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Scott W.
Scott W., Ford Technician
Category: Ford
Satisfied Customers: 3288
Experience:  28 yrs. experience as Ford ASE Master Technician. Accolades include being a 2005 Ford PTS Regional Finalist and 2006 ASE Ford National Technician.
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2015 f550 6.8 93k miles. Runs very bad.

Customer Question

2015 f550 6.8 93k miles.
Runs very bad.
Submitted: 1 month ago.
Category: Ford
Expert:  Chad Farhat replied 1 month ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Expert:  Chad Farhat replied 1 month ago.

Hey how are you

1- DTC -P0300 : Random multiple misfire , this fault code is causing all the others fault , what we call collateral faults

most likely a vacuum leak ?

2- fuel filter changed ?

3- on cold engine ,started and spray starting fluid on the engine does the engine rpm surges up ?

4- have you checked the air filter clogged ?

HD: Misfire Detection Monitor HD: Introduction See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > HD: Misfire Detection Monitor - Introduction HD1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) Are DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309, P0310, P0313, P0315, P0316 or P1336 present? Yes - For DTC P0315, GO to HD19 . - For DTC P1336, GO to HD16 . - For all others, GO to HD2 . No - RETURN to Section 3 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > SECTION 3: Symptom Charts , Symptom Charts for further direction. HD2 VIEW THE PCM MISFIRE FREEZE FRAME DATA Note:The misfire freeze frame data may be used to determine the operating conditions when the misfire DTC was set. - Retrieve and record any available misfire freeze frame data PID values from the PCM. - Compare recorded freeze frame data PID values to the typical reference values in Section 6 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > SECTION 6: Reference Values , Reference Values. Are any values out of range? Yes - REFER to the table in Pinpoint Test Z to find corresponding circuit, and PROCEED with the intermittent diagnosis. - GO to Pinpoint Test Z See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Z: Intermittent - Introduction . No - GO to HD3 . HD3 RELATIVE COMPRESSION TEST Note:The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available. - Carry out the Relative Compression Test. Refer to the instruction manual provided by the scan tool manufacturer. Do all cylinders pass the test? Yes - GO to HD4 . No - CARRY OUT a cylinder compression test on the suspected cylinder. REFER to the Service Information Section 303-00, Engine System - General Information to diagnose the non contributing cylinder concern. HD4 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS - Retrieve the PCM continuous memory DTCs. Are there any non-misfire continuous memory DTCs present? Yes - DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Diagnostic Trouble Code (DTC) Charts and Descriptions. No - GO to HD5 . HD5 CHECK FOR ANY KOEO SELF-TEST DTCS - Carry out the PCM KOEO self-test. Are any KOEO DTCs present? Yes - DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Diagnostic Trouble Code (DTC) Charts and Descriptions. No - GO to HD6 . HD6 CHECK FOR ANY KOER DTCS - Carry out the PCM KOER self-test. Are any KOER DTCs present? Yes - DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Diagnostic Trouble Code (DTC) Charts and Descriptions. No - GO to HD7 . HD7 CYLINDER POWER BALANCE TEST Note:The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available. - Carry out the Power Balance Test. Refer to the instruction manual provided by the scan tool manufacturer. Are all cylinders contributing correctly during the power balance test? Yes - GO to HD9 . No - GO to HD8 . HD8 CHECK THE IGNITION SYSTEM FOR CONCERNS - For ignition coil on plug (COP) equipped vehicles, GO to JB4 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > JB: Secondary Ignition (COP) - Pinpoint Test and follow the pinpoint test direction. - For ignition coil pack equipped vehicles, GO to JC4 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > JC: Secondary Ignition (Coil Pack) - Pinpoint Test and follow the pinpoint test direction. Is an ignition related concern present? Yes - REPAIR as necessary. - Clear the PCM DTCs. REPEAT the self-test. No - GO to HD9 . HD9 RELATIVE INJECTOR FLOW TEST Note:The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available. - Carry out the Relative Injector Flow Test. Refer to the instruction manual provided by the scan tool manufacturer. Are all injectors flowing correctly? Yes - GO to HD10 . No - CHECK for a loose connection, and damaged or corroded terminals. REPAIR as