ECMlink Need help with idle surge after going to Speed Density

[Built4g63t]

Okay so I'm going to be honest I have no idea how to tune my car on speed density. I just switch over. I bought the plug and play cables right from ECMTuning. I had to pull the intake manifold off to drill and tap hole for vacuum fitting for the map sensor.

I bought the TB elbow with the AIT bung welded on it from STM. I replaced all vacuum lines and hooked up the Ingersol Rand BCS. I'm using the default SD values that is on DSMLink. I have stock 6 bolt motor with the 16g turbo with stock 450cc injectors. The only thing I don't have yet is the wideband o2 sensor now.

Would not having the wideband give me idle surge or could it be something else? I am totally new to DSMLink and speed density so its kinda confusing to me. If anyone has any advice or a place to start looking that would be great.

 

[steve]

Given that the engine is largely stock the first question that comes to mind it why Speed Density. Assuming you have it configured correctly it should run just fine with the default SD settings. So please post a log so we can see what you have done.

 

[Built4g63t]

Well because it was either build my head and have nothing to tune it with or get everything i need so when I build my head and motor I have everything I need to tune it with. I bought the whole speed density kit and bcs all at the same time as I got dsm link so I figured I have it why not use it so I rerouted all my piping and now have my blow of valve going into the atmosphere. And now anything I do to my motor I have dsm link to be able to tune it and be able to go with bigger cams than plug in play ones if I want. So now that I have dsm link now the fun begins with building my motor! I will go out later to get a log to post. Now my question is do you want just normal driving log or what? Also yesterday when I drove the car I wasn't getting the idle surge so its not a all the time issue.

 

[steve]

For seeing how you have configured the ECU a simple startup is fine but if you can get it to misbehave all the better.

Getting ECMLink is a great step, it was making the leap to a less forgiving form of tuning compared to the MAF that I was questioning.

 

[Built4g63t]

Okay So I did 3 different logs, 1 is just a start up another is at like 140 degrees and the other is at wot. But I am having troubles figuring out how to post them. So I've been using this forum site for like 18 years but this is my first time actually posting on it , so please bare with me for now.

 

[steve]

Just like posting a photo except select a log file (*.elg) instead of a jpg or gif.

 

[Built4g63t]

Here is one when it started acting up again yesterday.

 

[steve]

Thank you.
Do you have any O2 sensor installed right now? You're not getting a signal and because the O2 is dead you're also not going into closed loop. It is classic Idle Surge when the RPM's rise with the throttle closed until it trips the coasting fuel cutoff limit and the ECU turns the injectors off. Then the RPMs drop and it turns the injectors back on only to have the cycle repeat.

It's interesting that the AirflowPerRev value is actually being calculated higher at ~900 RPM than at 1400 RPM which causes it to lean out as the RPM's rise. You can also see that the OMNI MAP thinks the manifold vacuum is trending the same way and the timing advance isn't helping.

What does it do if you disconnect the IPS or unclick the enable idle switch operation?

 

[Built4g63t]

That's interesting you say that about the 02 sensor because the check engine light comes on every now and then and DSMLink says its 02 sensor circuit or something. And I have brand new 02 sensor in it. That's why I want to spend the money and replace it with a wideband and just run narrowband simulator in DSMLink.

I will unclick the enable idle switch operation after I get out of work today and see what that does.

 

[Built4g63t]

So when I unclick the enable idle switch operation nothing happened

Should I have the enable normal (factory) settings clicked for the fps and the egr?

 

[steve]

So when I unclick the enable idle switch operation nothing happened

No change or it stops surging?

 

[Built4g63t]

No change or it stops surging?

At the time I unclicked it it wasn't surging and it didn't make any change to the way it was running. I got back from running to town and it was surging when I got home but by the time my computer was done loading up and got connected to the car it stopped surging. So next time I'm going to make sure I take the computer with and have it ready to go.

Do you think I should just suck it up and spend the 200 bucks and get the innovative lc2 wideband and get that hooked up. Do you think it has anything to do with bad AFR?

 

[steve]

I like having a working narrowband sensor in the O2 housing so that I'm not depending on a bit more fragile wideband for closed loop and it gives a reference point for comparing to the WB.

