Fuel cut problems @ 6000rpm R34 GTT RB3025

[lolo37]

Hi from France !

I experience a fuel cut at 6000 or 6500rpm (depending on the weather) each time I'm WOT.
It doesn't cut when I'm 50% throttle.
Second problem is that I must unhook the MAP sensor to make the car run smooth when pushing the throttle. If i let it hooked, when I push the throttle, the car goes lean (20 AFR) and engine falls and I need to push harder to make it go strongly in the RPMs. quite undrivable.

My setup :
R34 GTT car and loom and ECU AA502 manual trans.
RB30 forged
R33 stock head and R33 CAS (changed connections on the plug)
GTX3582R at 1.2 bar with 44mm screamer gate and 72mm interior exhaust.
Intake plenum greddy type + FMIC. (leaks tested) (2,5" piping on hot side, 3" on cold side)
Q45 TB
R33 TPS (from 0.22V idle to 3.8V WOT)
800cc injectors on RON 98 fuel.
Z32 MAF (I have a ford Lightning one unhooked because it doesn't work well for the moment)
Z32 MAF is 4.66V when it cuts and TP is 145 or 146.
Map sensor tested with the log and shows 27% on Atmospherical pressure and 50% under 1 bar or more. And 15% on idle. I suppose these are correct values.

The MAP sensor problem appeared after i had some fire on the exhaust side because I overheated pistons of the stock RB25 (head vent sent oil on manifold :/). Wires seem ok so I decided to go RB30.
after one year when it started again, the problem was here (first time with complete setup and nistune inside)

So I let you my map.bin and also 2 logs fo you to see. One in stream mode and the other one in tuner mode.
Any idea will be much appreciated as it is a month I can make the car run correctly :/

[timturboz]

experienced same issue about to post on my thread aswell he suggested the tables to adjust read mine

[lolo37]

Sorry, I didn't catch your sentence :
experienced same issue about to post on my thread aswell he suggested the tables to adjust read mine

Who is : "he" ?
What is : "adjust read mine" ?

Did you find a solution? Where to find your topic?

[Matt]

Try all rpm limits at 7500rpm, speed limits = 512kmh and boost counter tp, ttp = 255

I can hold at 7450rpm max load with no cuts on the bench doing this

[lolo37]

OK,

Sebastien "Morov" came yesterday for mapping.
He started a new map starting again from 0. From the "ER34 RB25DET AA502 MT" bin file.
And problem was over. But I don't where I went wrong on my file.
I will try to check.

So now the car pushes hard from 4 to 7500. We estimate the power between 500 to 550cv (maybe 600 maximum)

What I don't understand is why the FORD Lightning MAF is at 5V at 1.3 bar. And we don't have the 700 hp of the maf rating...
Dyno tomorow hopefully.

[timturboz]

I wasn't sure exactly what .bin file to pic for my stock tune to build off of I suppose I will try that one as I still had a cut just 15min ago on a drive.

[lolo37]

What is you engine setup ? car? parts?

[Matt]

Load your last tune as 'comparison image'

Use the magnifying glass icon to compare each map. Use the COPY icon and copy maps from comparison > main gradually into your working tune file

[bachig24u]

OK,

Sebastien "Morov" came yesterday for mapping.
He started a new map starting again from 0. From the "ER34 RB25DET AA502 MT" bin file.
And problem was over. But I don't where I went wrong on my file.
I will try to check.

So now the car pushes hard from 4 to 7500. We estimate the power between 500 to 550cv (maybe 600 maximum)

What I don't understand is why the FORD Lightning MAF is at 5V at 1.3 bar. And we don't have the 700 hp of the maf rating...
Dyno tomorow hopefully.

What size tube is the Ford MAF installed in to?

[lolo37]

It is a cobra lightning model 90mm inside.

[bachig24u]

Cobra and lightning vehicles have different maf's.

Whats the part number you purchased?

I have a lighnting MAF here that at 6500rpm on 26psi in a RB30, it reached 4.48v mark.

[lolo37]

What turbo have you got ?

part number of my maf is:
1L3F-12B579-AB
AFH90-02
2F05

I search on internet and found a guy who told this was the standard reference of his cobra.
But to make the car runs correctly, I had to tick the lightning model on the maf choice of nistune.
The cars runs good with that. but high maf values yes...

[Ben C]

Glad you have fixed it
Could you post your. bin file for curiosity?


I noticed in your first post you mentioned the map sensor was reading 15% at idle and 50% atmospheric, where is it plumbed in? In the stock location it wouldn't read any vacuum as it is in the crossover pipe near the bov. That could explain why you had to disconnect it, if it was plumbed to the plenum.

[lolo37]

Oh THAT seems to be the solution of my MAP problem !! Thanks.
I'll test that in few weeks. Thanks a lot for your notice !

Here's my been file

[lolo37]

OK Great, the map sensor works again, You were right, it wasn't plumbed were it should ! Thanks you.

But this hasen't resolved my other problem : here is a short youtube clip to show you...
https://www.youtube.com/watch?v=-UCZZ89STNI

This is really anoying when the engine has stoped after an handbrake and willing to WOT!

Any ideas?