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Old 04-13-2007, 05:42 AM   #1
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Default Weird symptoms

I started up the car today and the car was idling at about 11.5-11.8. When I rev it, the bov relieves and the car goes richer. Then, sometimes the car will start to go back to stoich. I checked for vacuum leaks and intake leaks, and nothing. I started to think of the symptoms of a bad O2 sensor, so I changed it out, but still the same results. I am going to check the spark plug wires resistance tommorrow, but I am getting stumped. Any ideas?
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Old 04-13-2007, 09:23 AM   #2
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what injectors? and was it cold out?
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Old 04-13-2007, 09:34 AM   #3
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yeah plug wires what is the FP? Could be sticking fual regulator. he is running 300's i believe scot and he has a emb.
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Old 04-13-2007, 10:09 AM   #4
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well, even with EMB, it should still be affected by cold starts, so if it's less than 60° or so out, you'll probably notice a 11:1-12:1 AFR at idle before the car warms up. IF it never goes back to a 14.7:1 idle, then suspect the AFM brush and o2 sensor.

BOV: if it's not recirc. then that's normal. Since you meter air, then dump it out, the ECU has less air than it thought it did, so you see rich on the wideband.


*edit* ahhh deja vu!
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Old 04-13-2007, 10:11 AM   #5
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He is also in Hawai. dunno if that matters steve how cold is it over there? was the car all the way warmed up? More info needed ****.
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Old 04-13-2007, 10:18 AM   #6
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Beside the AFM, the same problem can be caused by the temperature sensor on the back of the engine that tells the ECU the engine temperature(green connector) or the wiring going to it.
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Old 04-13-2007, 01:46 PM   #7
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I am currently running just the 1.8 injectors until I get to change the clutch. The coldest it was here is 70 degrees. This was after it was already warm, forgot to mention that. I am going to check the sensor. I just have to get back there. I am also going to go get a gage and check the fuel pressure. The thing that is really pissing me off is that the computer isn't throwing any codes. Usually if it was a sensor, it would show. I think that the injector duration is a little longer now, so that is why I am leading a little more to the sensor and not really the pressure.
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Old 04-13-2007, 07:01 PM   #8
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OK, here is what I have found. Sometimes at idle, it will do this. I took it for a drive and the car responded good. Perfect stoich and when I entered boost, then it goes rich. Came back and now it idles perfectly stoich from 14.6-15.5. I think that maybe the windshield washer fluid has gunked up one of the idle control devices, and it cannot respond very well to any transients. But after driving it around, it warms up the gunk enough to where the component can move freely. It definately has something to do with the idle systems. I let it run for about 15 minutes at idle, so it was completely warm, and it was still doing this. Does that sound like a good hypothesis to you guys? That is the only way that I can explain it, because the temp is not affecting it, no vacuum leaks.
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Old 04-15-2007, 05:01 PM   #9
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Sprayed some carb cleaner into the ISC hose while the car was running, fixed the problem. The windshield washer fluid gunked it pretty bad. I need to go the richard route and try to locate a 55 gallon drum of methanol, and mix my own mixture.
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