My 93 bronco idles around 500 rpms but only dies when i turn it sharply i replaced tps sensor and then scanned for codes i got an high voltage error but as it wormed the code went away. I sprayed wd 40 on the vacuum lines checking for leaks but there was none.
idles low
- Thread starter Roadking
- Start date
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Krafty
New member
could be the idle air controller,
yo,
So, you did the KOER test with engine @ normal op temp? & what was the Code Number, if you can remember?
If not, try it
a Self Test by our pal, BroncoJoe19
do the KOEO = Key On Engine Off portion first
& Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion
Idle or Stalling Problems & Troubleshooting; The IAC is usually a cylindrical unit attached to the upper intake manifold. This unit electrically controlled by the computer, and allows air to flow into the intake at idle, bypassing the throttle plate. The extra air is accompanied by extra fuel to bring the idle up to proper speed, and when cold, allows a high idle condition. These units may become dirty, and need cleaning. Many idle and stalling issues tend to be blamed on these units. Cleaning is achieved by removing the electrical connector, and two screws holding it on. Once off of the vehicle, clean with throttle body cleaner (or a good carburetor cleaner). Continue cleaning until unit is clean, like new; reinstall unit. This is also a good time to clean the intake, and EGR ports (if applicable). Testing may be achieved by bringing the engine to operating temperature, noting the idle speed (should be within spec). Unplug the unit’s electrical connector, and the idle should drop to about 650 RPM. When the unit is reinstalled, it should return to normal idle speed. If the vehicle does not idle at proper RPM (too low), there are no vacuum leaks, and the TPS calibration is correct, than the unit is most likely faulty
Removal & Cleaning in a 93 5.8
Source: by Bobby (blue) at http://www.superford.org/registry/vehicles/detail.php?id=3982&s=17193#content
Overview & Testing; "First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I’ve had the torture of learning throughout the years: Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller •Inlet Air Bypass •Intake Air Bypass •Intake Air Control..."
Source: by Ryan M (Fireguy50) at http://fordfuelinjection.com/index.php?p=39
"...This is really easy to test. First as with all problems you should gather the trouble-codes from the computer. Follow the codes for testing and repair. If you get a code that points to a problem with the IAB start the vehicle and bring the engine up to operating temperature. Allow the engine to idle without any driver input to the throttle or pedal. Go under the hood, and disconnect the electrical connector to the IAB. If the engine begins to stubble or stalls the IAB is functional and does not need to be repaired. If the engine idle does not change you should remove the IAB for inspection.
The IAB can pass and still need repair, or it can fail and not need replacing. The plunger and internal spring can get clogged with dirt and oil. This will slow down the air flow and not allow the IAB to function properly. Remove the IAB and clean it. There are 2 halves to the IAB, and you can not buy just one half, but you can take it apart to clean it. But if the internal solenoid is faulty the IAB needs to be replaced..."
Waveform, Good, Scroll down; "...This is a typically good ford idle air control (IAC) motor waveform. The Ford IAC waveform has its own unique "sawtooth" signature. The IAC valve is being pulsed and the duty cycle determines the volume of air through the valve. A 100% duty cycle is fully open and a 0% duty cycle is fully closed. When checking this solenoid look for dropouts or spikes in the waveform that could indicate a problem..."
Source: by omitec.com @ http://www.omitec.com/en/support/waveforms/
So, you did the KOER test with engine @ normal op temp? & what was the Code Number, if you can remember?
If not, try it
a Self Test by our pal, BroncoJoe19
do the KOEO = Key On Engine Off portion first
& Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion
Idle or Stalling Problems & Troubleshooting; The IAC is usually a cylindrical unit attached to the upper intake manifold. This unit electrically controlled by the computer, and allows air to flow into the intake at idle, bypassing the throttle plate. The extra air is accompanied by extra fuel to bring the idle up to proper speed, and when cold, allows a high idle condition. These units may become dirty, and need cleaning. Many idle and stalling issues tend to be blamed on these units. Cleaning is achieved by removing the electrical connector, and two screws holding it on. Once off of the vehicle, clean with throttle body cleaner (or a good carburetor cleaner). Continue cleaning until unit is clean, like new; reinstall unit. This is also a good time to clean the intake, and EGR ports (if applicable). Testing may be achieved by bringing the engine to operating temperature, noting the idle speed (should be within spec). Unplug the unit’s electrical connector, and the idle should drop to about 650 RPM. When the unit is reinstalled, it should return to normal idle speed. If the vehicle does not idle at proper RPM (too low), there are no vacuum leaks, and the TPS calibration is correct, than the unit is most likely faulty
Removal & Cleaning in a 93 5.8
Source: by Bobby (blue) at http://www.superford.org/registry/vehicles/detail.php?id=3982&s=17193#content
Overview & Testing; "First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I’ve had the torture of learning throughout the years: Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller •Inlet Air Bypass •Intake Air Bypass •Intake Air Control..."
Source: by Ryan M (Fireguy50) at http://fordfuelinjection.com/index.php?p=39
"...This is really easy to test. First as with all problems you should gather the trouble-codes from the computer. Follow the codes for testing and repair. If you get a code that points to a problem with the IAB start the vehicle and bring the engine up to operating temperature. Allow the engine to idle without any driver input to the throttle or pedal. Go under the hood, and disconnect the electrical connector to the IAB. If the engine begins to stubble or stalls the IAB is functional and does not need to be repaired. If the engine idle does not change you should remove the IAB for inspection.
The IAB can pass and still need repair, or it can fail and not need replacing. The plunger and internal spring can get clogged with dirt and oil. This will slow down the air flow and not allow the IAB to function properly. Remove the IAB and clean it. There are 2 halves to the IAB, and you can not buy just one half, but you can take it apart to clean it. But if the internal solenoid is faulty the IAB needs to be replaced..."
Waveform, Good, Scroll down; "...This is a typically good ford idle air control (IAC) motor waveform. The Ford IAC waveform has its own unique "sawtooth" signature. The IAC valve is being pulsed and the duty cycle determines the volume of air through the valve. A 100% duty cycle is fully open and a 0% duty cycle is fully closed. When checking this solenoid look for dropouts or spikes in the waveform that could indicate a problem..."
Source: by omitec.com @ http://www.omitec.com/en/support/waveforms/
I replaced the EGR Valve and cleaned the intake and now it idles at 1000 and doesnt die any more 
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/emoticons/[email protected] 2x" width="20" height="20" />
