A friend has called me wanting help diagnosing a problem he had with his RX-7 today. He was driving to work (driving his car very hard) and all of a sudden it started running really rich. He pulled into the parking lot at work, and some people told him there was fire coming from the bottom of his car. He got out and looked under and his exhaust and Catylitic converter was glowing red hot and there was a hole where an air tube or sensor used to be in the converter. After it had cooled he started it up, and it was still running very very rich. I have never owned a rotary, and know very little about them, any help would be apreciated.

TIA,
JJ

 

Clogged cat would be my guess. Maybe not for it running rich, but for it glwoing and flaming and watnot. I say replace the cat, or gut it depending on your emmisions laws. As for running rich i dont kno.

 

Also, how did he kno it was running rich. What were the symptoms

 

Running rich (or so perceived) because there is no more air injection to sooth the stench. Replace the cat and hook up the air line, all good.

 

Yep, Steve's right - the airpump feed line to the catalytic converter (the 3rd one, under the passenger seat) likely got clogged or stopped pushing air, which resulted in the cat overheating.

There is an 'idiot light' on the dash for "Exhaust System Overheat" that he should have seen. Once the cat is replaced, or the airpump line replaced, he should be fine.

 

Running rich makes the exhaust cooler.

Running lean makes it hotter.

Fuel is just an ignitor oxygen is what is burning.
More oxygen burning the hotter the exhaust temps.

Sounds to me like he is running very lean.

If he is running very rich he should have black smoke from the exhaust.

Did the car loose power?

Mike

 

Could be a lot of things.... Just to through out another idea, maybe one of the injectors are stuck (closed/open)

 

Thank you guys...to answer the ?'s it was smoking badly, and the raw gas in the exhaust was so bad that is making ours eyes water. I don't know if it lost power, I would imagine so, because when he got to work it was idling very rough. I will tell him to replace the airpump feed line and see what happens.


Thanks again,
JJ