Car stalls under Hard Acceleration / Boost

[Klmykvl]

Hi guys,

 

I've been searching around for a while to see if anyone has experienced a similar issue.

 

I have a Stock  series 2 RB25det in my 240z running on a wiring specialities pro harness. Stock ecu, HVLP to surge tank to Walbro 255.

 

The issue I am experiencing:

 

When going hard into boost (70% + throttle) the car will sometimes stutter hard. It feels as if the motor actually shuts down but if I coast for a few seconds with my foot off the throttle power comes back. I can ease into throttle and boost fine. The car will also sometimes die as I coast to a stop.

 

Here is what I've done this past week to try and resolve the issue:

 

New copper spark plugs gapped to .028

Verified timing is 15 BTDC

Cleaned the MAF

Calibrated the TPS

 

Has anyone experienced this issue before? Is there anything I've missed? Any help would be much appreciated.

[ihiryu]

Fuel cut?

[Klmykvl]

Turns out it was my tps wiring causing the issue.

 

Now I will sometimes have issues with the idle hunting or the engine stalling when coming to a stop sign. I am currently cleaning my IAC to see if that may help.

[wrcbonk]

Not sure what kinds of boost level you are running with the stock ECU. I have hit Fuel Cut several times running the stock ECU with too much boost pressure ~13 lbs or more). It's Nissan's way of saving the engine. I can't afford the engine management computer I want at the moment so I run modest boost pressure, ~ 9lbs, and use Royal Purple Octane Booster if I want to rev it out. The stock ECU timing table is set for 97 octane, it pulls timing and dumps fuel when the knocks start coming from fuel starvation or inadequate octane.

 

my 2 cents   

[Klmykvl]

Thanks for the info. I will have to look into that, as I am currently experiencing a code 34.