If you have the means to do it then please do.Originally Posted by Nick Mann
You can do that with the MAP2 can't you Nick ?
No Glenn you can not remove the fuel cut with as at some point you will flow enough pseudo air through the system that it thinks that you need to fuel cut .
All you end up doing is shifting the point you hit it even with bigger injectors . Reflashing the ecu allows you to move it well out of the way of normal tunning
Really. Thought as you have the ability to go Mafless, u already have the ability to eliminate fuel cut. You have to build a New Map to go Mafless, so why can't u clamp the Maf sigmal below it's limit and build your own MAP above this point ?
This how it's done on the EMU.
EdIT..
Just re-read you post John. Understand ur saying it's only moveable to a higher point.
So what in the ECU is the limiting factor ?
Also would have thought on Standard Tub's that the Limit can be shifted far enuff to allow No Cut!
Last edited by Wodjno; 28-03-2010 at 06:40 PM.
I have not checked on the table as to how much load it will take before cut but I'd assume the maf limit will be around 319 which I doubt most vr4s will never see. If someone can send me a rom image I'll try locate the limit and raise it
The MAP2 sends and air flow signal to the original ECU. At some boost level, to get the right fuelling, the airflow the map2 needs to send puts it back into fuel cut territory.
If I understand it correctly, the emanage drives the injectors directly, whereas the map2 doesn't.
evonut - if I knew how to offset the fuel cut by flashing the ecu, it would already be done! I need to spend some time working out what cable and what software I need to do it. Then work out the tables so I modify the right bit!
Not sure I can give you a number. Fuel cut is most likely to arrive at 4000ish RPM at raised boost. It doesn't hit the end of the MAFs capabilities, it hits the part of the fuelling table where the ECU says "too much air - pull fuel to be safe".
Nick, fuel cut is movable with MAP2. I haven't got it since the MAP2 was put in.
Have a look at this extract from the V3.1 manual. Don't know if this is a revised feature from the firmware upgrade though. The full manual is available on the MAP2 website.
It means nowt to me but perhaps it will to you.
Last edited by apeman69; 28-03-2010 at 07:28 PM. Reason: No bl@@dy attachment... grrrr!
I know it won't be hitting the mafs capabilities and I have a rough idea where the boost limit is as I have a few vr4 maps with possible boost limit locations but no car to test them on. If the boost limit is correct the cut will hit around 160-170 load before boost cut. If someone can log the load at which boost cut occurs I can work from there.
I recall discussing this with Ben. I didn't really understand what he said, it is possible but very time consuming and tricky to get right..... I think?
Ignorance is bliss...
'97 Manual Legnum in silver with some subtle mods
My first VR4 - '97 Legnum Dark Green & mean ...it was love at first sight - now sold
The address for fuel cut is known within the VR4 rom , it is already in the xml files ( although it may be wrong depending which version you have )
Ape you can not remove fuel cut , as all you are doing is presenting the standard ecu with a lower figure than it should be to trick it into doing the correct fueling , even with 530cc injectors like you have at somepoint you will go beyond that limit
Evonut
Boost cut happens between 3500 - 4500 when the load table is around 0.48 bar for greater than 2 seconds , I have moved this to a higher region and it works fine
As I said in the othe thread you could try on my car
The mighty Leedsnum has gone but the Airtrek mods will soon fill this space
How To:Contact Committee or Moderators.
Ok so the cut delay timer is around 2000 ms can you point me in the direction of the xmls so I can compare with my own.
you already know where they are you live on the same site
geekmapped has a copy
Nut_Jo, Nick states that he wants to raise the limit and not eliminate it. Unless he is at the point where it cannot be moved further then there may be hope: that's all I'm saying. If he's reached the point where the next option is injector upgrades then fair enough.
BTW are you in danger of cutting your own throat here in terms of 'KinkyJohn the AfroNutter enterprises'? The Microsoft/Apple scenario comes to mind (you wish!). After all, who is this registered user evonut?
he resides on the geekmapped forum and mlr , hence i know of him
yes nick is running stock ijectors so has a lowering theshold than yours
You would have all found out that information sooner had you done a search...
Seriously though, it was published on these forums at least 3 years ago! Probably explains why it has fallen out of common knowledge I suppose.
AFAIK the MAP2 fuel cut defender is a voltage cap jobby for a hotwire MAF. The VR4 uses a frequency MAF instead, which the MAP2 can tune around but not fool. The only way of offsetting the fuel cut with a MAP2 is to lean the map at the point of fuel cut, effectively keeping the frequency below the fuel cut threshold. You can make this easier to achieve by increasing the fuel available at a certain injector duty cycle - this means you can input a lower frequency from the MAP2 to the original ECU, whilst having more air AND more fuel than the ECU thinks there is. The easiest way of doing this is to supply the fuel with greater flow/pressure, so a pump and pressure regulator mean that the same injector flows more at the same duty cycle. A more effective way of increasing the fuel is to increase the injector size, but that is not so straightforward and brings other complications. Either way, all you are doing is offsetting the fuel cut by fooling the ECU, not raising the fuel cut limit on the cars original map.
I think?!
Spot on Nick
And every time you do that, you end up with a little bit more timing as you head down the load scale.
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