ECMlink Help with idle issue

tschuhly · May 2, 2026

I am really struggling to figure out what is going on with my car. Instead of explaining, I will post a video link as well as my log that was recorded during the video. It should be noted that I do not touch the throttle at all in the video though in the log I do.

I will say that this is the first time the car has been ran since I have owned it and basically put it completely back together. I have checked everything that I can think to check including compression is 150, TPS is set to 0.63v, Boost leaks/smoke test is minimal, fuel pressure is set to 43ish, oil pressure is reading about 40psi cold (i think), etc.

I had a couple of my mechanic friends look at it and they think that it needs a better base tune before I go for my actual official tune. It is also important to note that although I am confident in my abilities to figure things out, please assume I don't know something if you have a suggestion because you are probably correct LOL

. I do have a wideband that I tried to setup in ECMLink though am unsure if I did it correctly. I also have a boost pressure sensor that I tried doing the same with.

I also hear my boost control solenoid clicking like crazy the whole time that the car is running. It is a GReddy Profec solenoid that I have wired directly to the OEM harness plug. I am unsure why this is. I've tried setting this up as well in ECMLink, but am unsure if I did this correctly.

You must be logged in to view this image or video.

steve · May 3, 2026

You have made quite a few changes in ECMLink and given your comment I have to ask, can you justify each one? If you can great but if you can't then I suggest to return them to stock and only change what you're sure about.

For example you have added 5XX usec of additional deadtime to the InjBatteryAdj DA table but you're subtracting 500 usec in the Global deadtime Fuel Tab. There is no question that FIC 2150 Injectors need extra deadtime but the net effect of your setting almost nulls out any.

You have changed the LoadScale DA table to 82.8% but it looks like a 2.0L from your profile.
You have modified the SDTempWeighting DA Table but you're not setup for Speed Density.

During cranking you battery voltage falls to around 8v. Is that because it's not charged or because you have a grounding issue. As soon as the RPMs start to drop your battery voltage also drops to below 12v

You need to enable the Narrowband O2 simulation since you have the AEM WB inputting on the Front O2.
You have the MAP sensor configured as a GM 3 Bar not an AEM.
You shouldn't be locking the IAT and Baro parameters since you still have a 2G MAF configured in MAF Comp Tab. Since you have put you MAP sensor on the MDP input you want to lock that instead.

What ECU are you running? A 95 EPROM or a 97 converted to EPROM for ECMLink? I'm assuming you have a 2Gb CAS but you haven't enabled the non-95/96 CAS support in the Misc Tab.

tschuhly · May 3, 2026

steve said:
You have made quite a few changes in ECMLink and given your comment I have to ask, can you justify each one? If you can great but if you can't then I suggest to return them to stock and only change what you're sure about.

For example you have added 5XX usec of additional deadtime to the InjBatteryAdj DA table but you're subtracting 500 usec in the Global deadtime Fuel Tab. There is no question that FIC 2150 Injectors need extra deadtime but the net effect of your setting almost nulls out any.

You have changed the LoadScale DA table to 82.8% but it looks like a 2.0L from your profile.
You have modified the SDTempWeighting DA Table but you're not setup for Speed Density.

During cranking you battery voltage falls to around 8v. Is that because it's not charged or because you have a grounding issue. As soon as the RPMs start to drop your battery voltage also drops to below 12v

You need to enable the Narrowband O2 simulation since you have the AEM WB inputting on the Front O2.
You have the MAP sensor configured as a GM 3 Bar not an AEM.
You shouldn't be locking the IAT and Baro parameters since you still have a 2G MAF configured in MAF Comp Tab. Since you have put you MAP sensor on the MDP input you want to lock that instead.

What ECU are you running? A 95 EPROM or a 97 converted to EPROM for ECMLink? I'm assuming you have a 2Gb CAS but you haven't enabled the non-95/96 CAS support in the Misc Tab.

Thank you for all of this!

So I suspect that the person that owned the car before me did a bunch of attempted tuning. I'm hesitant to go in and reset everything back to stock because I do realize that there are a lot of upgrades on the car and I am not sure what needs changed and what doesn't (i.e. wb, 272 cams, 2150cc injectors, etc.).

