So I started my M30 E30 Vert up last week for the first time since January. I'll admit it; I probably should have started it up intermittently from January until now, just to exercise it. But since I didn't, here we are.
So I went to take the car for a drive and I get a terrible sputtering when I try to accelerate, as if it has no power. When I let the car sit and idle, it idles terribly low as if it's going to stall. I turn the car off and then turn it back on immediately and it drives well for about 10 seconds until it starts sputtering again. My CEL goes on and I get the infamous 1222 code, which means that anything can be wrong with the car that causes any out-of-spec air/fuel ratio for an extended amount of time (I believe it's 10 seconds). I have an '89 735i engine, so it's motronic 1.3 and the stomp test and codes apply.
I unplug the battery and let the car sit. I've determined the following symptoms: It only happens when the car is warm, not cold. It's intermittent, which insinuates an impending failure of a part. It idles high when warm and sometimes bounces between 1300 and 1500rpm when, for example, I'm stopped at a light. Sometimes, when I'm coasting, the CEL comes on and will go away if I WOT or if I barely tap on the gas. I've seen many other members on here have that problem.
I checked for vacuum leaks, fuel delivery, electrical connections, proper spark, TPS, ICV, AFM, Temp Sensor, all checked as per the bentley manual.
So I'm at the point where i don't know exactly what it could be. I reset the CEL once again and re-started the car. After reading the codes again, I ended up getting exclusively 1221 code, which is O2 sensor. I think to myself, "Can the O2 sensor really cause an erratic, high idle. Can these symptoms be caused by the O2 sensor".
Well yes, it can. A faulty O2 sensor can and will send false signals to the ECU making it difficult to accurately assertain the proper air/fuel ratio to account for. In my case, I replaced the O2 sensor and I haven't gotten the engine code at all. The engine purrs like an M30 should and I'm getting the mileage I expect. It also idles at the prescribed 750rpm
Just a little story for those who get a 1222 code. Don't rule out an O2 sensor. M20 or M30, it's still Motronic.
So I went to take the car for a drive and I get a terrible sputtering when I try to accelerate, as if it has no power. When I let the car sit and idle, it idles terribly low as if it's going to stall. I turn the car off and then turn it back on immediately and it drives well for about 10 seconds until it starts sputtering again. My CEL goes on and I get the infamous 1222 code, which means that anything can be wrong with the car that causes any out-of-spec air/fuel ratio for an extended amount of time (I believe it's 10 seconds). I have an '89 735i engine, so it's motronic 1.3 and the stomp test and codes apply.
I unplug the battery and let the car sit. I've determined the following symptoms: It only happens when the car is warm, not cold. It's intermittent, which insinuates an impending failure of a part. It idles high when warm and sometimes bounces between 1300 and 1500rpm when, for example, I'm stopped at a light. Sometimes, when I'm coasting, the CEL comes on and will go away if I WOT or if I barely tap on the gas. I've seen many other members on here have that problem.
I checked for vacuum leaks, fuel delivery, electrical connections, proper spark, TPS, ICV, AFM, Temp Sensor, all checked as per the bentley manual.
So I'm at the point where i don't know exactly what it could be. I reset the CEL once again and re-started the car. After reading the codes again, I ended up getting exclusively 1221 code, which is O2 sensor. I think to myself, "Can the O2 sensor really cause an erratic, high idle. Can these symptoms be caused by the O2 sensor".
Well yes, it can. A faulty O2 sensor can and will send false signals to the ECU making it difficult to accurately assertain the proper air/fuel ratio to account for. In my case, I replaced the O2 sensor and I haven't gotten the engine code at all. The engine purrs like an M30 should and I'm getting the mileage I expect. It also idles at the prescribed 750rpm
Just a little story for those who get a 1222 code. Don't rule out an O2 sensor. M20 or M30, it's still Motronic.
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