R34 GTT Stall on launch acceleration.

[MakkaPakka]

Hi SAU,

As the title suggests, I'm having a weird issue with my 1998 Skyline R34 GTT Auto. Essentially the car will stall out on me when I accelerate maybe past ~10%  throttle at a launch or even turning around a carpark at very slow speeds etc, leading to some semi awkward moments. Car will drive and accelerate fine once it's rolling at say 15km already, I can flat foot it and it'll boost and zoom at full power. Doesn't matter if I'm in Tip-Tronic or leaving the car in "D".

 

Mods currently on the car that are related:

GTX3076R Gen I Turbo

TurboSmart Kompact plumback

450LPH Fuel pump

Nistune

3" Catback with stock down pipe and cat.

 

Initially the car had a 100% atmosphere BOV which cased stalling/lugging once coming off boost, took the car to PZP and they sorted out that issue by chucking the TurboSmart BOV on there and re-tuned, currently at 316WHP. I've only had the car for a short period so I'm not sure if the plugs/coils or fuel filter have been changed recently, but I'd like to think they would of shown issues during the dyno tune. I'm new to the RB game and their quirks, anyone have any ideas or possible suggestions?

I was going to swap out the filter this weekend and see what happens, but I doubt it's that as the car runs fine once at speed..

Thanks heaps! really appreciate it

Edited April 2, 2019 by MakkaPakka

[GTSBoy]

This is not an RB quirk.  You're either losing fuel or spark (either totally, or just enough to stall it).  You should get a laptop (with Nistune) hooked up to it and look at the feedback as you drive it to stall.

[RBW49N]

Or soft inlet tube/rubber getting sucked close on acceleration

[GTSBoy]

1 hour ago, RBW49N said:

Or soft inlet tube/rubber getting sucked close on acceleration

Except that he said it would go hard if it was already rolling, whereas a soft inlet collapse should prevent that too.

[MakkaPakka]

7 hours ago, GTSBoy said:

This is not an RB quirk.  You're either losing fuel or spark (either totally, or just enough to stall it).  You should get a laptop (with Nistune) hooked up to it and look at the feedback as you drive it to stall. 

You're probably right, I'll try hook a laptop up and see what shows up! Thanks man

[Stick180]

Best way is to use nistune to do a log, from there you can work out what is going on

[RBW49N]

Except that he said it would go hard if it was already rolling, whereas a soft inlet collapse should prevent that too.

My Sylvia used to do it only on hard takeoffs just enough load to do it but when already moving it didn’t

[GTSBoy]

Worth a look then.

[Dose Pipe Sutututu]

Sounds like the Alpha N table isn't set properly, put it all at 255 across the rev range. If it's set under 255, on light throttle there's a massive surge of acceleration compensation that's applied.

Also is the stock MAP sensor connected? Nistune goes spastic with it disconnected even though the flags for the sensor are disabled.

[MakkaPakka]

On 4/6/2019 at 2:44 PM, Dose Pipe Sutututu said:

Also is the stock MAP sensor connected? Nistune goes spastic with it disconnected even though the flags for the sensor are disabled.

MAP Sensor is still connected.

Thought I'll give a quick update incase others have a similar problem, had a mate look over it.

Throttle body was pretty gunked up, but also started throwing an engine light for the TPS being shot. Gave the TB a little clean and it helped a bit, car would launch fine from a complete stop but then come an hour or so later it may stall or hesitate, then go back to normal. So the issue became intermittent instead of a 100%

Tried clearing the code but it came back. So at this stage, looks like the TPS and gunky Throttle body could be the problem. I've yet to replace the sensor so I can't say just yet.