I assume it doesn't but for some strange reason would the ECU+ get rid of fuel cut? Im assuming it can't considering the ECU is what cuts the fuel and the ECUplus just kinda tells the ECU what to do in regards to timing, fuel and airflow.

Another question would be is there ANY way to get rid of fuel cut aside from reflashing? Would raising the fuel pressure above stock levels and leaning it out work?

 

Also, could someone please let me know exactly what fuel cut is... I understand it is the ECU cutting the fuel but I am interested in knowing exactly when and why it will do it. Is it when you get to a certain percent injector duty? Is it purely based on airflow? How does it work?

 

the fuel cut I think of, is what happens when you over rev the motor. the ecu cuts fuel delivery and spark so that the rpms don't go past the 7600 or so rpm limit.

an expensive piggyback or standalone allows you to UP the rpms if you want, maybe the ecu+ does too.

 

You can adjust the maf frequency with ECU + and that will eliminate fuel cut.
Im pretty certain that fuel cut is based on airflow. Thats why most of the time when you have a stock EVO and you install a MBC and dont get a flash you can hit fuel cut often.

I assume you arent talking about the rev limiter. If you are talking about the rev limiter then no, ecu + does not change the rev limiter.

 

The only way you can eliminate fuel cut with the ECU+ would be by installing larger injectors. Fuel cut occurs when the amount of air passing through the MAS exceeds a threshold programmed into the ECU. With larger injectors, you scale back the MAS reading, making the ECU think there is less air going into the engine and dropping the reading below the fuel cut threshold.

 

Alright, yes I am not talking about the rev limiter. I couldn't figure out what my problem was for a long time... I thought it was just running way too rich at 4,500 but then I figured out it is probably fuel cut... My airflow obviously is lower at 4500 than at 7000 but for some reason it cuts out at 4500. Thats why I didn't think it was fuel cut at first but now I am almost positive it is. Oh well, thanks guys

 

first off trinababe, are you using a MBC?.....fuel cut is there to prevent detonation...throwing larger injectors wont solve the problem....if you are cutting off at 4500, there is a number of reasons.....you need to elminate your options...

 

I'm not completely sure on this, but I think the ECU has a maximum airflow threshold for each RPM. I had issues with fuel cut around 4000-4500RPM before I got my flash because I was adding fuel with my AFC at those RPMs. I never had an issue with fuel cut at higher RPM, just around 4000-4500 because I was adding fuel. I turned down the boost a little to fix the problem, but larger injectors scaled with the AFC would have solved the problem as well.

-Paul

 

Sorry - I missed your question.

The ECU+ does handle fuel cut. Fuel cut occurs when the stock ECU sees a MAS frequency over a certain number of Hz. The ECU+ improves the situation in two ways:

1. Inherently, and especially with larger-than-stock injectors, people tune their car by reducing fuel. The ECU+ does this by reducing the MAS frequency that the stock ECU sees. So fuel cut will occur at higher power levels with the ECU+ than without - just because that's how it works.

2. The ECU+ has a "MAS frequency limit" setting. You set this, and the MAS frequency that the stock ECU sees never exceeds this value. So the idea is that you can set this just below where the stock ECU does fuel cut, and you'll never have fuel cut. Important, though, is that this has the side effect of possibly making the car run lean when this limit is hit. So when you use this feature, you log very carefully what's going on as you approach the limit. The ECU+ is one of the few systems on the market where you can actually see what's going on as you fiddle with this setting, so it's a lot more safe than some standalone box from HKS.

The way most people get rid of extreme fuel cut is to increase their injector size, and then tune out the delta with something like the ECU+, but increasing the fuel pressure will accomplish the same thing as getting larger injectors, up to a point.

Tom

 

You dont happen to know the exact hertz to rpm cutout.. ie; at 4000rpm hertz needs to be xxx to hit fuel cut, or at 6000 - hertz = xxx to hit fuel cut. Thanks

 

I could still use a different sensor with your ECU+ to look at my airflow after I surpass the specified airflow "limit" correct?

 

Not sure I understand your question, so here's a shot: the ECU+ logs "input" (from the MAS) and "output" (to the stock ECU) MAS frequency. You can limit the output frequency, while still seeing what frequency the MAS is generating. The best way to fiddle with this, though, is to use a wideband (the ECU+ supports many of 'em) to ensure that you're not running lean when using this feature.

Abut your previous question - I don't know the exact frequency for fuel cut. Seems like it should be easy to find, though, just floor the accelerator and when you hit it, you'll know!

Tom

 

lol I hit it too many times recently.. it has got to be hell on the drivetrain. I just dont floor it anymore

When are you going to get the knock thing done??? Im still waiting