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running rich

  • Thread starter Thread starter sdrt
  • Start date Start date Jul 5, 2009
S

sdrt

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Mar 1, 2009
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Jul 5, 2009
#1
  • Jul 5, 2009
  • #1
i have a 93 lx and i think it is running rich. after warm up it feels sluggish when i floor it and i can smell it in the exhaust. do i start with the tps or the mass air. i don't want to do 2 things at once. i have had much help on this site so far as i am not a car guy. so thanks in advance
 

AnthonyR23

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Jul 6, 2009
#2
  • Jul 6, 2009
  • #2
Honestly, that's kinda a hard question. Do you have any error codes, or do you know how to check error codes?
 

AnthonyR23

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Jul 6, 2009
#3
  • Jul 6, 2009
  • #3
Being able to check the error codes would point you in the right direction, if you type in google ford trouble codes, the second link odb & odb2 trouble codes, there is a list of trouble codes. So if you could check your codes it would help. Then at least you would know where to look, eg. TPS or Mass Air, or O2 sensors.
 
S

sdrt

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Jul 6, 2009
#4
  • Jul 6, 2009
  • #4
i am sorry i should have explained more,i did do a koeo test with the code reader i got from summit racing. i got an 11 first which means no immediate codes right ,then in memory was a code 66 and 34. i ran the car for a day then just a 66 came up.it has a e-cam and 75mm throttle body on it, and i'm sure the kid i bought it from never had anything calibrated.
 

jrichker

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Jul 6, 2009
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Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.

If you have a K&N flat panel filter or other filter that requires oiling, excess oil may coat the MAF sensor element and cause problems.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

Changes in RPM causes the airflow to increase or decease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow. Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.

At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF wiring connector and ground. Make your measurement with the MAF disconnected from the wiring harness.


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring Mustang FAQ - Engine Information

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
 
S

sdrt

New Member
Mar 1, 2009
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Jul 6, 2009
#6
  • Jul 6, 2009
  • #6
thanks we'll try it on the weekend.
 
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