hi,

I have a 2000 blazer 4dr with the check engine light on and it is very hard to start. It is idleing rough and there is also a strong fuel smell at times. The fuel pump was replaced about 2 years ago. I have gotten a code scanner and this is the info that I have from the scanner.

first check:

Stored:
P0172System Too Rich (Bank 1)
P0175System Too Rich (Bank 2)
P0300Random Misfire Detected
P0452Evaporative Emission System Pressure Sensor/Switch Low Input
P0453Evaporative Emission System Pressure Sensor/Switch High Input

Pending:
P0300Random Misfire Detected
P0453Evaporative Emission System Pressure Sensor/Switch High Input

MILON
MisFire MonitorComplete
Fuel System MonitorComplete
Comprehensive Component MonitorComplete
Catalyst MonitorNot Complete
Heated Catalyst MonitorNot Supported
Evaporative System MonitorComplete
Secondary Air System MonitorNot Complete
A/C System Refrigerant MonitorNot Supported
Oxygen Sensor MonitorComplete
Oxygen Sensor Heater MonitorComplete
EGR System MonitorComplete

DTC For Which Freeze Frame Was StoredP0300
Fuel System 1 StatusClosed Loop
Fuel System 2 StatusClosed Loop
Calculated LOAD Value3.53 %
Engine Coolant Temperature143.6 °F
Short Term Fuel Trim - Bank 1-0.78 %
Long Term Fuel Trim - Bank 1-3.13 %
Short Term Fuel Trim - Bank 2-0.78 %
Long Term Fuel Trim - Bank 2-3.13 %
Intake Manifold Absolute Pressure11.2 inHg
Engine RPM681.25 rpm
Vehicle Speed Sensor0.0 mph
Air Flow Rate from Mass Air Flow Sensor0.837 lb/min
Absolute Throttle Position0.00 %

second check:


Stored:
P0300Random Misfire Detected

Pending:
P0172System Too Rich (Bank 1)
P0300Random Misfire Detected
P0453Evaporative Emission System Pressure Sensor/Switch High Input

MILON
MisFire MonitorComplete
Fuel System MonitorComplete
Comprehensive Component MonitorComplete
Catalyst MonitorNot Complete
Heated Catalyst MonitorNot Supported
Evaporative System MonitorNot Complete
Secondary Air System MonitorNot Complete
A/C System Refrigerant MonitorNot Supported
Oxygen Sensor MonitorNot Complete
Oxygen Sensor Heater MonitorNot Complete
EGR System MonitorComplete

DTC For Which Freeze Frame Was StoredP0300
Fuel System 1 StatusClosed Loop
Fuel System 2 StatusClosed Loop
Calculated LOAD Value3.92 %
Engine Coolant Temperature188.6 °F
Short Term Fuel Trim - Bank 1-30.47 %
Long Term Fuel Trim - Bank 1-17.97 %
Short Term Fuel Trim - Bank 2-30.47 %
Long Term Fuel Trim - Bank 2-17.97 %
Intake Manifold Absolute Pressure9.8 inHg
Engine RPM880.50 rpm
Vehicle Speed Sensor26.3 mph
Air Flow Rate from Mass Air Flow Sensor0.884 lb/min
Absolute Throttle Position0.00 %


I don't have a factory service manual and I'm not sure where to go from here. What would cause the blazer to act up this way??? The blazer broke down and wouldn't start earlier this week. I'm concerned that it will happen again.

Thanks for your help. I'm sorry about the long post.

mike

 

If you have a "strong" smell of fuel there could be a few things to check. Remove the air intake hat from the throttle body and rotate the throttle blade, smell for gas. If there is still a strong smell you could have a leaking fuel pressure regulator (mounted to fuel meter block [spider injector]). It could be a leaking fuel meter block (bad o-rings for injectors inside the block), or a sticking poppet (common problem). GM redesigned the meter block to reflect warranty issues with the poppet valves, they now are more like the LS1 Camaros with an injector mounted in the intake manifold at the end of the fuel supply tube from the fuel meter block.

This should give you some things to look at...