Yet another idle thread

[ShaggyTE]

Ok, I'm needing some help here because I can't figure it out. Let me say that before I touched anything, the car was idling fine /ubbthreads/images/graemlins/applause.gif

Last winter/spring I replaced the radiator, and I also moved the intercooler so it wasn't pushing on the bottom of my USDM bumper. In the process, I removed all of the intercooler piping, replaced the couplers with new ones from SiliconeIntakes, and put a HKS TB elbow on. After that, I did a boost leak test and I was getting leaks at the injector orings. The car has ECMLink and their SD setup that was installed by the previous owner and the MAP sensor was always just T'd into the brake booster line, which I didn't care for. I decided to remove the intake manifold and tap a new port on it for it. When I re-installed I used a new OEM gasket. Put in new injector o-rings, did the tb shaft seals. Did a boost leak test again and I didn't find any. Started the car, as its warming up, it idles fine, the second I touch the throttle it goes to crap.

A few days later I was driving the car and at this time, I got a check engine light for the coolant temp sensor. Drove it home and after I shut it off, it wouldn't start again. Check the wiring, and it had been soldered in several spots and had come loose apart. All the wiring was cracked and in bad shape at the thermostat housing and the O2 sensor (on the car side). I went to the junkyard, found some in good condition and replaced it. Started the car and now the coolant seems to be reading fine in link, but the idle surge is still the same.

Ohmed out the ISC and it checks out fine. I'm frustrated at this point, so I decided to remove the throttle body and make sure I didn't goof anything up. It still super clean, opens and shuts, nothing seems odd. I have it off so I decided to bottom out the FIAV, tapped and plugged the coolant lines on that, and installed a new ISC. Started the car, and its still the same.

So, not seeing any boost leaks, TB, FIAV & ISC should be okay, coolant and o2 sensor wiring should be good. I've attached 3 logs, one with the car starting this morning, quick one on the highway, and one in the parking lot at work. Things that I notice are off; I can't get my intake temperature to read correctly (it's not that cold here yet), my airflow per rev is high, and when I was idling in the lot, the front O2 doesn't seem to cycle correctly and it switches between closed loop and open loop.

I have to note, that at idle, the BOV is open and air is coming out. I would much rather it be closed, but it's on SD and I didn't change anything with the BOV so I'm assuming it was doing this before. It also seems to stay closed at initial startup until I touch the throttle.

Startup

Highway

Idle after Hwy

 

[KiNgMaRtY]

It appears that you have already worked through the common culprits.
Your bov does not seem to be at issue, sounds like its operating normally by the description.

 

[FlyingEagle]

Quoting ShaggyTE:
Ok, I'm needing some help here because I can't figure it out. Let me say that before I touched anything, the car was idling fine /ubbthreads/images/graemlins/applause.gif

Last winter/spring I replaced the radiator, and I also moved the intercooler so it wasn't pushing on the bottom of my USDM bumper. In the process, I removed all of the intercooler piping, replaced the couplers with new ones from SiliconeIntakes, and put a HKS TB elbow on. After that, I did a boost leak test and I was getting leaks at the injector orings. The car has ECMLink and their SD setup that was installed by the previous owner and the MAP sensor was always just T'd into the brake booster line, which I didn't care for. I decided to remove the intake manifold and tap a new port on it for it. When I re-installed I used a new OEM gasket. Put in new injector o-rings, did the tb shaft seals. Did a boost leak test again and I didn't find any. Started the car, as its warming up, it idles fine, the second I touch the throttle it goes to crap.

A few days later I was driving the car and at this time, I got a check engine light for the coolant temp sensor. Drove it home and after I shut it off, it wouldn't start again. Check the wiring, and it had been soldered in several spots and had come loose apart. All the wiring was cracked and in bad shape at the thermostat housing and the O2 sensor (on the car side). I went to the junkyard, found some in good condition and replaced it. Started the car and now the coolant seems to be reading fine in link, but the idle surge is still the same.

Ohmed out the ISC and it checks out fine. I'm frustrated at this point, so I decided to remove the throttle body and make sure I didn't goof anything up. It still super clean, opens and shuts, nothing seems odd. I have it off so I decided to bottom out the FIAV, tapped and plugged the coolant lines on that, and installed a new ISC. Started the car, and its still the same.

So, not seeing any boost leaks, TB, FIAV & ISC should be okay, coolant and o2 sensor wiring should be good. I've attached 3 logs, one with the car starting this morning, quick one on the highway, and one in the parking lot at work. Things that I notice are off; I can't get my intake temperature to read correctly (it's not that cold here yet), my airflow per rev is high, and when I was idling in the lot, the front O2 doesn't seem to cycle correctly and it switches between closed loop and open loop.

I have to note, that at idle, the BOV is open and air is coming out. I would much rather it be closed, but it's on SD and I didn't change anything with the BOV so I'm assuming it was doing this before. It also seems to stay closed at initial startup until I touch the throttle.

Startup

Highway

Idle after Hwy



I found some good videos by Scott Laird posted on youtube, and the ECMlink guys have vids on their site, that show dialing in the airflow per rev (essentially the lowest two boxes or airflow in HZ, then dial in the deadtime on the injectors (affects idle only)). My airflow per rev was at 0.34 and it needed to be lower near the 0.25 range correct? ECMLink says they expect to see 0.25 for a 2.0l engine, they didn't mention anything about cams. I have HKS 264/272 cams installed in my 1G 4g63t motor. 7.8:1 compression ratio. Car idled like it was under less load, but still a wonky idle due to other circumstances (not vaccum leaks but related to starts where the heater timing is still cycling and Link isn't getting a valid 02 swing from the wideband until fully warmed up! Downside to running narrowband sim and input from the Innovate MTX L WB setup - I may repin to incorporate my narrowband back into the mix again - another side story as I sorted things out). This is all assuming no leaks of any kind. I'm running MAF so maybe the above info doesn't completely relate to tuning your speed density setup. Useful info for those that are however.

Do you see the idle stop switch input cycling or are you using a simulate function and it is working just fine?

ISC count sits where?

If your 02 sensor fails to cross the 0.5V threshold for 20 seconds, it will lock it out of closed loop mode. That is a big issue right there like I have having. My narrow band was pegged at 0.2V and never cycled up; hours of idle time and tuning/tweaking just killed it I suppose, never got to drive it more than a block or two. Tried multiple ECU's and even played with the wiring but it all checked out and the WB once wired into the ECU via the yellow wire, was operating just fine and swings between 0.2V and 0.8V (with no real distinction in between which is odd but maybe expected from the translation algorigthm). It works regardless. If the car doesn't get into closed loop mode, and is just like mine was, it won't track and aim for your AFR as you set it. Such was my experience in the last couple of weeks.

 

[ShaggyTE]

So turns out, I believe that it has to do with my TPS. I need to look into that more. I'll post once I have a chance to check it out. I do have an idle switch, but link was set to base that off of the TPS. I'm going to turn it on, and log it to see if it is functioning properly. I think it has to do with the TPS because I can blip the throttle at a stop and then it will calm back down and idle normally.

The airflow per rev used to be around .24 or .25, but now its higher. I didn't know if there was something more I should be looking into for why that would change, or if that would be a result of my temperature sensor being off? Just curious what others thought. I don't think that would cause my surge.

ISC, I'll have to double check. Is that only controlled by adjusting the BISS screw? I know its supposed to be around 30, right?

O2 I'll have to look into more as well. Mine could just be old too.

Thanks for responding!