08/13/17 10:18 PM
Ecmlink Idle issues - help please. - UPDATE - SORT OF SOLVED

Hi All,
I'm hoping you can help me out here.
As some of you may know I have been using ECMLink v3 for a few years now and have successfully tuned my car to over 350whp.

But I have an issue I cant seem to resolve/understand.

I changed the valve cover to a new one with -10an breather ports in the PCV and breather locations.
I have dual sealed catch cans one off each and the stock PCV valve is still in play. See photo below.

Prior to this change the can ran fine with no idle or tune issues at all. (The catch cans and PCV were in use at that time but with smaller hoses from the stock valve cover)

Now however I have a choppy idle with heavy surge and very strange log readings for the front O2 and ISC? (See log at this link)
This log is from a warmish engine up to operating temps.

The FIAV is permanently closed.
I have tested the ISC and it is good. I have checked/reset the TPS to .63v, I have set the BISS screw as required but find it very hard to get a steady idle when approaching 30 on the ISC logged value. The idle becomes very erratic and the engine almost stalls.

For all indications it feels like a vacuum/boost leak but I did a boost leak test and it holds 30psi.

Any help would be much appreciated. Feel free to ask any questions.

(poop load of room)
08/14/17 01:30 PM
Re: Ecmlink Idle issues - help please.

I'm working with that same catch can (not installed yet) and it is a huge cheap piece of crap. Doing a boost leak test doesn't include them in the equation because of the PCV valve. Test them separately for leaks, vacuum would be best since that's the condition they operate in but pressure should work too. Also make sure you have a good gasket on your oil cap. I've seen the gasket fall off and it not make a good seal and have the car run idle like poo.

08/14/17 03:19 PM
Re: Ecmlink Idle issues - help please.

Thanks for the input. They are truly cheap Chinese cans. So much so that I used thread sealant on all the fittings and after installing them
In the car I set my compressor to ~10psi and pressurized each can to make sure they had no leaks.

It sure feels like a vacuum leak but I can't find any so am at a loss.
Today I will clean all my grounding points to ensure it is not some sort of electrical earthing issue.

08/14/17 04:21 PM
Re: Ecmlink Idle issues - help please.

Oh forgot to say I had a new oil cap seal about 6 months ago. I removed the oil cap while the car was running and it is sealing very well. (New Dipstick too)

08/14/17 06:14 PM
Re: Ecmlink Idle issues - help please.

I have checked and cleaned all my grounding points to eliminate that as an issue. I re-tested the sealing of the catch cans to 20psi.

The log below is from stone cold until the car stalls as it cant seem to stabilize the idle.


It runs great up until 316 seconds into the log and then you can see the trouble start.
MafRaw hZ and airflow per rev jump up, more fuel is added, the Front O2 start to cycle for longer periods to try and correct the fueling and the fight begins until eventually at the 542 second mark in the log it stalls as hte swings from rich to lean and back become too great to correct in time.

I dont know what is happening at that 316 second mark but I think that is where the answer may lie.

I'm very keen for some thoughts on this no matter how random.

(A hole)
08/14/17 07:08 PM
Re: Ecmlink Idle issues - help please.

You've got IAT and Baro DTCs present. That to me, would indicate an issue with your MAF since these are both integrated into the MAF. The MAF and associated wiring would be my first check.

I need some more information about the car before I can give decent advice on the log. Copy the template and paste your answers in this thread.

Template here: click

Once you complete the template, post a 3-5 minute log with the car idling after getting completely up to temp.

08/14/17 08:18 PM
Re: Ecmlink Idle issues - help please.

Hi Brett,

Yes, I saw those both after posting the log. They will have occurred when I had the MAF unplugged and intake removed and I used ECMlink to help me check and set the TPS with the key on. I cleared them and ran the car from cold to stall again and they did not return so I am pretty sure the MAF is okay.

Template answers below.

1). Any boost, vac, or exhaust leaks?
Boost leak tested 5psi above your max boost with no leaks?
Also tested the seal integrity of the catch cans and associated plumbing to 20psi just to be sure.

2). Verified mechanical timing?

3). Verified base timing?

