In the big bad wide world of car techy talk, we at Fusion MS like to think that when it comes down to it, we are pretty good. Simple reason being if we truly thought otherwise we wouldn't bother.

I start like this due to the easy way that through the Internet things can be taken out of context and used to imply something it didn't. In fact life for the 'tuner', even when trying to help can be pretty tough.  This is what spurred me on to write this FAQ on fuelling and the e-Manage blue, since I have read so much nonsense about this recently from people who claim to know all.

My statement: 

The e-Manage blue cannot remove fuel directly, this is the same for all piggyback fuel computers, including devices such as the Apexi S-AFC, Dastek unichip etc. The only exception to this is the e-Manage Ultimate, which I won't be covering here.

Some people can't seem to get their head around this, they will say but the e-Manage blue can remove fuel, you do so by reducing the values in the airflow adjustment table. This is correct - to an extent, but has its problems.

The problem is and I shall take Nissan as an example as its what I work with most, Nissan ECU's have a minimum injector pulsewidth. For ECCS this is known as the TTP Min and stands for Total Theoretical Pulsewidth Minimum. This value sets the absolute minimum pulsewidth the ECU will provide to the injectors, but what does this mean? Simply what this means is that once you have removed all the air and reached the point of TTP, no amount of playing around on the e-Manage blue will do anything to further reduce fuel entering the engine.

Lets see some real life situations: 

From the table above you can see two examples of cars running an e-manage blue. The table shows stock injector values followed by larger ones and the % increase. It then shows weather the stock ECU was able to maintain closed loop lambda at idle. (i.e. maintain a sensible AFR for emissions) The pulsar is quite remarkable in its ability to use larger injectors. As a rule we would never recommend anyone to upgrade to anything less than 700cc simply due to future proofing upgrades, and no more than 750, to guarantee injector control. However we have successfully used 800cc injectors in the past, that's a staggering 81% increase in flow over stock and the stock with the OEM ECU still enabling control over idle. By comparison the Almera GTi cannot even manage a 69% increase. With 440 cc injectors the is no control over idle emissions at all and no hope of getting an MOT. The e-Manage blue has done all it can do to remove air, but is beyond the limit of the standard ECU and its TTP Min setting. For your own information Greddy recommend a 50% increase over stock injectors as a maximum.

The other problem encountered with this kind of mapping (by altering airflow values) is that this is a major load sensor. If you install larger injectors, the e-Manage blue compensates as I have described by removing airflow, as well as this you will be altering the ignition timing (since its heavily based on airflow voltage) so you could find yourself as a result with engine knock. (less perceived load = more ignition advance = more likely to hit knock). Again something we have never heard others mention, fail to understand and again something that every other piggy back of its kind (except e-Manage ultimate - surprise!) is affected by. We have always been aware of this limitation and its a non issue for us. Be warned by what other so called experts tell you, and what rumours you hear.