Cold start issue driving me crazy

tchertel · 02-23-2020, 01:35 PM

Hello friends,
I am seeking a little advice on my Stillen Supercharged 370z. A little background; after the shop installed the supercharger I was getting some P0300 CELs right out of the box driving it home on the box tune. I contacted Stillen and took the car to them and they tuned it for me on their dyno and then I had no issues for about a year. I was driving the car home from Vegas and it jumped and lurched a little like it lost fuel pressure and then came back and was fine, didn't even light the CEL. The very next day, on the cold start I could here the car popping and mis-firing and it gave me P0300. Once the car got through its' warm up cycle and idle was down I cleared the code and it ran fine, no problems. This was happening on almost a daily basis and when I checked the freeze frame data it showed only 13 seconds of runtime before throwing the P0300 code in closed loop. Finally, as a band-aid, I asked for a tune that would ignore the P0300 code (since no codes ever popped up after warmup) but I actually got a tune that turned off the mis-fire monitor all together. I am not really thrilled about having that off but it has band-aided the issue.

Now I am back to trying to find the issue because I want to change to TogGunz air-to-air cooler and since I live in CARB country I am thinking to try to get an exemption order for the TopGunz modifications but I know if I am to do this I need to have the car in 100% working order.

I have discovered on the live data that the car immediately goes into closed loop mode upon startup and from my understanding it should be in open loop until the ECU sees certain sensors are within temperature range. I have replaced A/F Sensors, the O2 Sensors and the MAFs with new extension cables. I have looked at the readings from the coolant temperature sensor and appears to be reading correctly.

Anybody have any other ideas or know of another sensor that could trigger the car to go closed loop ASAP? Or could Stillen have setup the tune to go closed loop right away and I am looking at the wrong things here? The other item I have seen happening more often as well, before the car is completely warmed up, is the idle with suddenly drop for maybe a second and pop right back up; I have seen this happen after the car is fully warm but it is happening almost every red light before the car is completely warm.

Sorry for the long post; I wanted to as much info out there as possible. I am at a bit of a loss so I am hoping some of the Nissan experts here might be able to help.

redondoaveb · 02-23-2020, 02:14 PM

I would go with an Ecutek tune from Seb at Specialty Z

ByThaBay · 02-25-2020, 01:50 PM

I can fix this send me a PM

Ultrakla$$ic · 02-25-2020, 02:54 PM

Quote:

Originally Posted by ByThaBay

I can fix this send me a PM

What is causing it??

ByThaBay · 02-25-2020, 03:02 PM

Quote:

Originally Posted by ByThaBay

I can fix this send me a PM

There are a variety of things that can cause the issue. I troubleshoot them on a case by case basis.

Ultrakla$$ic · 02-25-2020, 03:22 PM

Quote:

Originally Posted by ByThaBay

There are a variety of things that can cause the issue. I troubleshoot them on a case by case basis.

awesome that you'd reach out to this guy!

tchertel · 02-25-2020, 09:54 PM

I will reach out this weekend. Thanks for the reply.

INFmstrTech · 03-03-2020, 07:30 AM

I can attest that Eugene will be able to take care of your cold start issues! He has tuned my custom setup since day 1. You’ll be very happy!!

02-23-2020, 01:35 PM	#1 (permalink)
tchertel Base Member Join Date: Dec 2019 Location: California Posts: 66 Drives: 2014 SC 370z Rep Power: 5	Cold start issue driving me crazy Hello friends, I am seeking a little advice on my Stillen Supercharged 370z. A little background; after the shop installed the supercharger I was getting some P0300 CELs right out of the box driving it home on the box tune. I contacted Stillen and took the car to them and they tuned it for me on their dyno and then I had no issues for about a year. I was driving the car home from Vegas and it jumped and lurched a little like it lost fuel pressure and then came back and was fine, didn't even light the CEL. The very next day, on the cold start I could here the car popping and mis-firing and it gave me P0300. Once the car got through its' warm up cycle and idle was down I cleared the code and it ran fine, no problems. This was happening on almost a daily basis and when I checked the freeze frame data it showed only 13 seconds of runtime before throwing the P0300 code in closed loop. Finally, as a band-aid, I asked for a tune that would ignore the P0300 code (since no codes ever popped up after warmup) but I actually got a tune that turned off the mis-fire monitor all together. I am not really thrilled about having that off but it has band-aided the issue. Now I am back to trying to find the issue because I want to change to TogGunz air-to-air cooler and since I live in CARB country I am thinking to try to get an exemption order for the TopGunz modifications but I know if I am to do this I need to have the car in 100% working order. I have discovered on the live data that the car immediately goes into closed loop mode upon startup and from my understanding it should be in open loop until the ECU sees certain sensors are within temperature range. I have replaced A/F Sensors, the O2 Sensors and the MAFs with new extension cables. I have looked at the readings from the coolant temperature sensor and appears to be reading correctly. Anybody have any other ideas or know of another sensor that could trigger the car to go closed loop ASAP? Or could Stillen have setup the tune to go closed loop right away and I am looking at the wrong things here? The other item I have seen happening more often as well, before the car is completely warmed up, is the idle with suddenly drop for maybe a second and pop right back up; I have seen this happen after the car is fully warm but it is happening almost every red light before the car is completely warm. Sorry for the long post; I wanted to as much info out there as possible. I am at a bit of a loss so I am hoping some of the Nissan experts here might be able to help. __________________ 2014 370z Touring Sport, Stillen supercharger, cat-back and oil cooler

02-23-2020, 02:14 PM	#2 (permalink)
redondoaveb A True Z Fanatic Join Date: Apr 2017 Location: So. Commiefornia Posts: 6,297 Drives: 2014 Nismo Gunmetal Rep Power: 2684374	I would go with an Ecutek tune from Seb at Specialty Z Ghostvette, wideglideleon and Whjaxn17 like this. __________________ Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo 700+whp

02-25-2020, 01:50 PM	#3 (permalink)
ByThaBay Base Member Join Date: Aug 2011 Location: Bay Area, CA Posts: 237 Drives: 2015 370z Rep Power: 6724	I can fix this send me a PM turtle64b likes this.

02-25-2020, 09:54 PM	#7 (permalink)
tchertel Base Member Join Date: Dec 2019 Location: California Posts: 66 Drives: 2014 SC 370z Rep Power: 5	I will reach out this weekend. Thanks for the reply. __________________ 2014 370z Touring Sport, Stillen supercharger, cat-back and oil cooler Last edited by tchertel; 03-02-2020 at 05:59 PM.

03-03-2020, 07:30 AM	#8 (permalink)
INFmstrTech Base Member Join Date: Nov 2018 Location: Near Frisco, TX Posts: 42 Drives: 08coupe, 07sedan Rep Power: 6742	I can attest that Eugene will be able to take care of your cold start issues! He has tuned my custom setup since day 1. You’ll be very happy!! __________________ ‘08 coupe w/Stillen SC, Custom A2A, SD, ID1050x, e85, eagle rods, high temp coated pistons, P&P heads, JWT C2, manual swap, stage 2 clutch. EcuTek(Eugene)

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