4). Ignition system
COP or Stock Coil: Stock
Wire brand and Age: Yazaki dated 2001 so 16 years old but have seen no missing or spark issues.
Spark Plug brand, type and Gap: NGK-BPR7ES/.028

If you are having electrical issues, you should follow the troubleshooting method inside the FSM (that you can download off this click and post the resistance reading.

5). Motor health (Compression Test)
Cylinder 1: 150
Cylinder 2: 147
Cylinder 3: 147
Cylinder 4: 150

Leakdown test
Cylinder 1: 6%
Cylinder 2: 6%
Cylinder 3: 6%
Cylinder 4: 6%

All leakage was past the rings.

6). Performed basic throttle body adjustments?
Idle Switch: Yes
Throttle Cable: Yes
TPS: Yes

7). Compression ratio
Stock (7.8:1)

8). Any known bad sensors or brittle wiring?

9). Any DTC/CEL codes?
No (As above)

10). Electrical system
Car off (not running): 12.8 volts
Car running: 14.2 volts

11). Base fuel pressure and injector values
Base Fuel Pressure: 43
Injector Size (cc/min): 1050

12). Properly calibrated and configured wideband sensor
Sensor Brand: Innovate LC2
Calibration Date: Jun2017

13). Type of fuel
Type: 93 Octane
Percent of Ethanol: 10%

14). Watched ECMlink how-to videos?

08/14/17 08:23 PM
Re: Ecmlink Idle issues - help please.

At this point it does not idle when at operating temps unless I back out the BISS so it holds the surging revs higher.
The second log I posted is from cold to the point when the car stalls.
Let me know if you want another idle log as you described and I can back out the BISS and get it for you.

(A hole)
08/14/17 09:02 PM
Re: Ecmlink Idle issues - help please.

Why did you tweak the CoolantTempFuelAdj and FastIdleISCPos DA tables? My guess would be those aren't helping the conditions you're experiencing. Zero them out back to stock, unless you've got a good reason to have modified them. If you don't have any vacuum leaks, then there's no reason the car shouldn't idle with the stock values in place.

Likewise, why did you tweak the WBO2 sim switch point?

If the only thing you changed was the PCV system and the car ran well before, I'd guess you have vacuum/boost leaks somewhere. It's the #1 reason cars still on a MAF run like ass. I'd triple check your boost leak results and ensure you're good to go.

Also, go to the ECU tab and zero out your fuel trims so you can start over.

I'll need and idle log with the car at temp, idling. I can't really do much remotely otherwise.

08/15/17 06:02 AM
Re: Ecmlink Idle issues - help please.

Good questions?!

I do not know why I changed those two DA tables. I have reset them back to the defaults as you suggested.

Is 2.45v not correct for an LC2 wideband?
I have read that 2.43v - 2.45v is correct. If this is not right and I need to change it, just let me know a value and I will.

My wideband is installed downstream of the turbo (about 20-24 inches from the turbo, Not in the stock O2 housing location) and this link click indicates changing the "O2 feedback adjustment rate". Is this worth looking into this given that it worked fine prior to the valve cover change?

I reset the fuel trims and tried another log. It stalled out after a few minutes but after restarting it it idled for a few minutes at full operating temps (The fans cut on and off twice).
Here is the link

Let me know if anything stands out. Tomorrow I will repeat the boost/vacuum leak testing to ensure there are absolutely no leaks.


(poop load of room)
08/16/17 02:59 PM
Re: Ecmlink Idle issues - help please.

Any reason you aren't using the stock narrowband still for closed loop fuel control?

It still sounds like a vacuum leak and reading it again it's VC or catch can related. Did you use a new gasket and half moon? Are all the spark plug gaskets in place?

It looks like you swapped already but I like this thing.

web page

08/16/17 04:25 PM
Re: Ecmlink Idle issues - help please.

A couple of reasons:
I changed the o2 housing from stock to evo3 and broke the stock O2 sensor when removing it. I put the Wideband in the stock location as I was using the stock downpipe and it had no bunghole for a wideband. I had plans to replace the downpipe with 3" eventually so...
I had a 3" downpipe made and when I took it to get dyno tuned a few months back they recommended putting the sensor further away from the turbo as they had seen inaccurate readings from sensors that close to the turbo due to overheating. I had a bunghole installed into the downpipe and moved the wideband. I put a bung in the stock location. I have another stock O2 sensor in a housing, but it has proven very hard to remove so it has stayed there.

