About to give up and just let this thing run open loop forever.....
08-08-2011, 12:41 PM
#1
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About to give up and just let this thing run open loop forever..... This is probably going to be my last thread on this stupid issue. If I can't get it solved I am really thinking about keeping it in open loop forever. I don't know what else to do. Thanks for everyones help in the past and for any upcoming help on this issue.
Again this is a newly rebuilt engine. That I have yet to work right. Car runs great when I am in open loop or when I have the O2 sensors disconnected. As soon as it goes into closed loop I can't accelerate worth crap. Even though I have no codes showing these certain sensors bad I went ahead and replaced numerous ones.
Replaced
1. Both O2 sensors
2. Maf sensor and Pigtail
3. ECT-Engine Coolant Temperature sensor in water pump
Maybe I have an exhaust leak, but wouldn't I show a code for a lean condition in one of the banks???
Maybe I have a vacuum leak. I checked vacuum and it is at 11-12 or so. But I also have a fairly big cam.
Any thoughts? Thanks.
Again this is a newly rebuilt engine. That I have yet to work right. Car runs great when I am in open loop or when I have the O2 sensors disconnected. As soon as it goes into closed loop I can't accelerate worth crap. Even though I have no codes showing these certain sensors bad I went ahead and replaced numerous ones.
Replaced
1. Both O2 sensors
2. Maf sensor and Pigtail
3. ECT-Engine Coolant Temperature sensor in water pump
Maybe I have an exhaust leak, but wouldn't I show a code for a lean condition in one of the banks???
Maybe I have a vacuum leak. I checked vacuum and it is at 11-12 or so. But I also have a fairly big cam.
Any thoughts? Thanks.
08-08-2011, 12:57 PM
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I honestly wouldn't mind running open loop forever. This car sees no more than 500 to 1000 miles a year so I am not looking at fuel economy at all. Plus I have a air/fuel wideband gauge to monitor when I spray the nitrous. But I thought that open loop self-adjusts somewhat depending on what closed loop is seeing. Isn't that what we want for performance. Or am I waaaay off in what I just said? haha.
08-08-2011, 01:06 PM
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Yes it stays in open loop and runs flawlessly. I bought new O2 sensors even though I had no codes and it still runs like crap in closed loop. If I can't get this fixed is there anything wrong with running open loop if I'm not looking at fuel economy. Can open loop adjust to all different weather changes?
08-08-2011, 01:09 PM
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He already said he unplugs the o2 and it runs fine. Have you data logged or drove the car with a tech2 in the car to see what's going on? Maybe the MAF IS READING WRONG?
08-08-2011, 01:12 PM
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Sorry.. just skimming posts and didn't see they had been unplugged. Have you checked both O2 harnesses thoroughly to make sure they are not damaged? And, as stated you need to scan the PCM while its running to see what kind of value output the sensors are producing.
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08-08-2011, 01:20 PM
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The O2 sensors are brand new. I have an aeroforce gauge that scans the pcm and it shows both O2 sensors going back and forth from around 50 or so all the way to 900 or so.
08-08-2011, 01:29 PM
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What brand O2s? I just two new Bosch O2s and I am having a sort-of similar problem. In my case it is a misfire. I've been advised to stay away from Bosch so I may be changing them out for AC Delcos.
08-08-2011, 01:31 PM
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From what I remember it is fairly quick. But I thought I read somewheres that I need to read it by keeping it reved to 2000rpms or so to keep a solid stream and not just at idle. Are you trying to see if I'm leaning out? If so I can check with my wideband. I need to get a new O2 for it though. Even if it was leaning out, wouldn't it act the same in open loop.
08-08-2011, 01:44 PM
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Open loop= engine warming and running on preset start up parameters, not reading o2's until at proper temp. Closed loop= exactly the opposite ... Reading and adjusting within it's parameters ..
08-08-2011, 01:45 PM
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my kept throwing codes with them in closed loops and i kept replacing them so i finally had alvin put it in closed loop and never given me any trouble ever since, I honestly still get the same gas mileage so i dont see no point in not doing it
08-08-2011, 01:46 PM
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Yes I first tried to convert it to OBD1 and had Moe Bailey mail order tune it. But came up with this problem so I went back to OBD2 and had PCMFORLESS mail order tune it. Still have the same issue. Moe Bailey will be doing my dynotune if I can ever figure this problem out.
08-08-2011, 01:51 PM
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From what I remember it is fairly quick. But I thought I read somewheres that I need to read it by keeping it reved to 2000rpms or so to keep a solid stream and not just at idle. Are you trying to see if I'm leaning out? If so I can check with my wideband. I need to get a new O2 for it though. Even if it was leaning out, wouldn't it act the same in open loop.
08-08-2011, 07:48 PM
#19
i had this issue also. i got the ve tables close, with that one program that helps (ve master or something like that) and a wideband. after i had a base line in the ve tables and afr was close at idle, great riding around and dead on at wot (i live in a rural area so i can get lots of wot runs without cops). i set the temps so it would stay in open loop SD. now that i had to rebuild, i will have to go back thru the ve tables yet again, oh joy.
