Fuel mileage problem and I'm about to sell
#11
07-21-2012, 09:25 PM
Have you thought about taking it to a mechanic with an engine analyzer? Not only could it be just about any sensor causing poor mileage but any wire or connector also. What you are doing we call throwing parts at a problem. If you play the odds and your car model has a common issue you have a chance of hitting something and fixing it but sometimes you just need a real mechanic. Some guy that has look at 6 other MAF sensors reading this week and know exactly what it should look like on his scanner. His scanner may show the issue and the fact that the sensor itself is not the problem.
There is no indicator that your plugs and wires are worn. Incomplete combustion is worse with load so even a good idling car can need plugs and wires. A scope is about the only way to test plugs and wires. Step one to any bad MPG job is to make sure all maintenance is up to date. Plugs wires filters then replace both primary O2 sensors. If it still not running right and the plugs have “Normal” wear on them then the car need to go on an engine analyzer. The plugs themselves can tell a mechanic what is going on at lease what was going on right before the motor was shut off.
The key to this is finding a good mechanic that works on driveablitly issues all day long.
On rare occasion bad MPG is not caused by the motor at all. It can be cause by sticking brakes or a slipping transmission.
There is no indicator that your plugs and wires are worn. Incomplete combustion is worse with load so even a good idling car can need plugs and wires. A scope is about the only way to test plugs and wires. Step one to any bad MPG job is to make sure all maintenance is up to date. Plugs wires filters then replace both primary O2 sensors. If it still not running right and the plugs have “Normal” wear on them then the car need to go on an engine analyzer. The plugs themselves can tell a mechanic what is going on at lease what was going on right before the motor was shut off.
The key to this is finding a good mechanic that works on driveablitly issues all day long.
On rare occasion bad MPG is not caused by the motor at all. It can be cause by sticking brakes or a slipping transmission.
#12
07-22-2012, 07:22 PM
Have you thought about taking it to a mechanic with an engine analyzer? Not only could it be just about any sensor causing poor mileage but any wire or connector also. What you are doing we call throwing parts at a problem. If you play the odds and your car model has a common issue you have a chance of hitting something and fixing it but sometimes you just need a real mechanic. Some guy that has look at 6 other MAF sensors reading this week and know exactly what it should look like on his scanner. His scanner may show the issue and the fact that the sensor itself is not the problem.
There is no indicator that your plugs and wires are worn. Incomplete combustion is worse with load so even a good idling car can need plugs and wires. A scope is about the only way to test plugs and wires. Step one to any bad MPG job is to make sure all maintenance is up to date. Plugs wires filters then replace both primary O2 sensors. If it still not running right and the plugs have “Normal” wear on them then the car need to go on an engine analyzer. The plugs themselves can tell a mechanic what is going on at lease what was going on right before the motor was shut off.
The key to this is finding a good mechanic that works on driveablitly issues all day long.
On rare occasion bad MPG is not caused by the motor at all. It can be cause by sticking brakes or a slipping transmission.
There is no indicator that your plugs and wires are worn. Incomplete combustion is worse with load so even a good idling car can need plugs and wires. A scope is about the only way to test plugs and wires. Step one to any bad MPG job is to make sure all maintenance is up to date. Plugs wires filters then replace both primary O2 sensors. If it still not running right and the plugs have “Normal” wear on them then the car need to go on an engine analyzer. The plugs themselves can tell a mechanic what is going on at lease what was going on right before the motor was shut off.
The key to this is finding a good mechanic that works on driveablitly issues all day long.
On rare occasion bad MPG is not caused by the motor at all. It can be cause by sticking brakes or a slipping transmission.
#13
07-23-2012, 06:17 AM
Before I take it to have someone check it that way.. I've noticed that my engine cooling fan is always on regardless of temperature.. On the moment I turn the car on to when I turn it off.. Someone said something about my engine temp sensor and it being faulty and not showing up on the cars comp. and causing my car to run rich.. What do u think?
Edit: If I remember right your PCM has 3 modes. Open loop (car needs to warm up) Closed loop (everything is working) and Limp Home Mode (Sensor data is out of normal parameters). The fan is turned on with Limp home mode to protect the motor. Its been over 20 years since my training but I think that was how it worked. Limp home mode can be caused by a lot of sensors.
Last edited by Gorn; 07-23-2012 at 03:41 PM.
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