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GoldenDragoon
01-03-2010, 06:03 AM
Just a quick question for the tuners....

Fuel cut is due to the standard system (pump and injectors) reaching their limit according to the ecu?

But if you swapped out the pump and injectors for larger units, then the ecu would over fuel?

So what if you just adjust the signal from the maf? Would larger pump and injectors work fine with standard ecu if you just adjust signal from maf to give desired a/f ratio? Would this be all that is required to stop fuel cut?

Kenneth
01-03-2010, 06:30 AM
Short answer is no, you can't just change the injectors, and no you can't just modify the MAF signal.

The reason being that the ECU has the injector size programmed into it, and the MAF is THE main load sensor... If you turk with it, then you screw up any load calculation that the ECU does (and it does lots)

There is plenty of information available using the search

VR4WGN
01-03-2010, 07:48 PM
hi and welcome....as Ken says...but expecially under the "members section" is alot of usefull info for you boys

Turbo_Steve
01-03-2010, 10:16 PM
Or you could hit the googles with the search term "MAF bypass pipe".

Nick Mann
01-03-2010, 10:53 PM
The ECU effectively makes the decision for fuel cut based on the MAF. Stock injectors with a good pump and AFR should be capable of supporting close to 400bhp. It's just that the cars ECU isn't mapped for that kind of air flow.

Volchok
02-03-2010, 01:48 PM
I suppose you should use an Apexi SAFC to correct your MAF sensor indication.

Nick Mann
02-03-2010, 01:56 PM
There are lots of ways to play with the MAF signal.

There are two answers to the fuel cut problem:
1. Use a standalone ECU and program fuel cut where you want it.
2. Offset the fuel cut by providing more fuel than the ECU thinks is available and then alter the MAF signal down to suit. This method can introduce timing issues as well though, as stated elsewhere. This is potentially a cheaper way of doing it than option 1 although if you have the funds, option 1 can give you much more.

Turbo_Steve
02-03-2010, 01:58 PM
You can, but given the cost of the SAFC vs the cost of a bit of pipe to bypass the MAF, and the relative accuracy of the two methods...I know which I'd choose.

The problem with messing with the MAF signal is that you're always moving the ignition the wrong way.
Also, you're more likely to get a lumpy transition to open loop.

Turbo_Steve
02-03-2010, 01:59 PM
Nick - 3 methods, but Snap! :D


It's worth mentioning that now that the ECU remaps seem to be happening, there really isn't much point in using any other method: unless you're going insanely different, the factory ECU is generally your best bet once it's been flashed.