subtract cranking fuel for startup. The main problem is wiring. If positive wires supply different
circuits, the voltage will vary with current flowing through the common wires. As the injectors and
ECU are supplied by separate circuits it is very important to follow the wiring instruction during
installation. If you do voltage compensation at running voltages, it is important to supply the ECU
directly from the battery via a relay from the ignition switch.
10. Fault Finding
10.1 Faults and Remedies
10.1.1 The ECU yellow LED does not come on
1. The ignition wire does not have 12Volt
2. There is a short on the 5 Volt output from the ECU. The magnetic crank or distributor
sensor, TPS and MAP sensor use 5 volt. Check the wiring.
10.1.2 The Software does not connect to the ECU with the USB to RS232
Converter
1. Pin 1,4,6,7,8 & 9 must be broken out to operate. See RS232 Computer to ECU interface
2. The Baud rate must be set to 19200 in the Device Manager.
3. No Driver for this Device installed – The USB converter must have a driver CD which has to
be installed first.
4. Too high Comp Port allocation for the driver. See Changing the USB Comport in Windows
Device Manager
5. Faulty USB converter.
10.1.3 The engine does not start for the first time
1. Go through the Startup Procedure to ensure ECU operation is correct.
2. If you crank the engine and it does not want to start, disconnect the high tension leads at
the plugs one by one and see if there is spark on the plugs. If not:
a. Check if the green LED on the ECU flash while cranking. If not check the crank or
distributor signals. Gaps of magnetic pickups may be too large.
b. Check if the fuel and Coil relays pull in at ignition on. If not check that the numbers on
the relays are correctly wired.
c. Test if the coils have positive supply +12 Volt when cranking the engine.
d. Test the coil resistance from the 10 way connecter to see if open circuit.
e. Test the coil to see if faulty.
f. If distributor type check the spark at the coil HT pole.
3. If there is spark, take out one of the spark plugs. If it is dry it means there is no fuel. Check
for:
a. Ensure the fuel pump is running during cranking.
b. Test the fuel pressure by loosening a bolt on the fuel rail somewhere. Hold a rag over
the joint to prevent spillage. Keep a fire extinguisher close by.
c. Ensure that the injectors was checked and serviced if the engine stood for a long time.
d. Put your fingers on the injectors and feel if they pulse during cranking.
e. If not, check the software for milliseconds injector time. It should be more than about
5% during cranking.
f. If it shows zero milliseconds, check the map calibration, TPS calibration, fuel cut off
function settings.
4. If the plugs are wet it means there is fuel. Check the following:
a. It may be that the start fueling was too much and the plugs were flooded. Dry them
and try again. You can also push the throttle in completely and crank the engine till it
tries to start or the plugs become dry.
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