Haltech E8 - Manual (Page 81)

Haltech E11/E8 Instruction Manual
Warm the engine up to operating temperature.
Adjust the idle control or throttle stops to enable the engine to idle at the desired engine speed.
While watching the A/F meter, adjust your idle mixtures as lean as possible whilst ensuring that you can
maintain a steady idle without any misfiring.
While leaving the engine un-loaded, rev the engine in neutral through the rev range over which the engine
will be operated. Set all the mixtures close to 14.7:1 in the non-loaded part of the load range.
With the aid of a dynamometer or an alternative method of applying load, step through the load range for
each given RPM range and adjust your A/F ratio to suit. See the following sections for more details on
tuning the various ranges of the base maps.
Tuning for Idle
The idle mixture is very sensitive to correct bar height. Idle injection times are usually around 1.5 to 2.5
ms. If the injection time at idle is much lower than this, it may become difficult to set accurate idle and
cruise air/fuel ratios.
If the engine is hunting at idle, then the map is probably too lean, particularly at the 500 rpm point. Watch
the movement of the map arrow carefully. The map arrow should remain stable while the engine is idling.
If the arrow is moving excessively in a MAP based system, then it may be necessary to use the Zero
Throttle Map.
Remember that the ECU interpolates against both rpm and load. If the engine is idling at 800 rpm, then
the injection time is computed as 60% of the value from the 1000 rpm range, and 40% of the value from
the 500 rpm range, so both ranges would have to be adjusted to get the correct mixture. Similarly, if the
idle mixture is reacting poorly to changes of the bar indicated by the map pointer, then try adjusting the
adjacent bars. Wait for the engine to heat to operating temperature before performing further changes to
maps.
Tuning With No Load
Using the throttle only, increase the engine speed to 1000 rpm. If the engine is at exactly 1000 rpm then
only that range needs to be adjusted. Adjust for the crispest engine response. Engines will usually idle
rich, then head towards stoichiometric mixture at higher speeds. Repeat for 1500, 2000, 2500, 3000 rpm
etc. The engine should now start and fast idle evenly. You should also have the engine running at
operating temperature before doing any tuning of the base maps. Go to the Engine Data Page at this point
and check all the sensor inputs are reading correctly, and that the temperatures have stabilised before
continuing.
While free revving at higher engine speeds, check the engine speed on the computer. If it becomes
erratic, or fails to follow the actual engine speed correctly, check Section 2 on setting the trigger.
Applying Load to the Engine
Once the engine has been tuned properly for no load conditions it is possible to begin loading the engine.
The best method of applying load to the engine is using a dynamometer. However, if access to a dyno is
not possible the engine can be tuned on the road.
On the Dyno
Whether the vehicle is on a chassis dyno, or the engine on an engine dyno, the principles of programming
the Haltech ECU are the same. Take the engine rpm up to 1000 and apply partial load and adjust the
1000 rpm range. Return the engine to idle and on the 1000 rpm range adjust the bars to draw a straight
line from the idle point through the part load setting tested. Continue, adding more load, up to the full load
settings. This should be a fairly good approximation to the required curve. Repeat this for the 1500 range,
2000, 2500 etc. The engine should be fairly drivable at this point.
Copyright © Haltech 2008 Page: 81
WARNING
To avoid engine damage, an engine should always be tuned rich then slowly leaned
out until the desired AFR is reached.