necessary. - GO to HD10 . HD10 CHECK THE FUEL SYSTEM FOR CONCERNS - GO to Pinpoint Test HC See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > HC: Fuel Delivery System - Introduction and follow the pinpoint test direction. Is a fuel system related concern present? Yes - REPAIR as necessary. - Clear the PCM DTCs. REPEAT the self-test. No - GO to HD11 . HD11 CHECK THE VACUUM SYSTEM Note:Some vacuum leaks can be heard. - Visually inspect the vacuum hoses for signs of damage or deterioration. A collapsed vacuum hose may cause a blockage to one of the various actuators or sensors. If a blockage is found remove the blockage or install new parts as necessary. Is the vehicle vacuum system OK? Yes - For Escape/Kuga 2.5L, - Fusion 2.5L, and - Transit Connect 2.5L, GO to HD12 . - For all others, GO to HD14 . No - REPAIR the vacuum system. - Clear the PCM DTCs. REPEAT the self-test. HD12 MONITOR THE EEGR SYSTEM RELATED PIDS - Ignition ON, engine running. - Bring the engine to normal operating temperature. - Access the PCM and monitor the EGRMC1F (MODE), EGRMC2F (MODE), EGRMC3F (MODE) and EGRMC4F (MODE) PIDs. - Access the PCM and monitor the MAP (PRESS) PID. - Record the PID values with the engine idling. - Ignition ON, engine OFF. - Record the PID values with the engine off. - Compare the recorded PID values to the typical reference values in Section 6 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > SECTION 6: Reference Values , Reference Values. Are any values out of range? Yes - GO to Pinpoint Test KD See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > KD: Electric Exhaust Gas Recirculation (EEGR) System - Introduction and DIAGNOSE the EGR system. No - GO to HD13 . HD13 RECREATE THE MISFIRE SYMPTOM WITH EEGR SYSTEM DISABLED Note:The PCM may store EGR system related DTCs during this procedure. Note:To recreate the original conditions that set the DTC or caused the symptom, the vehicle may require driving. - Ignition OFF. - EEGR Assembly connector disconnected. - Access the misfire freeze frame data (if available) and record the operating conditions. - Obtain information from the customer information worksheet or any other available data from the customer. - Recreate the misfire symptom using the freeze frame and customer information. Can the symptom be recreated? Yes - GO to HD14 . No - REMOVE and INSPECT the EEGR for signs of contamination, unusual wear, carbon deposits, binding or other damage. REFER to the Service Information Section 303-08, Engine Emission Control for more EGR system information. REPAIR as necessary. - Clear the PCM DTCs. REPEAT the self-test. HD14 CHECK FOR BASE ENGINE CONCERNS Note:The engine temperature may affect the results. - This step determines if there are any base engine concerns that may have caused the misfire DTC or drive concern. - Ignition OFF. - Carry out the following tests in order to evaluate base engine integrity: - For vehicles equipped with mechanically driven cooling fans only, rotate the cooling fan by hand. The cooling fan should rotate freely, with no abnormal binding or interference. If binding or interference is present, remove any foreign materials or repair the cooling fan as necessary. - Refer to the Service Information Section 303-05, Accessory Drive and carry out checks in the Visual Inspection Chart. - Refer to the Service Information Section 303-00, Engine System and carry out the Compression Test and Cylinder Leakage Detection. - Refer to the Service Information Section 303-00, Engine System and carry out the Valve Train Analysis. - Visually inspect the positive crankcase ventilation (PCV) valve and tube for leaks. - Refer to the Service Information Section 303-00, Engine System and carry out Component Tests. Is a concern present? Yes - REPAIR as necessary. REFER to the Service Information Section 303-00, Engine System. - Clear the PCM DTCs. REPEAT the self-test. No - For DTCs P0300 or P0316, GO to HD17 . - For all others, GO to HD15 . HD15 CHECK FUEL INJECTORS Note:For vehicles without the injector disable PIDs, follow the Yes answer. - Ignition ON, engine running. - Access the PCM and control the suspect INJ_OFF (MODE) PID. - Command the suspect injector OFF. Does the engine RPM change? Yes - GO to HD17 . No - CHECK the suspect fuel injector connector and pins for damage, corrosion or an incorrect connection. If no concerns are present, INSTALL a new Suspect Fuel Injector. - Clear the PCM DTCs. REPEAT the self-test. HD16 CHECK THE CMP SENSOR - Ignition ON, engine running. - Access the PCM and monitor the SYNC (MODE) PID. Is a concern present? Yes - A CMP sensor that is installed out of synchronization may set a DTC. - To verify the correct CMP sensor installation, REFER to the Service Information Section 303-14, Electronic Engine Controls. - If the CMP sensor is installed correctly, - GO to HD17 . No - GO to HD17 . HD17 CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE Note:If the generator/regulator is electrically noisy, the noise decreases when the B+ connector is disconnected. - Ignition ON, engine running. - Monitor the generator for an audible electric noise. - Ignition OFF. - Generator/regulator B+ connector disconnected. - Ignition ON, engine running. - With the engine running, determine if the generator is still noisy. Does the noise remain constant when the B+ connector is disconnected? Yes - GO to HD18 . No - REFER to the Service Information Section 414-00, Charging System, and DIAGNOSE the generator is noisy symptom. HD18 CHECK THE CKP HARNESS FOR INTERMITTENT CONCERNS Note:Damaged CKP wires or other physical damage to the harness may cause an intermittent short in the CKP circuit. - Ignition OFF. - Visually check for damaged CKP wires or other physical damage to the CKP harness. Is a concern present? Yes - REPAIR as necessary. - Clear the PCM DTCs. REPEAT the self-test. No - GO to HD19 . HD19 CHECK THE PHYSICAL CONDITION OF THE CRANKSHAFT PULSE WHEEL Note:DTC P0315 is set when the PCM is unable to learn and correct for the mechanical variations in the crankshaft pulse wheel tooth spacing (the allowable correction tolerances are exceeded). - Inspect the crankshaft pulse wheel for damaged teeth. - Inspect the crankshaft pulse wheel for wobble. - Inspect the crank pulley for wobble. - Check for a loose crankshaft pulse wheel. - Check the CKP sensor for damage. Are the CKP sensor, crankshaft pulse wheel and the crank shaft pulley OK? Yes - GO to HD20 . No - REPAIR as necessary. REFER to the Service Information Section 303-14, Electronic Engine Controls and check for correct CKP sensor installation. RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Resetting The Keep Alive Memory (KAM). - For Edge, - F-150, - Fiesta 1.0L, - Fiesta 1.6L GTDI, - Focus, - MKC, - Mustang, and - Transit, COMPLETE the Misfire Monitor Neutral Profile Correction procedure using the scan tool. - For all others, COMPLETE the Misfire and Fuel Monitors drive cycle procedure to learn the profile. REFER to Section 2, On Board Diagnostic (OBD) Drive Cycle See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > On Board Diagnostic (OBD) Drive Cycle. - To verify the repair, RECREATE the original conditions that set the misfire DTC or caused the symptom using the freeze frame data and customer information. MONITOR the cylinder misfire data in Mode 6 - On Board Test Results and VERIFY the misfire count is below 10. - REFER to the scan tool manufacturers manual for specific information on the Mode 6 - On Board Test Results. HD20 CHECK THE RECENT VEHICLE REPAIR HISTORY Note:Misfire Profiles stored in non-volatile memory may need to be relearned if major engine work is done. - Check the recent vehicle repair history to determine if any rotational components have been replaced such as: - crankshaft - crankshaft pulley - camshaft - flexplate - flywheel - pistons or connecting rods - front end accessory drive components Does the vehicle repair history indicate any engine repairs for rotational components? Yes - For Edge, - F-150, - Fiesta 1.0L, - Fiesta 1.6L GTDI, - Focus, - MKC, - Mustang, and - Transit, COMPLETE the Misfire Monitor Neutral Profile Correction procedure USING the scan tool. - For all others, COMPLETE the Misfire and Fuel Monitors drive cycle procedure to learn the profile. REFER to Section 2, On Board Diagnostic (OBD) Drive Cycle See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > On Board Diagnostic (OBD) Drive Cycle. - To verify the repair, RECREATE the original conditions that set the misfire DTC or caused the symptom using the freeze frame data and customer information. MONITOR the cylinder misfire data in Mode 6 - On Board Test Results and VERIFY the misfire count is below 10. REFER to the scan tool manufacturers manual for specific information on the Mode 6 - On Board Test Results. No - GO to HD21 . HD21 CHECK FOR CORRECT PCM OPERATION - Disconnect all the PCM connectors. - Visually inspect for: - pushed out pins - corrosion - Connect all the PCM connectors and make sure they seat correctly. - Carry out the PCM self-test. - Verify the concern is still present. Is the concern still present? Yes - INSTALL a new PCM. REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Flash Electrically Erasable Programmable Read Only Memory (EEPROM), Programming the VID Block for a Replacement PCM. No - The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Customer: replied 1 month ago.