I am wondering if the person that owned it before me was planning on converting to SD and never did.

Are you suggesting that I leave things as is and only changed what you spelled out, or are you suggesting I reset back to stock and then make the changes you spelled out?

The only ones that I can possibly explain are:

-My local tuner (he is fairly well known) sent me numbers to input for my injectors just to get it running but I don't think he looked at everything else so that's probably why some of the fuel stuff looks correct.

-battery voltage probably drops because I was doing a lot of "key on" tests like adjusting TPS and when I went to start, the battery was dead so I hooked it up to a battery tender and grabbed dinner before coming back. That being said, it is also very possible that I don't have enough grounds hooked up since relocating the battery to the trunk.

-i do believe it is a 2gb CAS (the easier one on the passenger side of the engine).

-as far as what ECU, I assumed the stock one with ECMLink installed but I could be wrong.

You must be logged in to view this image or video.

steve · May 3, 2026

Interesting comments on the ECU's connector. I'm guessing there are change wires on the underside since I don't see any on the top.

My suggestion to people who acquire somebody else's project remains the same as when I had to go to customers sites when they had problems others couldn't solve. What happened before me is questionable, start from scratch and work forward. If you change something and it doesn't fix the issue than unwind it or you never know what resolved the issue when it's fixed.

So, save these logs, they can serve as a backup to this point in time. Reset the ECU back to stock, it's not as easy as it should be but needs to be 100% done. Then make your changes for what you know.

With a stock MAF your airflow is largely calibrated so you can work on getting the injectors dialed in. They are huge for running on gasoline so the idle pulse widths are going to be very short. Because the IPW's at idle are short in general deadtime has a dominating impact on fueling. It should be possible to use FIC's data for a InjBatteryAdj DA table but I'm not sure how they derive their numbers. If somebody else has a well sorted version that would be useful but sort of that I'd just start with the original factory values for the 450's and use the global to adjust until you get it right at normal battery voltages. That number is going to be positive since most aftermarket injectors need additional deadtime over the originals. Your starting fuel global would be from the basic ECMLink calculations based the pressure and fuel type.

Make sure your getting solid data from the MAP and Wideband in ECMLink that matches whatever gauges came with them.

I wouldn't try to do any "tuning" until you have the baselines working correctly. You should be able to get the car to idle properly with stock timing and fuel maps even with big cams on the MAF. Maybe not the best but it should start, idle and not die.

If this doesn't work then you can always go back using the saved logs and try unwinding one thing at a time keeping in mind the things that don't make sense as set right now.

tschuhly · May 3, 2026

I will go over right now and see what I can do! Thank you so much!

Doing anything with ECMLink always scares me since I don't know what I'm doing so the guidance that you are giving is very helpful!

steve · May 3, 2026

Before you do read up on how to get things back to stock because it's not as easy as it should be.

tschuhly · May 3, 2026

I found this on the ECMTuning website: https://www.ecmtuning.com/wiki/v3configs?s[]=stock

I also went into the direct access tab and reverted everything to stock settings.

Do I need to flip my CAS on the engine since I am using an EPROM ECU that seems to be out of a 95/96 with a 97 car? If so, this is what I think I have to change with my car after being reverted to stock.

Upgrade firmware of ECU (just to double check)
Invert CAS on engine, rearrange plug order from 4,1,2,3 to 3,2,1,4. Then check box in ECM Link.
Uncheck evap, cat and misfire tabs in DTC.
Disable narrowband sim and keep undefined in ECU input (or Make front 02 narrowband sim)? This one I have read can be either or so I am not sure what is ideal for me. I know that you said to enable narrowband so I will definitely try that and see what happens.
Add -72 deadtime to Fuel tab for 2150cc
Change wideband (front o2) and boost in ECU inputs tab.

tschuhly · May 3, 2026

Thanks again man! I was able to get it running and go for a test drive!

The Central Hub for DSM Community and Information

ECMlink Help with idle issue

tschuhly

Attachments

steve

steve

tschuhly

Attachments

steve

tschuhly

steve

tschuhly

tschuhly

Similar threads

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds