car was running I took off the spark plug boot on each rotor and it did not make a difference ...engine kept on running the same no difference while leading and trailing spark plug boot was being removed ..is that normal ?

That's normal if you have bigger problems than ignition.

Did you make sure that the correct spark plugs are in the correct holes and that the correct coils are connected to each spark plug?

yes all are correct

thinking what else could spraying the engine with water flood or short...other than the ignition coils.

Dude. The codes.
Disconnecting the battery will clear them, but if you run the car again, whatever the problem is will come back. If it doesn't and the car still performs poorly you have bigger problems.

Cold water on a hot engine can crack large metal parts. So there's that..