Mercury EFI

If the sensor in a pull down circuit is removed from the harness with the key on, the pcm will report _________ at the analog to digital convertor for that sensors circuit.

0v

If the sensor in a pull up circuit is removed from the harness with the key on, the pcm will report _________ at the analog to digital convertor for that sensors circuit.

5V

What number in the in the Equivilence Ratio/PHI Table represent a richer air/fuel ratio than the stoichiometric ratio? A Any number lower than 1 B 1.00 C Any number greater than 1

Any number greater than 1

What three sensors give the ECM/PCM the information necessary to perform the Speed Density? (some earlier non-current systems may only use two of them and a default value for the third) A CPS, CMP, IAT/MAT B CPS, MAP, IAT/MAT C ECT,TP, IAT/MAT

CPS, MAP, IAT/MAP

Speed Density electronic fuel injection systems ___________ the actual oxygen content in the air, they do truly measure it.

Calculate

The ECM/PCM only understands ____________. It does not understand temp. pressure or RPM

Counts

Sensors that monitor temp such as the ECT and IAT/MAT are primarily used by the ECM/PCM to modify:

Fuel

As engine load increases toward maximum, spark timing is reduced. This means it occurs: A further before TDC B closer to TDC

Further before tdc

The analog to digital converter: A How the ECM converts voltages into computer language it can work with internally and. where counts are calculated B Necessary only in DTS applications C able to. easily and inexpensively be replaced when it fails D none of the above

How the ECM converts voltages into computer language it can work with internally and. where counts are calculated

Why can a short or open on a single wire effect multiple circuits?

If they share the same common ground

A MAP sensor circuit sensor has failed in range. The MAP sensor is reporting very low load while the engine is running under a high load. The engine will most likely: A run just fine, the ECM/PCM will know how to adjust B Run incorrectly because it is receiving incorrect fuel and timing C run poorly only when it is initially started and warming up D none of the above

Run incorrectly because it is receiving incorrect fuel and timing

When an engine is accelerated, info from the ___________ sensor is used by the ECM/PCM to increase the fuel injector pulse width to add additional fuel needed for the acceleration event ( acts like an accelerator pump input)

TPS (throttle position sensor)

The term Stoichiometric always means: A 14.7:1 B The air/fuel ratio where best power is produced C The air/fuel ratio where complete combustion occurs and emissions are cleanest D The air/fuel ratio that burns the coolest

The air/fuel ratio where complete combustion and emissions are cleanest

E15 has been installed in an open loop EFI system. The engine will run: A Too rich B Too lean C The same D It won't run at all- it will most likely result in a crank/no start condition

Too lean

Closed loop EFI systems can run in open loop mode all the time. A true B false

True

When we discuss airfuel ratios, they are measured in parts of air to parts of fuel by: A volume B Weight C Cubits D Stones

Weight

Gas burns at a constant rate. Because of this, spark timing must be _________ as. engine RPM increases.

advanced

An engine is started cold and the ECM begins monitoring the. coolant temp. sitting at idle, the fuel injector pulse width will _________ as it warms up to operating temp. A stay the same B decrease C increase

decrease

The ECM/PCM sends a 5v reference voltage to many _______________ and receive a signal/sense voltage back.

sensors