I spray carb cleaner no change in engine RPM. Air filter is clean.

Fuel filter is part of pump on this vehicle .

Expert:  Scott W. replied 1 month ago.

Hello my name is ***** ***** vehicles would sometimes plug one side of the catalytic convertor, try dropping the exhaust y pipe down or use a back pressure tester screwed into both sides of the o2 sensor ports.

Expert:  Scott W. replied 1 month ago.

Sometimes you can take a rubber mallet and tap on the y pipe and listen for the catalyst rattling inside letting you know its broken and bad.

Expert:  Scott W. replied 1 month ago.

Let me know what you find, thanks Scott

Customer: replied 1 month ago.

I'll do a backpressure test . give me about 1.5 hour because I have to go for a few. I should have that done by 1.30 thanks

What are the reading for the throttle position volts #1 and #2 should be?

Expert:  Scott W. replied 1 month ago.

Here is the TP chart, find your vehicle and check the readings.

Customer: replied 1 month ago.

That chart only open half way so the f550 was not opened.

Expert:  Scott W. replied 1 month ago.

Try this,

Customer: replied 1 month ago.

Thanks It's ok. Back pressure is ok.

I have to leave but if you are on tomorrow I may message you. Thanks

Expert:  Scott W. replied 1 month ago.

Have you pulled the spark plugs and checked the coils for good spark? Also if they check out ok, you may have a loss of compresion or a cam follower that fell off.

Expert:  Scott W. replied 1 month ago.

We have also seen quite a few bad camshafts and roller followers on these 6.8's.

Customer: replied 1 month ago.

hi Scott. I put plugs and boots in to start with. (just to see if it would fix the problem and it was close to time 93k)

While it has codes for 4,6 8 and now 9 misfires the scanner show all cylinders misfiring bad. Fuel trim that is positive means the engine is running lean is this correct? That fuel trim is acting weird. It will be +20-25 at idle and the idle drops and it goes to 0 (stft) all while it is missing (I would have thought the truck would have started to run better)

Expert:  Scott W. replied 1 month ago.

I would do a compression test to rule out a base engine concern. With this many cylinders showing misfire, I suspect a timing or compression problem, maybe a coil spring broken allowing compression to travel backwards in the intake disrupting airflow. When the trim are plus 20, that means the PCM is adding 20 more fuel, minus 20 means PCM is taking away 20 percent fuel.

Customer: replied 1 month ago.

so positive fuel trim is the vehicle is running lean

negative vehicle running rich?

Expert:  Scott W. replied 1 month ago.

Correct, and you have to remember, if the cylinders are a dead misfire, the oxygen that is in the misfiring cylinder is not burnt and pushed into the exhaust then the o2 sensors tell the PCM the fuel system is lean. So basically if the engine is misfiring and then repaired more than likely the fuel trims will reset back into the normal range. So fuel trim pids are nice, but make sure it is not misfiring, if it is, the trims will be all over the place. Ford doesn't like us looking at fuel trims because they are afraid we will misdiagnose a driveability concern.