yo J,
I have to go out; may not be home for awhile today; then I'll look up the codes and post; for now
*** EDIT; HERE ARE THE CODES ***
Do you detect an aroma of burnt electronic components where PCM is in drive kick panel?
DTC 22 indicates the Manifold Absolute Pressure (MAP) sensor is out of Self-Test range. Correct MAP range of measurement is typically from 1.4 to 1.6 volts.
Do NOT use an ordinary voltmeter to check a Ford MAP sensor because doing so can damage the electronics inside the sensor. This type of sensor can only be diagnosed with a DVOM that displays frequency, or a scope or scan tool
Also make sure engine manifold vacuum is within specifications at idle. If vacuum is unusually low due to a vacuum leak, ******** ignition timing, an exhaust restriction (clogged converter), or an EGR leak (EGR valve not closing at idle).
A low intake vacuum reading or excessive backpressure in the exhaust system can trick the MAP sensor into indicating there is a load on the engine. This may result in a rich fuel condition.
A restriction in the air intake (such as a plugged air filter), on the other hand, may produce higher than normal vacuum readings. This would result in a load low indication from the MAP sensor and possibly a lean fuel condition.
A good MAP sensor should read barometric air pressure when the key is turned on before the engine starts. This value can be read on a scan tool and should be compared to the actual barometric pressure reading to see if they match. Your local weather channel or website should be able to tell you the current barometric pressure reading.
Check the sensor's vacuum hose for kinks or leaks. Then use a hand-held vacuum pump to check the sensor itself for leaks. The sensor should hold vacuum. Any leakage calls for replacement.
An outright failure of the MAP sensor, loss of the sensor signal due to a wiring problem, or a sensor signal that is outside the normal voltage or frequency range will usually set a diagnostic trouble code (DTC) and turn on the Check Engine light
and;
"...The vacuum gauge should show 18-22 in-Hg @ idle, and maintain a steady needle. Rev it up to ~2500 rpm, hold it steady, and you should see the needle drop, then slowly increase to a level close to the idle reading (though slightly lower is normal)..."
Source: by SigEpBlue (Steve)
Possible causes:
circuit open between sensor vehicle harness connector and PCM.
circuit shorted to VREF, SIG RTN, or GND.
Damaged MAP sensor.
Vacuum trapped at MAP/BARO sensor.
Unusually high/low barometric pressure.
Kinked or obstructed vacuum lines (MAP).
Basic engine (valves, vacuum leaks, timing, EGR valve, etc.).
High atmospheric pressure.
Damaged PCM.
VREF circuit open at MAP sensor.
SIG RTN circuit open at MAP sensor.
The pinpoint test directs you to check the voltage to the MAP sensor. With the MAP sensor connected, use paper clips to back probe the MAP connector so you make contact with the terminals inside the connector by inserting the paper clips into the bak of the connector. This allows you to get voltage readings while the connector is plugged in. The other option is to use straight pins to pierce the insulation of the wires. First check the voltage of the outer two wires of the MAP connector by connecting a voltmeter to the clips or pins you have inserted. You should see 5 volts with the key on. This is the power to the sensor.
The BLK/WHT wire provides a ground called Signal Return (SIG RTN on EEC), it will show 0 volts with the black probe on negative battery terminal. The 5 volts VREF (ON EEC) (Reference Voltage) is supplied on the ORG/White wire. The Signal the computer reads is on the middle wire, DK GRN/Lt Green (MAP on EEC). The correct MAP/BARO range of measurement is typically from 1.4 to 1.6 volts on the Signal (middle wire).
More Diagrams & Technical Service Bulletins @
http://www.revbase.com/BBBMOTOR/Wd
If any of the voltages are out of range, there is a wiring problem that needs to be tracked down and repaired. These three wires all go back to the computer. The signal wire (middle) is the only one not shared by other sensors, it goes straight to the computer. The Signal Return and VREF are also provided to other sensors
see my Vacuum Leak Test; @
http://broncozone.com/topic/23994-90-58l-getting-continuous-code-33-and-running-code-44/
86 Bronco Wring Diagrams
MAP, etc @
http://www.revbase.com/BBBMOTOR/Wd/DownloadPdf?id=27262
DTC 72 indicates that the MAP sensor output did not change enough during the Dynamic Response Test.
Possible causes:
-- System failed to detect partial WOT.
-- MAP sensor vacuum supply hose improper routing, blockage and/or linkage.
-- Damaged MAP sensor.
l Rerun Engine Running Self-Test. Be sure a complete WOT is performed during the Dynamic Response portion of the test by RLA
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83 in Key On Engine Off, or Continues Memory
Low speed fuel pump relay circuit open.
See the wiring diagrams are in the above site or use;
Wiring Diagram in an 86
Source: by Xris at
http://www.supermotors.net/registry/media/648663_1
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DTC 16 IDM signal not received. the signal from the ignition module was not received by the ECA for Self Test; most common cause would be a bad ignition module
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DTC 31 "...in most case is set due to a bad EVP (EGR position sensor) mounted on top of the EGR valve. Check the voltage of the EGR Valve Position (EVP) sensor on the Brown/Light Green (BR/LG) wire with the key on, engine off. Normal closed valve voltage will indicate 0.35-0.50 volts. When the EGR valve is opened with a hand-held vacuum pump, the sensor voltage should increase. If the EVP voltage is incorrect and it does not move when the valve is opened, verify that the Brown/White (BR/W) wire indicates 5.0 volts and the Grey/Red (GY/R) wire is a good ground to the sensor. If the EVP sensor voltage is out of range with the valve closed but increases when the EGR valve is opened, adjust the EVP sensor voltage so that it indicates 0.40 volts with the valve closed. Once the code 31 is resolved with the EVP sensor voltage, monitor the O2 sensor operation when the vehicle is driven to determine that the pinging condition and buck/**** symptom is a result of lean running. Check Manifold Absolute Pressure (MAP) sensor Hz. A normal Key On Engine Off (KOEO) reading will indicate 156-159 Hz at sea level elevations. Verify fuel pressure is good. Fuel pressure should be 30-33 PSI at idle and increase to 40 PSI when brake-torquing the engine. Check base ignition timing to verify it is at 10 degrees BTDC. Check ignition timing with the Spark Output (SPOUT) connected. Timing should be 20-25 degrees BTDC at idle. If timing advance is low, check the harmonic balancer for slippage..."
