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ECMlink Cold start surge/dies after tuning

CanadianTalonTC

Proven Member
459
10
Jul 8, 2011
Lethbridge, AB_Canada
EDIT: LOGS NOW POSTED

Hi there,

I had my car tuned a couple of years ago and since then I've had a cold start slow surge + dies. I can't seem to figure it out so hopefully one of you log gurus might point me in the right direction. Once warmed up it runs flawlessly and hot starts are fine. I've also attached a video of the cold start as well as a log warming up and once it reaches 140f.

The main issue is it goes to 1500 or so, runs well, starts to drop, leans out and dies.

Thanks for the help in advance.

2). Verified mechanical timing?
Yes

3). Verified base timing?
Yes

4). Ignition system
COP or Stock Coil: Stock
Wire brand and Age: NGK, 6 months
Spark Plug brand, type and Gap: NGK-BPR7ES at .028

If you are having electrical issues, you should follow the troubleshooting method inside the FSM (that you can download off this sitehttp://www.dsmtuners.com/threads/download-the-1g-service-manuals.344490/http://www.dsmtuners.com/threads/download-a-2g-service-manual.324090/) and post the resistance reading.

5). Motor health (Compression Test)
I haven't checked compression recently, it has about 6000km on the build if even, runs great otherwise.

6). Performed basic throttle body adjustments?
Idle Switch: Verified with Link
Throttle Cable: Yes
TPS: Yes to .63v with Link
BISS: Yes, hot it idles well.

7). Compression ratio
9:0:1

8). Any known bad sensors or brittle wiring?
No

9). Any DTC/CEL codes?
No

10). Electrical system
Car off (not running): 12.4 volts
Car running: 13.9 volts

11). Base fuel pressure and injector values
Base Fuel Pressure: 43
Injector Size (cc/min): 850 FIC injectors

12). Properly calibrated and configured wideband sensor
Sensor Brand: AEM UEGO
Calibration Date: UNK

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

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Attachments

  • Cold start.elg
    112.8 KB · Views: 3
  • Nearly warmed up.elg
    31.8 KB · Views: 1
  • Warming up.elg
    49.7 KB · Views: 2
Last edited:

curt-s

Proven Member
1,547
312
Dec 21, 2008
Winnipeg, MB_Canada
Looks like an O2 feedback problem of some sort.

The sensor may have a dead heater or the circuit could be troublesome, which means the sensor has to heat up itself by exhaust gas -- this will take a lot longer.
The ECU controls the O2 heater circuit so any problem with continuity or impedance should show up and register a code, at least, I would expect.
Alternatively, you could have a leak before the O2 housing sensor location that closes up once everything gets hot enough throwing off the cycle feedback.

If you have a spare O2 sensor, you could swap it in and see if it's just the sensor. Alternatively, you could swap your WBO2 into the front and plug the downpipe one with the " stocker" (assuming you run this configuration as it's most common) and simulate narrowband. I expect you're logging WBO2 so link can do that part for you.

I had this problem forever as well on my 1G with '95 ECU. It wouldn't go quite so drastic, but it would lean out to >16 until the cycle turns positive trim and it climbs back up to 13. Then, about 1-2 minutes into warm up, it just settled on its own and was fine until next cold start. I didn't have any leaks because my trims and VE were good and all my gaskets never showed a hint of carbon where it shouldn't have been, but I even tried to adjust the O2feedback DA to try and get it to smooth out.
 

CanadianTalonTC

Proven Member
459
10
Jul 8, 2011
Lethbridge, AB_Canada
Looks like an O2 feedback problem of some sort.

The sensor may have a dead heater or the circuit could be troublesome, which means the sensor has to heat up itself by exhaust gas -- this will take a lot longer.
The ECU controls the O2 heater circuit so any problem with continuity or impedance should show up and register a code, at least, I would expect.
Alternatively, you could have a leak before the O2 housing sensor location that closes up once everything gets hot enough throwing off the cycle feedback.

If you have a spare O2 sensor, you could swap it in and see if it's just the sensor. Alternatively, you could swap your WBO2 into the front and plug the downpipe one with the " stocker" (assuming you run this configuration as it's most common) and simulate narrowband. I expect you're logging WBO2 so link can do that part for you.

I had this problem forever as well on my 1G with '95 ECU. It wouldn't go quite so drastic, but it would lean out to >16 until the cycle turns positive trim and it climbs back up to 13. Then, about 1-2 minutes into warm up, it just settled on its own and was fine until next cold start. I didn't have any leaks because my trims and VE were good and all my gaskets never showed a hint of carbon where it shouldn't have been, but I even tried to adjust the O2feedback DA to try and get it to smooth out.
Thank you for your insight.

I tested the heater and I'm getting 21.9ohms on the sensor side and 12.39v from the ecu side with the car off so that seems good. I will have to wait until the car is cool enough to test the NB simulation. I got things tested and moved with only 1 significant burn from the exhaust manifold as well haha.

I have extremely minor marking near the V-Band of my wastegate but that's all for leaks. Can't imagine it's enough to affect anything.

I'll keep you posted and a new log next cold start. Annoying to tune something you can only run once every few hours LOL.
 
Last edited:

CanadianTalonTC

Proven Member
459
10
Jul 8, 2011
Lethbridge, AB_Canada
No change at all running the wideband as narrow 02. Got to be something happening within the open loop for sure though, I appreciate you narrowing that down. Suggestions appreciated, time for more reading as well.

Anyone reading, logs are in post 1 in the google drive link. I don't know why but I have no option to ad an attachment to posts.
 

TK's9d2TSi

Supporting Member
6,429
3,389
Sep 11, 2017
Cincinnati, Ohio
I haven’t looked at your log. I had a similar issue, cold start idle surge without it stalling. This turned out to be a stuck fiav. I had an extra one so I pulled it off and ran both under hot faucet water. The old one did not close all the way.

For adding a log. Are you selecting “add photo”, then “choose file”?
 

CanadianTalonTC

Proven Member
459
10
Jul 8, 2011
Lethbridge, AB_Canada
I haven’t looked at your log. I had a similar issue, cold start idle surge without it stalling. This turned out to be a stuck fiav. I had an extra one so I pulled it off and ran both under hot faucet water. The old one did not close all the way.

For adding a log. Are you selecting “add photo”, then “choose file”?
It kept throwing a file error, I wonder if it's cause I renamed the logs this time. Thank you for that, I cannot believe I could not get a file to attach LOL. They are in post 1 now.

I was wondering about the FIAV myself. This issue came about when the car was tuned, was fine before but stranger coincidences have happened. Would the FIAV also cause problems in open loop? (locked in open loop it starts and idles well).
 

TK's9d2TSi

Supporting Member
6,429
3,389
Sep 11, 2017
Cincinnati, Ohio
Not sure tbh and I didn’t try myself. It’s just one of those thing where you’d have to remove it to physically check and personally hate to remove the tb on dsm’s. It may not be your issue since yours is stalling. If you can’t find the issue, then maybe pull it off and check.
 

TK's9d2TSi

Supporting Member
6,429
3,389
Sep 11, 2017
Cincinnati, Ohio
TPS needs adjusted as it's only .49v. It should be .63 at 0% throttle and 5v at 100%. I would adjust manually and get it close, start the engine and recheck. If it's off by a few, then use the tps adjust feature in link.

 
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