ECMlink How do I add fuel to closed loop idle?

[KFred 513]

So I've had a problem with my car not idling during cold idle. I have fixed it by adding a homemade ISC. It's just a 12v switched solenoid that I turn on and it creates a 1/4" hose vacuum leak to give the car more air for cold motor starts.

I have also adjusted my cams to get rid of overlap to help create a smoother idle. Other changes include; adding timing to my maxOctTiming table in link for idle cells, changing OpenLoopMaxOct idle cells to 13.5. My target idle is 1100 and once warm idles great.

My car now starts and idles solid which is an improvement, but when it switches to closed loop it leans out and stalls. All of this trouble may be due to a q45 throttle body, which I will be replacing with a stock 1g TB soon. I'd really like to get this running good for the time being, so if someone can help me richer up closed loop idle I'd appreciate it.

 

[96ETT]

If it works fine in open loop but not closed loop then I would check your O2 sensor. When it goes closed loop that is what it is looking for to make adjustments. Also I hope your target idle is not 1100 just because it doesn't run well below there. That means your tune is bad as well.

 

[gofer]

You're asking about issues with your tune using ECMLink in the Tuning and Engine Management forum and you're describing your issue without attaching a log. Post a log. Our help would be more useful, right now it's our best guess.

If it goes into CL fuel control and goes lean you more than likely have a vacuum leak, when was the last time you did a boost leak test?

 

[KFred 513]

If it works fine in open loop but not closed loop then I would check your O2 sensor. When it goes closed loop that is what it is looking for to make adjustments. Also I hope your target idle is not 1100 just because it doesn't run well below there. That means your tune is bad as well.

In open loop its hitting my targeted 13.5 AFR. When it switches to closed loop it moves to a stoich ratio, and then about 30 seconds later will lean out and stall...all of this is only on a cold motor. Once my temps are up, it idles solid.

I have been changing things around to get the car to idle on a cold motor so yes my target is actually 1150rpm. It doesn't run well below there? Meaning what?

You're asking about issues with your tune using ECMLink in the Tuning and Engine Management forum and you're describing your issue without attaching a log. Post a log. Our help would be more useful, right now it's our best guess.

If it goes into CL fuel control and goes lean you more than likely have a vacuum leak, when was the last time you did a boost leak test?

I know I didn't post a log, I don't have Internet right now so I'm using a 3G ipad until I get it hooked up (just moved). I also posted it here in the tuning/EM sub forum because I didn't have a log to post, and generally the ECM link forum requires one. You can move it if you'd like, especially now that I have one.

As far as the vacuum leak goes, I'm on speed density so a leak shouldn't cause me to go lean. I need to do a BLT and I have everything for a tester, but I no longer have a compressor . Ill do one as soon as I can.

Ill also try to post a log. I was hoping someone had an idea of what could cause this without seeing my setup.

i popped in the library to upload a log i took on the way...unfortunately it isnt a cold startup log but maybe something will stand out that isnt right.

 

[gofer]

As far as the vacuum leak goes, I'm on speed density so a leak shouldn't cause me to go lean. I need to do a BLT and I have everything for a tester, but I no longer have a compressor . Ill do one as soon as I can.

Ill also try to post a log. I was hoping someone had an idea of what could cause this without seeing my setup.

i popped in the library to upload a log i took on the way...unfortunately it isnt a cold startup log but maybe something will stand out that isnt right.

Unfortunately that's a bit of information you should discard, a vacuum leak running SD sure will create a lean condition if it's close to the MAP sensor even if it's on your IM. Odds are it's a decent size vacuum leak near the TB/IM area...

Head to your nearest gas station and bring your BLT, most of their air compressors have a code that turns it on without coins. Just go inside and purchase a water/energy drink/12-pack of Bud (whatever you want) and ask the clerk for the code to turn it on and 9 times out of 10 have no problem giving it to you. This is how I've done BLT's on the road if I'm away from the garage or before I had a air compressor.

Did you install anything since the has started happening?

 

[KFred 513]

Well the large vacuum leak theory is 100% on point, I have created a vacuum leak using a switched solenoid to raise my idle in an effort to keep from "peddling" the car to keep it running on cold starts.

The solenoid was working alright, but it would still idle really low, and sometimes stall. I read on evom that guys are richening up idle and adding timing to make a car with cams idle better. So I tried it. Idle timing cells went from 5* to 12* and 14.5 to 13.5 AFR. I also adjusted my cams. Intake cam got retarded 2* and exhaust advanced 2* to reduce overlap and create a smoother idle, which it did once the car is warmed up.

Both of those changes helped give me a more solid cold idle for ~1 minute. Now it will idle on point in open loop, switch to CL and lean to 14.7-15 and then in about 30seconds will lean out until it stalls. Ill try to get a log of this happening tonight or tomorrow morning and post it tomorrow night.

I could also mention that my car isn't very smooth from a stop. When I hit the gas to start moving it goes lean, then rich, which may be normal behavior but it isn't smooth power off the line.

And that's a good point about the BLT. I bought a quick disconnect air compressor fitting, but maybe ill just put a valve stem in it instead(havent built it yet). The best part is air is free around here at the gas stations...maybe they feel bad for only having 92 and no E-85!

 

[KFred 513]

Well I started looking for possible exhaust leaks tonight. Of course there is a bad leak right at the hotside/o2 housing. I'm going to order that gasket, down pipe gasket, and injector seals. Hopefully this will clear up that stalling problem.

The thing that gets me is the car will now idle for about one minute solid with no throttle....then it dies. It's not an ignition thing because it is slow, feels like it is being starved, and my timing stays in the same DA cell as it stalls. I feel like an ignition stall would be abrupt.

The leak also explains why my wideband dances around more than it should, and why fuel trims do the same with constant throttle cruise ~5%. I guess I'll just have to see if it can be the cause of the stalling, although I am doubtful

If it works fine in open loop but not closed loop then I would check your O2 sensor. When it goes closed loop that is what it is looking for to make adjustments. Also I hope your target idle is not 1100 just because it doesn't run well below there. That means your tune is bad as well.

Sitting here at work I got thinking about this comment, is it not the opposite of what happens?

Open loop targets your maxoct table and adjusts fuel based on Ohh inputs. Closed loop uses airflow and adjust fuel based on history (fuel trims).

 

[96ETT]

Sitting here at work I got thinking about this comment, is it not the opposite of what happens?

Open loop targets your maxoct table and adjusts fuel based on Ohh inputs. Closed loop uses airflow and adjust fuel based on history (fuel trims).

Open loop does not adjust fueling at all, it simply uses tables to lookup fueling based on map and rpm. Closed loop uses the O2 sensor for feedback. Basic engine calibration knowledge.

 

[KFred 513]

Open loop does not adjust fueling at all, it simply uses tables to lookup fueling based on map and rpm. Closed loop uses the O2 sensor for feedback. Basic engine calibration knowledge.

Your right, I don't know why I got thinking that. I agreed with it the first time I read it, and then just got stuff twisted in my head somehow. Would you care to explain the idle comment though? I didn't have this problem until I raised my idle speed. Previously it just stalled no matter what until about 108*. Now it idles decent in open loop (rich) but shortly after it hits closed loop (30-60 seconds) it goes lean. It feels like the ecu is just pulling fuel out for some reason, and if the motor is cold enough to the point of it stalling

 

[ohlegend]

Did you ever solve this issue? I am having a similar issue with my 2g