Have Ford Questions? Ask a Mechanic for Answers ASAP
Hello, when this happens is it on cold start or hot restart?
Unsure on that one right off, I will opt out, another expert should be along soon to help
Hello, sound slike you may have a fuel injector leaking down into the cylinder and causing a misfire until the excess fuel in the cylinder(s) burn off. You would have to install a fuel pressure gauge and check for proper fuel pressure and see if it leakd down after sitting for a short period of time, if so, you would have to pull the spark plugs to see which one(s) are wet with fuel and replace the affected injectors if not all 8 if you opted to do so.
That would be if you had a coolant leak and the engine was overheating it would put it in a failsafe mode but cancelling injectors as it runs so the compressed air in the cylinders would help cool the engine down
Lots of thing can put it in limp mode and it wouldnt affect it at idle. Only while driving, the check engine light would be on and store a code when in limp mode as well as store freeze frame data to know why it is in limp mode. These are known for fuel injector issues. I would concentrate on what you can verify by testing verses what if's.
Usually when sitting for a period of time and depending on how much it leaks down if it does.
Yes close to 60 psi key on engine off and hold steady not bleed down. Important to do this test when the concern occurs as well.
Ok so then at this time the injectors look to be ok. Does it happen now with the gauge hooked up the hard start/running rough? No codes are stored and it passes a Key On Engine Off & Key On Engine Running test with a scan tool?
Does the vehicle sit for long periods of time/fuel quality?
I thought you said it had no leakdown?
Ok thats normal to see after a period of time, main thing is not a sudden leak down/continual leak.
Check mode 6 data with the scan tool to identify a msfire that isnt triggering a diagnostic trouble code to know what cylinder(s) may be affected. Possible ignition coil issue, oil in spark plug tube from a leaking valve cover gasket.Causing the coil to short or misfire at times when hot on restart.
Thats the only other common issue, leaking injectors and an oil leak from the valve covers into the spark plug tubes which would require replacement of the valve cover gaskets and any coils that are contaminated. Inspect spark plug gap and wear and replace if needed
Hello, do you need more help of this concern?
Ok did the old spark plugs look worn? Only other thing to check for a random misfire is OBDII Mode 6 data which tells you what cylinder if any shows a misfire below the threshold of setting a check engine light 0-20 %
No problem, thats the only thing left to test, you would need a higher end scan tool to look at mode 6 data
If I was helpful please remember to leave a positive rating