Hi there, I have an 04 at RX8. When I'm doing about 60 mph and floor the gas it starts to accelerate to about 90 mph then begins to slow down while the gas is still floored and the check engine light begins to flash. If I accelerate gradually the car will go to 116 mph with no problems. I believe when I tramp on the gas it's causing the engine to miss fire thus losing the power because too much gas is entering the chamber and is not being burned off quick enough. I'm no mechanic so I'm just guessing that this is the problem. I would take it to the dealer but that doesn't help me with understanding the problem and the dealer here is brutal they are the worse around, so it's a last resort to take it to them. Any info on what's going on? If it is miss firing would new plugs solve the problem? Thanks

 

How many miles is on your 8? How many miles on the plugs, coils, and wires?

 

Yes you are misfiring, these cars do that under WOT at times. Its no biggy.

If you take it to the dealership there going to tell you they can not duplicate your problem because for one there not going to push your car beyond the posted legal speed limit. To much of a liability risk. So don't even ask them to do it....

I don't know if this may help you or not, but when i went to larger set of spark plug wires i got that flashing check engine much less under WOT. Now it happens only once in a blue moon. It may or may not help you, but like they say always start with the cheapest fix first. Change your spark plugs out too...

 

Im with this guys, If i was in this position i would change Spark Plugs, Spark plug wires, and Coils. also do a Engine Cleaning, just incase :D
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-mazda-zoom-power-engine-cleaner-engine-cleaning-seaform-142852/ here you go!

 

Thanks for the responses. There's 47, 000 miles on it, I purchased it used in December past, so I don't know if the plugs have ever been changed, so it probably be a good idea to replace them. Any ideas on type of plug to use, will just any brand work. I priced them at the dealer and they want over 300 for a set so I'll have to do some shopping around.

 

http://www.fluidmotorsports.com/p-95...ccesories.aspx

Fluid is your best friend, here you go, and a hell lot cheaper then the dealer. also don't forget you need Two Trailing plugs and Two Leading plugs total of 4 plugs

 

Thanks.

 

i was going to say you can get coils here cheaper. but looks like they increased their price from $25 to $30.

wtf. :/