someoldhobo

I have a 2004 with 127k that has a re-man engine that only has 10K on it and I have been having a backfire problem. If I put my foot into it my 2nd rotor registers a backfire above 6500. I have tried swapping my 1st and 2nd rotors coils/spark plugs and the problem is still in the second rotor. The coils have less that 25 k on them and my plugs and wires have 10k. When the CEL flashes I do not notice any difference in power, but I back off until it goes away. I have reset the ESPS and it still backfires above 6500 when i put my foot in it. I can sustain 6500+ if I do it gently but it does not like it when i do it quickly. Secondary fuel injector on rotor 2? Other ideas?

9krpmrx8

iTrader: (46)

Hmmmm, have you checked to see if your cat is glowing red after driving for a while?

someoldhobo

No, but my CAT went out before my last engine did. I got a new one and i know that smell. On a side note, F CARB, the only one that's legal in California is the Mazda one... Lame

9krpmrx8

iTrader: (46)

I know your coils are not that old but I had stock coils fail after 15,000 miles so I suggest testing them.

Use the FSM or this

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-testing-all-rx-8-coils-gm-ls2-yukon-coils-sparkplug-wires-222641/

someoldhobo

I have been trying to justify upgrading my coils but if the oem coils were the issue the problem would have moved when i swapped the coils between the rotors.

9krpmrx8

iTrader: (46)

Did you swap wires?

someoldhobo

I don't think they will fit if i switch them. I bought a 8.5mm Magnecor set and at first i had no issues, but i did start to have problems. Before that i a had a MDS make your own for a 4 banger but that was not water tight. Do you think should try the MDS on rotor 2? As long as it does not rain... lol.

9krpmrx8

iTrader: (46)

Where in cali are you? The cali guys are pretty cool, I am sure someone has an extra set of factory wires laying around. I had a couple of sets but I think I have given them all away already.

someoldhobo

If it the wires i still don't understand why it would be a consistent problem. I would think it would be more random?

9krpmrx8

iTrader: (46)

Hard to say man, but without eliminating the plugs, coils, wires it's hard to move on diagnosing the problem. I had a misfire issue just like this but it ended up being a bad coolant seal and I had to replace the motor. But with me I was able to eliminate ever other possible cause leading me to that conclusion.

someoldhobo

Sounds like i should try my old wires and maybe buy a compression tester... The backfire could be because of the secondary fuel injector on the second rotor, right?I figure its a fuel/air problem... hopefully.

9krpmrx8

iTrader: (46)

Well rotary engine compression testers are expensive. You can use a regular compression tester if you remove the check valve but it's still not easy. Fuel injector problems are rare, I doubt it's that.

outhid

I had the same problem right now, engine light stays on and start flashing after 5000 rpm, I had engine code saying second cylinder is misfire. Tomorrow I'm going to put 4 new coils and see if the engine light and misfire would go away. Also at the same time I had my engine flooded this morning too so two problem at the same time. Hope the new coil solve every problem. I got new NGK wires and plugs brand new waiting for the new coils too so they all ready to go on the engine tomorrow.

someoldhobo

I tried a normal compression tester on the last motor and it didn't give me any useful information, plus this engine does only have 10k so I really hope its OK. It just seams odd the issue is repeatable and consistent. I think ill try my old wires later today.

someoldhobo

So I tried my old wires and I still have the same problem. The coils, plugs, wires all seam to be ok. Anyone got any ideas?

someoldhobo

Well i guess its time to do what the FSM says to do. I just need to get my OBD-2 from my buddy and ill start with the freeze frame data and move from there.

200.mph

iTrader: (9)

make sure you didnt crack the porclin on one of the plugs. i did this once and it was easy to figure out wich one.

hood open preferably shady or dark under hood, car running have someone give it some gas. i could see/hear the arc to the "block". do not touch it.

dont know if this helps but worth a shot

someoldhobo

I don't think it is the plugs because when i swapped my coils from rotor 1 to rotor 2 i swapped the plugs also. The problem didn't change to the first rotor. The really funny thing about this is when i am stationary it revs all the way to fuel cut off just fine. It only when i am moving and whomping on it that i have the issue.

200.mph

iTrader: (9)

clean maf, ess, and air filter.idk

9krpmrx8

iTrader: (46)

Of course you are not under load or using all the injectors. You will chase this problem until you properly diagnose it.

someoldhobo

I will be getting my OBD-2 back tomorrow, i continue the troubleshooting then. I plan on following the FSM line by line... I was just hoping someone that had a similar issue and had some insight.

outhid

So I got my started. With new ngk spark plugs but the cel still on flashing for code p0320 or p0302 don't remember the code number but call for misfired cylinder 2. I think I need to replace cat and injectors or clean them up.