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DTC 12 can't control engine RPM high RPM self test; vacuum leak, base idle off, idle air valve dirty or bad, EGR stuck open. Check the IAC valve port in TB for Sludge; Suspect throttle body coking.
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DTC 41 System lean – Fuel control/ 41
HEGO sensor circuit indicates system lean (right side) for cont memory code 41
No HEGO switching detected always lean (right side - BANK 1) for KOER
also;
DTC 41, 42, 91, 92, 136, 137,139, 144, 171, 172, 175, 176, 177 & some Possible Causes for Rich & Lean HEGO; "...The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test. To accomplish this, the engine should be at normal operating temperature.."
Source: by Ryan M (Fireguy50)
DTC 41, 42, 85 OR THREE DIGIT CODES 171, 172, 173, 179, 181, 182, 183 & 565 are received, Check for proper HEGO Ground;
in No power - exhaust restriction 86-91 E (91-12-11)for 86-91 Bronco, F Series, & Econoline (Catalytic Converter Diagnosis)
Lack of power or a no start condition may be diagnosed as an exhaust restriction caused by a plugged catalytic converter. A plugged catalytic converter (internal deterioration) is usually caused by abnormal engine operation.
Diagnose the catalytic converter to confirm internal failure. Refer to the Catalyst and Exhaust System Diagnostic Section, in the Engine/Emissions Diagnostic Shop Manual and the following procedures for service details.
Lack of proper HEGO operation may cause, or be the result of a rich or lean fuel condition, which could cause additional heat in the catalyst. Perform self test KOEO and KOER, service any codes.
NOTE: IF TWO DIGIT CODES 41, 42, 85 OR THREE DIGIT CODES 171, 172, 173, 179, 181, 182, 183 AND 565 ARE RECIEVED, CHECK FOR PROPER HEGO GROUND.
the HEGO ground is good, the following areas may be at fault:
Ignition Coil
Distributor Cap & Rotor
Bad or disconnected Spark Plug Wires
Fouled Spark Plug(s)
Dirty Air Filter
Stuck Open Injector
Fuel Contamination & Dirty Engine OIL
Intake Manifold Leaks
Exhaust Leaks
Fuel Pressure
Poor Power Ground
Engine Not At Normal Operating Temperature
BAD HEGO Sensor
Spark timing that is ******** from specification may increase exhaust gas temperature and shorten catalyst life. Refer to the following procedure for service details.
Check spark timing. Check base timing with SPOUT disconnected. Set base timing to the specification on the vehicle emission decal. See my site for timing
& note this;
Timing Procedure Manual Update TSB 90-18B-2 for 84-90 Bronco F Series, Econoline, Ranger & 86-90 Aerostar; May Exhibit Spark Knock/Ping after Starting Engine w/Remote Starter; Start Wire S Terminal Disconnected at Starter Relay with the Key On Will Cause the TFI-IV ICM to Revert to Start Mode Timing after the vehicle is started (Timing Will Be ********). Ignition Timing will be Incorrectly Advanced if Base Timing is Set while the Module is in Start Mode. Engine must be started w/the Start wire connected, using ignition switch to correctly set the base timing.
Source: by GENCO
read more @
http://broncozone.com/topic/23155-89-bronco-hesitation-and-power-loss/
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DTC 34 EVP circuit has intermittently failed above the closed limit of 0.67 volts.
DTC 34 - EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the ****** side of the EGR by mouth. the egr is not closing properly which can cause detonation. remove the egr and clean off any carbon built up on it with carb cleaner and a brush if necessary.
DTC 34 "...in Key On Engine Off (KOEO) or Engine Running (KOER) Self-Test indicates that the EGR valve and/or EGR Valve Position (EVP) sensor may not be fully seated in the closed position. The EVP sensor voltage is greater than the closed limit voltage of 0.67 volt. Because of the preload on the installed EVP sensor, it is very difficult to determine whether the EGR valve is seated or the EVP sensor is in contact with the EGR valve stem..."
Source: by rla2005 (Randy) via miesk5 at
http://broncozone.com/topic/22091-throttle-position-sensor-trouble/
DTC 34; Next isn't listed by anyone for the 34 Code, but is a good test anyway to rule the EVR out & is a simple multimeter test; The EGR Vacuum Regulator (EVR) controls the opening and closing of the EGR valve. The EVR is an electromagnetic solenoid and should have between 20-70 ohms resistance between the pins. +12volts should be constant on one side from the EEC Relay, the computer controls the ground signal when EGR flow is needed. When the EGR Vacuum Regulator (EVR) is off, both ports vent slowly to atsmophere. To test it mechanically check to see if vacuum is present at the EGR valve with the electrical connector unplugged from the EVR. The top port should not have vacuum! Because that would open the EGR at the wrong times. With everything connected and the engine running ground out the pin 33 side. The EGR vavle should open and the engine RPM should change.
Source: by miesk5 at Ford Bronco Zone Forums
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DTC 25 Knock Sensor not tested (KOER); ignore if not pinging
/emoticons/
