Eliminate fuel cut T5 Topic is solved

[madsking]

Hello everyone,

Raising boost pressure by using a bleed valve on a T5 stock ECU will lead to ECU fuel cut already at around 0.8 bar (or somewhere around that).
With the injectors upgraded I personally belive that the lambda sensor is able to adjust fuel inject level up to above 0.8 bar.

Question: Is there a way to manipulate the MAF so that it will not tell the ECU that boost pressure is too high and thereby cut the fuel?

Thank you very much in advance

Best regards
Mads

[abscate]

ME7 measures boost pressure directly with a sensor on the intake tube just before the throttle body. You could fool it there , the pressure voltage map is documented in VIDA

[scot850]

Except the OP is running a 96 850 T5, not a V/S70 so unlikely to be running ME7 and the car is not Vida compatible.

Neil.

[WhatAmIDoing]

I mean, my T5 that blew a motor would boost to the moon without fuel cut. And I'm not aware of the ecu being tuned. I kind of thought this was only a thing on ME7. Personally, if you already spent the money on upgraded parts, I would invest in a tune or learn how to tune.

[madsking]

Thanks so far
I am pretty sure the fuel cut is a standard thing. I am experiencing it the same way with different ECU's
With that said I am running a 16T which might supply a bit more air at lower rpms than the stock which could mean the fuel cut kicks in faster but anyway that could be a huge topic itself.
And absolutely true I could invest in a proffessional tune but I am not planning to go crazy and thinking about the design with the lambda controlling the air/fuel mixture which should be able to handle it for at least 1.0 bar which would be a perfect level for me and this engine.

Additionally do you know if the fairly cheap pre-programed chips on the market have removed or raised that limit for fuel cut?
That could be an affortable compromise.

I do know that a blown engine is also expensive

[WhatAmIDoing]

I am by no means a tuning expert, or even a novice. But the stock ECU is expecting stock injectors and a stock turbo running stock boost. It can probably compensate for slightly higher boost pressures but without a tune or a way to monitor AFR, it's hard to say if it will be safe. My experience is limited to 98-99, but I could hit 0.8bar ~12PSI without experiencing fuel cut. But I also don't know if those ECUs were tuned.

I am not aware of any way other than a tune to adjust fuel cut. This is probably a better question for the Swedespeed forum (don't hate me Matt).

[madsking]

Point taken I am also running white injectors and all together it of course confuses the ECU which you correctly say is expecting stock components..

[matthew1]

This is probably a better question for the Swedespeed forum (don't hate me Matt).

I don't hate you, WhatAmIDoing. But I want to make the point if we send users to SS, it'll never be a question for MVS, so it becomes a self-fulfilling prophecy.

If we talk about it here, or at least put down our findings, we'll have a more rounded set of data/opinions.

[matthew1]

As far as fuel cut goes, I never had it, and my '97 850 boosted up to ~17psi. I had swapped injectors though... I can't remember if I experienced fuel cut before the different injectors.

[Clemens]

I'd go for a tune by someone reputable. Anything else is gambling ...