N300+ Revs drop when touching throttle

[DUZ32]

Log 2023-10-22 12_09_36 pm.llg

Hi

I'm setting up the G4+ for the first time. Starting from the base tune, it idles ok until I touch the throttle in any way and it will bog down, revs stall and then bounce around after I stop applying the throttle.

I installed 740cc injectors, so have adjusted the fual main down to 7ms to start with. TPS kept reading either 1% or slightly higher after calibrating, so I have increased the idle cut off to 2% in the attached log. 

IACV was working before installing the G4+, so I don't think it's that. Overall was running well before and have only changed the injectors. Stock 300zx fuel pumps are meant to be capable to handle this size and it's happening as soon as I apply a small amount of throttle. 

Any help would be much appreciated. Hoping to get it running enough to drive to have it tuned properly. 

cheers

Dave

 

[Adamw]

You are shooting in the dark trying to tune fuel with no wideband, but sounds like it is way too lean.  I would expect master to be up around 10-15 for 750cc injectors, try increasing it to see if it responds better or not. 

[DUZ32]

Thanks for the response, Adam. The logic for the 7ms was only based on it being 15ms in the base map and 740cc injectors are twice the size of stock. I'll try increasing to see if it stabilises.

I'll be getting a few other jobs done when I take it to be tuned. Was just hoping to avoid multiple trailer trips.

[DUZ32]

I just tried it and it's night and day better. You were right. Thanks very much.