Closed loop engine losing power at idle. Rich condition

Tiny
RB7593
  • MEMBER
  • 1999 ACURA INTEGRA
  • 1.8L
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 140,000 MILES
Ok so I have a stock 99 acura integra. Engine runs solid at a cold start in open loop. However, as soon as it starts to warm up. Rpms go down to the lowest 700 and wants to stall. Once it is in closed loop the STFT will drop to negative 20+, I noticed if I snap the throttle it will zero out but quickly run rich again, if I hold the throttle open to 2500 rpm the STFT will move closer to zero but sort of jump to more negative fuel trim and then jumps back again to closer to zero. And will keep doing this. Sometimes it will briefly hold it but never stays constant. Also at idle I noticed the ignition advance is 15to 20+%, I have no idea where to go from here. Only did fuel filter, sparkplugs. On a side note I checked for vacuum leaks and could not find any and and the map sensor reading will be at 10-12hg on the scanner, if engine is off it will read 28hg, also I dont know if this is relevant but the 02sv11 reading will be at 1.2v sometimes on the scannerl. Im sorry if this is all confusing im just writing everything ive noticed. I have been reading and this could be many things. Where would you go from here, whoever you are thank you for reading this, any help would be greatly appreciated,
-romar
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Saturday, September 12th, 2015 AT 4:05 PM

7 Replies

Tiny
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First thing I would do is pull all the codes, soft and hard. It definitely sounds like an issue in either the O2 sensor circuit, the MAP, the injectors, or the ECM itself. The codes, if any, will give us a good jumping off point as to where to start looking.
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Sunday, September 13th, 2015 AT 7:22 AM
Tiny
RB7593
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I had a p0170 and a p0172 at first, and even though I am still having problems the light wont come on meaning I cant keep pulling codes if its not throwing them, but the problem is persistent
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Sunday, September 13th, 2015 AT 3:19 PM
Tiny
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Untrue. There are 2 types of codes the ECM can throw: Hard codes-those that set the Check Engine Light, and soft codes-those that don't.

Here's what we've got for tracking down the P0172. P0170 doesn't show up in our database.
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Sunday, September 13th, 2015 AT 5:14 PM
Tiny
RB7593
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I appreciate it I have been busy wih work, and thanks for the link, I will look into all that. I know I mentioned my negative fuel trim, but I cranked the car and somehow its slightly going to positive fuel trim now, not the first time I noticed this, also it will jump out of closed loop back to open loop at random for brief moments even if engine is warm. Why do you think it might do this, car has 140,000 miles on it. Thanks again for your feedback mike
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Tuesday, September 15th, 2015 AT 11:39 AM
Tiny
RIVERMIKERAT
  • MEMBER
Something bad in the control circuits. Either a faulty injector control, MAP/MAF, or ECM. Without running through the diagnostic steps, it's anyone's guess.
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Wednesday, September 16th, 2015 AT 8:22 AM
Tiny
RB7593
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Hi is there a way you can resend me that drop box link again
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Wednesday, September 23rd, 2015 AT 10:26 AM
Tiny
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Www. Dropbox. Com/s/uw1g50qmrs0lafz/Integra%20P0172. Pdf?Dl=0
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Wednesday, September 23rd, 2015 AT 2:19 PM

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