How do you fix a misfire on a Mazda millenia?

Answer 1

first, get it scanned. see what the codes are. if 0300, that is random miss. specific would be like 0301(cyl #1), 0302(cyl #2), yada, yada. then, figger out which engine you got. 2.5-conventional ign system, distributor, hi tens wires, yada, yada. or 2.3, cop system. then there are several ways to go, depending on which engine. i would start with plugs, then wires, cap, rotor, dist. this is for 2.5. on the 2.3 it is way more difficult. and depends on how bad the miss is. and what you want to spend. since we have 2 2.3's, what i do is get the CORRECT spark plugs, and a full set of coils that i know are good. then i change them all. on the 2.5, it is so easy, you can do it with one hand, blindfolded, behind your back. on a 2.3, it takes 2 men and a small boy, and a lot of patience.

My two cents after 120k miles ownership of a '99 2.5L

- Replace Rotor Cap

- Replace Rotor button <Caution> buy this locally as there are TWO types for the 2.5l and it depends on what year and where on the assebly line the change when into affect. They look the same Except for a subtle difference in the shaft shape.

- Replace Sparks <Caution> Do NOT use Platinum or Split or Multi Point plugs. Use STD NipponDenso copper. The promise of better performance is crap, and actually has adverse affects on performance.

- Replace Entire Wireset - Next to last and almost the most expensive step.

Notes:

Burn 93 Octane ALWAYS on the 2.5l. It especially likes as much Ethanol you can get in the blend. Mine always ran best on the cheaper 93 with 15% Ethanol with never any misfires or sluggishness.

The comment above about the 2.5 is partly accurate - The back 3 are hard to get to using std Tools in your garage. Be carefull on the spark changes here yourself here as it is EASY to cross thread these due to their placement and angle. Place these and start them BY HAND first.

again, BAD answer. first off, factory RECOMMENDED plugs are platinum tipped. they are good for 60k. and 15% ethanol is too much. check with Mazda, they will tell you max of 10%. and, if you have a properly operating knock sensor, you can use any octane, but it is best to use the factory recommended. which is 91 or better on a 2.3. course, if you are stupid, and drive around for 3 years with the cel on, then yah, use the best grade you can get. and if you have trouble getting to the right bank plugs on a 2.5, you need to let the pros do it. but get estimates first, or you will be paying a shop twice what the going rate is for stuff like a knock sensor. sheesh. 800 bucks. i have some land in west Texas for sale