yo Red Fox,
WELCOME!
I'm coming, Elizabeth!
ok, can you recall the Code number?
If not try Try a
Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.
Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.
Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.
Do Key On Engine Off (KOEO) portion first.
Look Codes up in my broncolinks.com site using the new Search function.
And Post em here according to:
KOEO
&
KOER
--
Some possible codes as a guess;
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..."
DTC 31 "...This code could be caused by several different factors. If the pintle position sensor (Ford calls it the EVP sensor) is shorted or open, you could have a code set. If the EGR valve becomes carboned up and does not seat fully, the EVP sensor gives a high reading and a code is set. If the diaphragm of the EGR valve is bad, then it, too, is flagged..."
DTC 32 or 326; "...DTC 32/326 typically means that the EGR valve is not fully seated. This can be due to a bad EGR valve, vacuum trapped in the EGR hose, a clogged EVR filter, or a bad EVR solenoid. It is also important to note that if you have an exhaust ventilation system hooked up, that this can also cause an inaccurate reading. Try disconnecting the system and retesting..."
DTC 32/328 "...in Key On Engine Off (KOEO) and Key On Engine Running (KOER) indicates that the EGR valve and/or EVP sensor voltage is lower than normal in the closed position. The EVP voltage is less than the closed limit voltage of 0.24 volts. Because of the preload of the EVP sensor it is very difficult to determine whether the EGR valve has malfunctioned or the EVP sensor has an abnormally high resistance. Possible causes: Poor continuity in EVP sensor harness or connectors. Damaged EGR valve. Damaged EVP sensor. Damaged Powertrain Control Module (PCM). Key off. Disconnect EVP sensor. Inspect the connectors at harness and sensor for damaged pins, corrosion, loose wires, etc. Service as necessary. Remove vacuum line from EGR valve. Exercise EGR valve by applying and releasing vacuum with a vacuum pump. Reconnect vacuum line to EGR valve and electrical connector to EVP sensor. Rerun Key On Engine Off (KOEO) and Key On Engine Running (KOER) Self-Test. Is DTC 32 or 328 still present? Yes - GO to DN26. No - The original DTC 32/328 was the result of poor continuity at the EVP sensor connector or binding of the EGR valve stem by contaminants. Testing complete..."
DTC 33 & 34 "...DTC 33 is triggered when the EVP sensor is not closing.... To prevent the EGR valve from opening when the engine is cold, the vacuum line to the EGR valve may be connected to a parted vacuum switch or a computer-controlled solenoid. Vacuum is not allowed to pass to the valve until the engine is warm. EGR isn't needed when the engine is cold, only when it is warm and under load. Any of these codes could indicate a faulty EGR valve as well. as well as a problem in the ...vacuum solenoids' Miesk5 note; TAB & TAD; so repair those vac lines 1st..."
DTC 33 is triggered when the EVP sensor is not closing; so EZiest & cheapest checks are to inspect & repair/replace repair any bad vac lines. for a <$ vac line test; I pull em off and use the straw sucking test; one finger over one end.
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.
Source: by miesk5 at Ford Bronco Zone Forums
see my EGR Section in my site @
http://www.broncolinks.com/index.php?index=415
I may not be back here this weekend; have to replace strg gear box and .... get some sun,
Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.
http://broncograveyard.com
GL!
