BRZ down... Stalls right after start
 

The BRZ I bought about 2 months ago came with the following condition:

You start, it runs for about 2 secs then it stalls. The second time you start it always runs fine. Condition went away for about 2 weeks.

But today, when I was 2 hours away from home, instead of starting after the 1st try, it kept doing the same thing over and over. For nearly 20 minutes. I took an uber ride to an appointment, came back an hour later and the same thing kept happened.

As the tow truck was headed my way, it started, I drove to a dealership and left it there.

It NEVER EVER stalls after it's running. It runs insanely great. Nobody has any idea what's going on...

Anyone?

Does the car have any power mods .... ??

How many miles on it .. ??

My first "guesses" would be related to a fuel problem.

* water in the gas

* clogged fuel filter


humfrz

Does it still stall if you have your foot on the throttle while you start it?

Wait for your dealership diagnosis. Surely there's something they'll point to as the problem.

I'm not a mod guy. When I bought it the dealership said they had reset the ECU to factory. The only mods we know of is the air filter and inlet take hose which gets rid of the resonator. They gave me a "certified" pre-owned warranty till 100k, and right now the car has 45k.

Yeah, I tried revving it for those 2 secs it's on to see if it still stalls and it does. It feels like the computer is deliberately cutting the gas. It has never once stalled when it's running, even at the 500rpm idle ;)

Dealership thinks it's the immobilizer antenna unit...

I would check the clutch sensor. It is a little switch that when you press the clutch it allows the car to start. I have seen this in several brz around me. It's an easy fix.

It bothers me that the dealer said they reset the ecu to oem. If it had been flashed before maybe something didn't get put back on right.

I'm with humfrz could also be fuel filter.

I would think if it's the immobilizer ant that it would either work or not.

I don't think it's the clutch sensor because the car does start. It runs for 2-3 seconds until power is cut off.

If it drives fine once it runs, the only real ignition coil trouble you could have is bad coil boots. But that would resolve with more throttle.

A failing fuel pump doesn't typically behave the way you're describing.

There is a host of other little mechanical things that can cause a car to start and die; sticky throttle bodies, vacuum leaks, fuel filters/regulators, etc, but I can't think of one where the car would still run flawlessly once it started.

I'm leaning towards it being a sensor issue. Most likely MAF or O2 related. Take my advice with a grain of salt but that's where I'd start looking.

I have the exact same problem.This is the only thread I found.
Push start brz 2016 20000Km. Overhere. No mods. 110% stock No codes. Daily driven.
NOTHING out of the ordinary. Normal/spirited driving
Always(almost) fuel up at the same Shell station.

It happens randomly. Hot or cold, left, right or center. It starts, runs for 1- sec. then blah! It just dies. no burps, studders, just instant death. Like the ECU is going oh hell no you're not! Press the button again and it starts back like everthing's honky dory and runs so for weeks/months.

Bothered, the dealer will obviously find jack squat is wrong.
I doubt "Shut up and give me a free ecu Reflash" would work well.

There no updated ecu firmware for any car past mid 2013


Of you have diagmostic toll check the long term fuel trims at idle valies over 10% isually indicate a problem like intake or exhasut leaks


Check the map manifold pressure sensor reading with ignition on but engine stopped should be 1 bar ie armospheric or 14psi, when engine idling should be about 0.3 bar or 4psi. If it wildly different then again you may have air exhaust leak or the map sensor is faulty.


Also try cleaning MAF mass air flow sensor


Check afr at idle is aprox 14.7

BRZ down... Stalls right after start
 

Because you say it starts perfectly fine without hesitation and is perfectly smooth I’m going out on a long limb and thinking maybe something related to the immobilizer system. I’m not sure about the Twins but on cars I’ve had in the past they would actually start and run for a few secs before the computer would shut it off because it wouldn’t see the transponder. I actually have a key that isn’t paired yet. I will give it a test for shits and giggles.

Edit: Oh never mind missed the part were you said it runs fine the second start.