Haltech E6GMX - Manual (Page 53)

E6GMX Manual
53
5.5.4 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 mixtures.
If the engine is hunting at idle, then the map is probably too lean, particularly in the 500rpm
range. Watch the movement of the map arrow carefully. The map arrow pointer 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 refer to 4.5.5 Zero Throttle
Map, p47.
Once the engine will idle it is a good idea to wait for the engine to reach operating
temperature before performing further changes to maps. This can be established by checking
the coolant temperature reading in the engine data page.
5.5.5 Tuning with No Load
Using the throttle only, increase the engine speed to 1000 rpm. When the engine speed is
exactly 1000 rpm the ECU will use only the bars in the 1000rpm range for fuelling
calculations meaning no interpolation from adjacent ranges will affect the mixtures. Repeat
this process for engine speeds 1500, 2000, 2500, 3000 etc. The engine should now start and
fast idle evenly. 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 engine data page.
If it becomes erratic, or fails to follow the actual engine speed correctly, check the trigger
wiring and make sure that the information in the ignition set-ups is correct. If you continue to
have problems refer to the troubleshooting guide in the appendix.
5.5.6 Loading 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.
5.5.6.1 On the Dyno
Whether the vehicle is on a chassis dyno, or the engine on an engine dyno, the principles of
programming the Haltech E6GMX 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.
Full load tuning should be approached with caution. An engine at full load that is too lean
may begin to detonate and destroy the engine. Before loading the engine, increase the heights
of the right-most bars so that they are higher than the line projected by drawing a straight line
from the idle and free-rev settings and through the part-load settings.