I got my car tuned a few weeks back and I've had this really bad idle surging issue that my tuner is having trouble figure out. Also wont idle when the car is cold. Anyone else come across this issue? It didn't have the issue when the stock ECU and MAF were on the car. Did he maybe miss a setting that needed to be changed in the ECU? I already replaced both cam angle sensors and IAC sensor and still the same results

I posted my dyno graph and video I uploaded on YouTube at the very bottom

Car made 746hp and 576tq on e70 at 38psi


Short mod list:

Zeitronix wideband is wired to ECU and being used as the primary o2 sensor (deleted the stock pre cat o2 sensor)

Built 2.3L stroker 9:1
AEM V2 with stainless AEM 150 psi MAP sensor and IAT sensor
standard mounted PTE V2 6466 kit
AMS F1 intake manifold
Bomba 75mm throttle body
GSC S3 cams
Walbro 450 double pumper (15psi hobbs on second pump)
Primary pump rewired with STM kit
-8AN feed
-6AN return
Fuel FPR set at 35psi at idle

 

video is private

 

Sorry I just fixed it

 

You also need to put some thread sealant on the bolts that hold the throttle body on. They thread all the way into the intake manifold. You can get a boost/vac leak there.


To get your CAL you just need AEM Tuner installed on your computer. Plug your ECU into your laptop and after it is done connecting, do a file save and save the cal to your desktop. You can also just take some screen shots of the fuel map, and ignition map. If it will not cold start the startup enrichment tables need to be adjusted, and or you need to put new plugs in the car. If you are E85 make sure your are running a 7 or 8 heat range plug.


I am in corona/eastvale if you want to come down here I can take a look at your cal, and see if I can give it a little love.

 

Okay thanks @TheBoz. I'll check that out tomorrow. I bought the intake manifold and throttle body together used so I'm sure the previous owner didn't do that. I did a boost leak test a bit ago and did find a couple leaks on my Sheepybuilt lower intercooler pipe and ETS upper intercooler pipe. Fixed the leak in the upper but need to replace a clamp on the lower. Its not sealing no matter how tight I go. They use cheap T-bolt clamps with their kits so I'm hoping a Breeze clamp will solve that issue. Praying its just a bunch of boost leaks thats causing the issue.

My tuner was telling me that with the GSC S3s I have to degree my cams so it will run better? I didn't think that would cause this issue though?? Figured you'd only do that to gain more power up top or down low depending which way you defree them?

 

On speed density the leaks do t matter as much. But anything past the throttle body will affect the idle.

You might need to adjust your idle feedback settings, or adjust your timing at idle. If your afr is all over the map that will kill your idle. You should also have your idle about 1100 on the s3's.

 

We set the idle around 11-1200rpm. He said he had to richen it up at idle for it to calm the surging. Its in the 11afrs at idle. I know thats not right at all

 

Also you should consider going back to a stock curt brown ported intake manifold. My car got a fatter mid range going from the AMS F1i to the Stock ported. There is a thread on here where someone picked up like 50tq by switching back to the stock ported, and lost nothing on the top.


The AMS part looks amazing, and does preform if you are in that 800+hp range. I made 702whp on 32psi with a CB ported IM and a bone stock throttle body.


https://www.evolutionm.net/forums/pr...rt-2-a-22.html

 

Agree with TheBoz, you need to post up your .cal file. There's a lot of things that will affect idle.

 

Basically, if you're running properly working injectors with equal flow, and the injector latency table is set up correctly, and the motor is mechanically sound, there should not be a reason why the car won't idle right. It's really not that difficult.

 

Thank you for your response! I'm a noob when it comes to tuning. Where do I get the .cal file from?

 

You need to have AEM Tuner installed on your laptop.


Plug in the USB to the laptop


Open AEM Tuner, use run as Administrator


After it has connected to File -> Save Calibration As...


Save to desktop.

 

Okay so I have it download, I selected run as administrator and when I open it it wanys me to open a workspace?

 

select anyone of them

 

upload your cal we then might be able to help you, idle surging, could be several things to look for in the fuel and timing map and idle option settings..