What I was hoping to find out is where the engine finally settles it's idle when it's not receiving the throttle closed signal from the IPS. That might help figure out if the problem is too much air bypassing the throttle butterfly or if there is a tuning issue causing it to idle too fast.

 

[Built4g63t]

What I could do is, I have another throttle body from a spare motor I could put that one on and see if that makes a difference or if it does the same thing. When I had the intake manifold off I cleaned out the throttle body that's on it and put a new gasket on the ISC. I had to put a different one of them on it cuz I had a dead coil in it that fried a driver in the ECU that got repaired when. I sent it in to have DSMLink v3 installed.

I'll also post a log of the car not doing the idle surge and have you look at that one and see if you see anything on it

 

[steve]

When it's not surging and the IPS is working the problem isn't going on. But sure I'll look at it.

 

[Built4g63t]

heres one at wot with no idle surge

 

[Built4g63t]

I like having a working narrowband sensor in the O2 housing so that I'm not depending on a bit more fragile wideband for closed loop and it gives a reference point for comparing to the WB.

What I was hoping to find out is where the engine finally settles it's idle when it's not receiving the throttle closed signal from the IPS. That might help figure out if the problem is too much air bypassing the throttle butterfly or if there is a tuning issue causing it to idle too fast.

So do you have a wideband hooked up at all in your car?

 

[steve]

I have a bung for it in the downpipe but right now nothing is in it since the car isn't being used.

 

[Built4g63t]

No change or it stops surging?

Okay so i just got back from a longer drive and when I got home it was doing the idle surge and I poped the hood and disconnected the idle switch and the idle surge stopped i reconnected it and it began again

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[steve]

Right, and while it was off how fast of an idle did it go to?
The fact that the surging stopped when you removed the cable from the IPS was expected.

Your throttle cable looks pretty tight, there should be some slack (a couple of mm droop) with the throttle closed.

There should be a ground strap (or wire) from where the screw is missing on the top of the TB. Factory there was a metal strap from there to the top front intake manifold bolt. Since your IPS is working it seems that the TB is getting grounded but normally the gaskets keep it from doing so.

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Also look like you're missing the spring clip on the TPS connector that keeps it from getting loose.

 

[Built4g63t]

Right, and while it was off how fast of an idle did it go to?
The fact that the surging stopped when you removed the cable from the IPS was expected.

Your throttle cable looks pretty tight, there should be some slack (a couple of mm droop) with the throttle closed.

There should be a ground strap (or wire) from where the screw is missing on the top of the TB. Factory there was a metal strap from there to the top front intake manifold bolt. Since your IPS is working it seems that the TB is getting grounded but normally the gaskets keep it from doing so.

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Also look like you're missing the spring clip on the TPS connector that keeps it from getting loose.

Okay so put some slack on the cable and about the ground can I run a ground wire to something? So I bought the car from my dad and I've been basically trying to do everything the right way because he never wanted to spend the money on doing stuff the right way. And about the spring im sure its not there cuz the connector has been replace with just a female spade quick connect connector kinda like the one In the picture attached

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[Built4g63t]

I added ground wire and put some slack in throttle cable

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[steve]

Nice work on the ground, assuming the intake manifold ground is running to the firewall you can also just run from the TB to the open screw in front of the cable adjuster.

The spring I was referring to is this one on the TPS. It pretty much the same as what goes on the CAS connector.

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[Built4g63t]

Thanks and yea I ran it to the firewall and the clip is missing on the connector. I need to order one ik STM has it I believe. I had to order all 4 of the ones that go on the injector clips also I should of ordered it at the same time as them but honestly forgot to . They were missing when I bought the car from my dad. I've had to do a lot to the car cuz he never wanted to spend the money to do things the right way.

They do have the retainer clip at STM and I have it ordered!

 

[steve]

So I looked at the last logfile and just idling it doesn't seem to have a problem other than the O2 being dead. Since you say the sensor is new the wiring needs to be checked. I also wonder about the MAP sensor reading -18 inHg at idle. I wonder what a real vacuum gauge would say.

Since with SD all the Airflow measurements are directly tied to the SD VE Table and MAP sensor values I assume your Table is whatever ECMTuning defaults to. Perhaps someone who's done more SD tuning can look and comment.

Any surging since you loosened the throttle cable?