The trouble shooting on fuel consumption

1. The trouble shooting on fuel consumption
1. failure phenomenon: engine power is good, but the fuel consumption is too large, accelerated
pipe smoke.
2. the cause of the problem
(1) the water temperature sensor disorder;
(2) the air flow meter or intake manifold pressure sensor disorder;
(3) throttle position sensor disorder;
(4) the fuel pressure is too high;
(5) cold starting fuel valve leakage or cold starting control disorder;
(6) injector oil leakage.
3. fault diagnosis and elimination
(1) testing temperature sensor, the different temperature resistance should be ds708 standard.
Resistance is too big, can make the computer as engine in low temperature condition, and thus
for the cold car crowding control, fuel consumption increase. Also can use the computer fault
detector to detect, it can display the temperature in the engine is running sensor to the
computer signal that water temperature value, the value and the actual engine temperature
phase comparison, can intuitively reflect the water temperature sensor are working properly.
(2) the test air flow meter or air inlet manifold absolute pressure sensor, and its numerical should
comply with the standard. Air flow meter or intake manifold pressure sensor error will directly
influence the fuel injection quantity. Test results if there are any complications, should be
replaced air flow meter or air inlet manifold absolute pressure preach
Sense organ.
(3) check throttle position sensor. In the throttle in medium and small opening, full load switch
contact should be off. If the full autel maxidiag load switch contact always closed or closing time
early, can make the computer always or prematurely to full load and thick, so as to increase fuel
consumption.

2. (4) measuring fuel pressure. Idle when the fuel pressure should accord with the standard value,
with the opening of the throttle, fuel pressure should be gradually rise, throttle open when the
fuel pressure than idling about high fifty kPa. If the fuel pressure with throttle opening change
and change, but the pressure is always on the high side, is that oil pressure regulator has fault,
should be replaced. If the fuel pressure can't with throttle opening changes. Is that oil pressure
regulator of the vacuum hose rupture or fall off, or fuel pressure regulation control
electromagnetic valve has fault, make the intake pipe vacuum no effect in the oil pressure
regulator vacuum diaphragm cummins inline chamber, resulting in oil pressure is too high. In this
regard, we should replace hose or electromagnetic valve.
(5) check the cold start injection control is normal or not. Using a multimeter to voltage block or
try to light up in cold starting fuel injector wiring harness connector, check the engine start when
cold start injector work duration whether accord with standard. If working time is too long or has
been starting work, then
That cold starting fuel injection control disorder, should check the cold starting temperature time
switch and control circuit.
(6) remove the fuel injector, check the fuel injector for oil leakage. If there are any Cummins
INLINE 5 complications, should clean or replace fuel injector.
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