It certainly feels like a vacuum leak.
I am going to re-plumb the valve cover without the catch cans today and see if it makes a difference. At least I will know if it is the cans or something else. It looks like it will be a process of elimination from here.

I re-used the existing gaskets as they were only a couple of years old and had only seen about 1000 miles. (This car only gets driven on the weekends these days) They are all in place and appear to be sealing correctly, although I am going to smoke test the valve cover to see if there are any leaks.

Yes, I did use the aluminium evo half moon when I fitted the valve cover last time.

08/16/17 06:01 PM
Re: Ecmlink Idle issues - help please.

Process of elimination
I had some spare hose so I re-plumbed the valve cover without the catch cans. Direct from the valve cover to intake pipe, and valve cover to Intake manifold with PCV in place. (See photo below)

This made no difference to the idle which seems right to me as I had checked the sealing of the catch cans prior to start up and they held pressure without any leaks.

As per the Innovate instruction my wideband sensor is about 20-24 inches form the O2 housing. And the ECMlink wiki I linked above suggests that the O2 Feedback Adjustment Rate may need to be changed to prevent the ECU from "overshooting" and creating a rich/lean oscilation in the tune.
I altered the settings from the stock numbers of 3 for idle and 7 for other to 10 idle and 16 other.
This seemed to actually make the idle worse and the car really struggled not to stall and actually stalled several times at idle, so I changed them back to stock.

I clamped the hose to the intake manifold and pressurized the valve cover from the other -10an fitting, (about 10psi) I used soapy water around the entire valve cover gasket, spark plug gaskets and oil cap and there were no bubbles. So it is sealing to the head perfectly.

This leaves me thinking that it is either an issue with the ECU, MAF, ISC or TPS. Or at least some sort of electrical sensor or signal to the ECU. Let me know if this sounds right or wrong.
I have tested resistance to the ISC coils and they all check out okay.
The TPS sweeps cleanly from 0.63 to 5.00v and it looks stable in the logs.
The MAF was working fine prior to the valve cover change, I removed it with the coupler and air filter attached and sat it on the bench until re-install. So it would be strange for it to fail, but nothing is impossible. The DTC's discussed above in an earlier log have not returned so I'm pretty sure it is okay and they were only present because I turned on the ignition with teh MAF unplugged at one point.

The ECU??? Could the ISC drivers have been damaged during the process of adjusting the BISS to try and stabilize the idle??

I am running out of ideas...

(Turn Right Racing)
08/17/17 07:12 AM
Re: Ecmlink Idle issues - help please.

If I am seeing this correctly, is the PCV valve moved into the rearmost hose? Stock screw-in valve? Do you have it going the correct direction and if it is the stock type, could it be leaking where the hose is attached to the threaded portion?

(A hole)
08/17/17 08:22 AM
Re: Ecmlink Idle issues - help please.

Boost leaks?

How are you testing for boost/vacuum leaks? What specifically is the procedure you're using, and what pressure are you testing up to?

08/18/17 07:51 PM
Re: Ecmlink Idle issues - help please.

Yes it is in the rear most line going to the intake manifold.
Stock PCV valve and correctly oriented.
No leaks, I clamped the hose between the pcv valve and intake manifold when I pressurized the catch can to test for leaks and there were no leaks at the pcv connections. I used soapy water to all possible leak points including the can gaskets and sight glass/oil level interfaces.

Thanks for the questions/suggestions.

08/18/17 07:57 PM
Re: Ecmlink Idle issues - help please.

Hi Brett,
I'm assuming you couldnt see anything glaringly wrong with the idle log I posted? (aside form the surging idle)

oost leak procedure is this click

I built my own tester with gauge which fits to the turbo compressor inlet.
I clamp the hose from valve cover to intake pipe and also the Manual boost controller.

