cold start issues - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Javi802 · 12-01-2014, 06:28 PM

I have an sr20 in an s13 and on a cold start, with my consult plugged in to my lap top, i see that once its warmed up (about 150F) the timing likes to stay around 16btdc at idle

And while cruising the afrs are rich. Between 12 and 13

BUT, if i turn the car off and back on... the timing goes back to what it should. At 15btdc with a little fluctuation at idle.

As well as the cruising afrs going back to between 14-15

Does anybody have any idea as to why this happening?

Javi802 · 12-02-2014, 04:14 PM

So i was reading on open and closed loop and I'm wondering if my car stays in open loop for some reason. That is until i shut it off.

My o2 sensor also does some funky things at idle. Ive read that it should be fluctuating at idle.
Mine will fluctuate some, but then stay set on the rich side and stop fluctuating. It'd intermittent though.

I ordered an o2 sensor. Figured it wouldn't hurt to change it out either way.

vipergtsr1000hp · 12-04-2014, 07:39 AM

had a similar problem. it turned to be a bad fpr though.

cotbu · 12-04-2014, 01:09 PM

Op, you need to let the temp reach 80c to be considered warmed up. That's about 176f at that time the 02 signal should fluctuate about 10 in 5sec. Don't quote that.

Now after your warmed up and the 02sig has been caught by the ecu then the afr should be 14.5-15.2 at idle. If you are richer or leaner? You may need a return or do some more diagnosing.

I would also verify that timing, and
re-sync as well.

Sent from my Slightly Tuned Note 4!!!

12-01-2014, 06:28 PM	#1
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 29 Posts: 470 Trader Rating: (10) Feedback Score: 10 reviews	cold start issues I have an sr20 in an s13 and on a cold start, with my consult plugged in to my lap top, i see that once its warmed up (about 150F) the timing likes to stay around 16btdc at idle And while cruising the afrs are rich. Between 12 and 13 BUT, if i turn the car off and back on... the timing goes back to what it should. At 15btdc with a little fluctuation at idle. As well as the cruising afrs going back to between 14-15 Does anybody have any idea as to why this happening? Last edited by Javi802; 12-01-2014 at 09:29 PM..

12-04-2014, 01:09 PM	#4
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 47 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Op, you need to let the temp reach 80c to be considered warmed up. That's about 176f at that time the 02 signal should fluctuate about 10 in 5sec. Don't quote that. Now after your warmed up and the 02sig has been caught by the ecu then the afr should be 14.5-15.2 at idle. If you are richer or leaner? You may need a return or do some more diagnosing. I would also verify that timing, and re-sync as well. Sent from my Slightly Tuned Note 4!!! __________________ LoverTechnologies "Half Broken Things!"

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12-02-2014, 04:14 PM	#2
Javi802 Zilvia Junkie Join Date: Jul 2012 Location: Oklahoma Age: 29 Posts: 470 Trader Rating: (10) Feedback Score: 10 reviews	So i was reading on open and closed loop and I'm wondering if my car stays in open loop for some reason. That is until i shut it off. My o2 sensor also does some funky things at idle. Ive read that it should be fluctuating at idle. Mine will fluctuate some, but then stay set on the rich side and stop fluctuating. It'd intermittent though. I ordered an o2 sensor. Figured it wouldn't hurt to change it out either way.

12-04-2014, 07:39 AM	#3
vipergtsr1000hp Zilvia Junkie Join Date: Apr 2010 Location: dirty south Posts: 307 Trader Rating: (2) Feedback Score: 2 reviews	had a similar problem. it turned to be a bad fpr though.