Hi all!
I purchased my 06 automatic rx8 but it has a bad idle and dies at warm up. I did some searching and checked all the vacuum lines but found no issues.
i did get a po411 engine code for incorrect air flow.
After that I did replace three vacuum solenoids at the bottom of the manifold and the vacuum lines with silicone hoses. I also replaced the spark plugs, wires and ignition coils. One trailing ignition coil did have a big stain and I was told that means it’s bad but regardless all were replaced. The car does run better but still get the surge and dies at idle. Once it’s warm and hot it runs good And when I put it in park it does a quick surge and then idles normal, even with the ac on it’s normal. I did a compression test and got 95 94 96 on the front rotor and 92 95 98 on the rear rotor. Has anyone ran into this issue before? Any input would help.
the car is all stock as well

 

Sounds like a vacuum leak (everything on this car could potentially be a vacuum leak ). What are the fuel trims on a warm idle, to the best of your ability?
Have you double checked that the spark plugs are wired to the correct coils? Same question for injector wiring. What is the history of the car? Has the engine been out recently? Getting injector wiring wrong is a common issue when installing an engine.

 

I don’t know the fuel trims but I’ll check once I get home from work. The plug wires and fuel injectors are on as I did check them when I had the manifold off.

 

Was not able to get a fuel reading due to my scan tool not having that ability.
i did manage to use a smoke machine and checked the manifold and also the hoses that run off to the back side of the lower manifold and got no obvious leaks I took the manifold off to inspect everything and nothing stands out. The fuel injectors are wired correctly and plug wires are ran correctly. Before I took the manifold off and had the car running I did notice that one solenoid makes a lot of clicking noise and I don’t know if that’s normal. It’s the solenoid that’s right next to the oil top off cap.

 

Spark plug wires are correct as well

 

That is the evap solenoid and yes can cause issues. It shouldn't be clicking all the time.
Can you scan tool read live data? Ltft and stft are the fuel trim dtc's. You can also check airflow on a warm idle, should be 5.6g/sec at 800 rpm. If it's less, that'll be a clue.

 

I was able to get these readings

 

I’ll put the manifold back together on the car tonight and get some more readings

 

At what RPM was this taken? It's a little short for 800rpm but not terrible, the computer should easily be able to compensate.

 

This was at idle after it was warm

 

I was able to get these fuel trim readings

 

I was able to get these fuel trim fuel trim readings.

 

Your long term fuel trim is almost at the negative limit (-21). Typically this happens when the primary and secondary fuel injector plugs are reversed. Easy mistake when installing an engine, the wires are yellow and beige, and probably very dirty. Make super sure they're correct.

 

Ok I’ll check the colors

 

Both primary were incorrect. Now the fuel trim is way better and the car warms up normal and drives like a dream.
thanks for the help

 

Glad you got this sorted out quickly. I went through a ton of parts and headache before I realized the previous owner did the same thing to my car.

 

I definitely would have never thought about the fuel injector connections being wrong. I was lucky enough that Loki knew exactly what it was.