Gauge pressure on the tester is 30psi and soapy water is used to all possible leak points as in the video. It holds the pressure very well and leaks down slowly.

08/26/17 06:43 PM
Re: Ecmlink Idle issues - help please.

I swapped the valve cover back to my original and the issue has gone away?!

I'm going to assume that the valve cover has a leak of some kind.
It is an Evo valve cover and has some difference to our VR4 covers.
The Evo valve cover bolt holes are larger to accommodate M8 bolts instead of the VR4 which uses M6 bolts. The gasket part numbers are different as a result.

None of these differences seem to be the cause as I pressurized the valve cover/Crankcase after installation and sprayed it down with soapy water to try and find any valve cover related leaks and found none.
Also many vr4 owners have fitted early evo valve covers without issue.

Whilst the mystery is now solved, it now means that I will likely get my valve cover drilled out for larger fittings and go from there.

(Eager Beaver)
08/27/17 09:23 AM
Re: Ecmlink Idle issues - help please.

Can I assume that a new valve cover gasket and freshly installed half moons are now in place? Always, always best to replace those gaskets when opening things up.

08/27/17 03:31 PM
Re: Ecmlink Idle issues - help please.

No, I re-used the existing gasket set and the half moon was never removed. As I said earlier they weren't that old as I had rebuilt the head a few thousands miles ago.

09/18/17 04:42 AM
Re: Ecmlink Idle issues - help please.

UPDATE - Based on my assumption that the valve cover was the issue i had -10 an fittings welded to my known good valve cover.
I fitted it and the results are better but not good.

BETTER in that the car does not surge as badly and it does not stall.
NOT GOOD in that the idle is still surging and log values are out of spec.

Here is the current situation illustrated by photos.

When I attach the valve cover breather to the turbo inlet pipe (brass Fitting in the photos) the car idles rough and the STFT, ISC and Airflow/rev values all go out of spec. (See Below)

If I disconnect the valve cover to intake pipe hose and leave it disconnected the car idles great and all the log values come back into line??????????
This is essentially opening 2 unmetered sources for air. One directly after the MAF in the intake pipe and one at the valve cover breather?!?!
This seems to me to be the opposite of what you would expect. (See Below)

Just to re-iterate
With the system closed and the Valve Cover breather line connected to the inlet = rough surgy idle and bad log values
Valve cover breather open to atmosphere and inlet pipe connection open to atmosphere = good idle and log values.
I don't get it?

Any ideas?

10/10/17 02:25 AM
Re: Ecmlink Idle issues - help please.

Well, after too many hours trying to get it to idle accurately (With catch cans, without catch cans, 5/8 ID hoses, 1/4 ID hoses, partial crimping of various hoses in the circuit) I gave up.

I have left the breather line which was connected to the turbo inlet pipe after the MAF disconnected and plugged the nipple into the inlet pipe.

The car idles and runs like a champ, and all tune variable have stabilized and are within "Spec"

This does leave an vacuum leak or open line to the valve cover breather port (Via catch can). But this has caused no drive-ability issues and I will add an air filter to stop the engine sucking in unwanted debris when in vacuum.

The only downside to this arrangement is that I am unable to utilize the vacuum created between the air-filter and turbo inlet to suck crankcase pressure out of the valve cover when under boost.

However the reason for doing this was blue smoke under boost which I suspected was oil not draining from the turbo due to crankcase pressure. With the current setup the smoke is gone. Job Done.

While the catch cans are cheap and nasty they were not the issue.

I am still baffled as to the reason for the poor idle, but am happy with the current outcome as I can drive the car again.

(fighting them with a large needle)
10/10/17 09:39 PM
Re: Ecmlink Idle issues - help please.

Such a strange issue. Have you tried posting this on the ECMlink forums? Might get a more technical response from someone with a similar experience over there.

10/11/17 03:55 AM
Re: Ecmlink Idle issues - help please.

Yes I did. Dave Mertz was very helpful but in the end unable to resolve it?
He suggested it may be some sort of resonance related to the volume of the catch-cans and lines, but it did not change with or without the catch-cans in the circuit.
I even tried different hose sizes and partial clamping of the hoses to upset the flow, but no result.

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