Mercury Repair Questions? Ask a Mechanic for Answers ASAP
The MAF sensor could defiantly cause this concern so I would try cleaning it first. Remove the sensor from the housing with a T20 torx bit and clean the sensor bulbs good with some electrical cleaner. Do not touch the sensor bulbs with your fingers. Blow them dry with some shop air or a hair dryer and reinstall. Disconnect your battery for about 30 minutes to reset the fuel strategies in the computer then test drive for about 25 miles to complete the monitors with a couple of wide open throttle burst and then see if this does not solve your concern.
It is possible for the crankshaft sensor to do this also so when it is acting up watch your check engine light. It should come on when you turn the key to the run position,go out while cranking. If it stays on when you start cranking or comes back on while cranking then your PCM is not seeing the sensor.
There is one more thing also,Ford has a calibration update for the PCM for a hard start after a 30 minute or more hot soak when running winter blend fuels. So you may need to have your local dealer reprogam the PCM. The TSB number is XXXXX
Here is a copy of it.
Some vehicles may exhibit a rough idle, or hesitation when first operated after being parked for 20-30 minutes (also known as a hot soak condition). This may be due to the presence of winter grade fuels along with the existing Powertrain Control Module (PCM) calibration. The present calibration may not increase the fuel pressure sufficiently when first started after a hot soak to compensate for the winter grade fuels. This may result in fuel vapor (instead of liquid fuel) accumulating in the fuel rail and ultimately being directed to the cylinders through the injectors.
Reprogram the PCM with a new calibration which has a revised fuel pressure strategy. Refer to the following Service Procedure for details.
Obtain an Authorized Modifications Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
Yes MAF is the mass air flow sensor. Here is a pic of it I have circled the sensor itself.
Remove the 2 torx screws and lift the sensor out of the body. There is an oring between the sensor and body so make sure not to lose it. The clean the 2 sensor bulbs with electrical cleaner and blow it dry.
had it done at auto shop said showed cam sensor and oxygen sensor what ould you think to do next the check engine light ent out after i cleaned the MAF but now it back on
Yes lets get the codes again,I am looking to see if you maybe now have missfire codes since you replaced the cam sensor?
Also which 2 cylinders seem to not fire when it acts up? Your ignition is fired in pairs,cylinders 1 and 4 are fired together and 2 and 3 are fired together.
Yeah see that doesn't make sense if it is the 1st 2 unless you have some kind of restriction in air cleaner or intake or a vacuum leak .
Of course the cam sensor is what fires the injectors(thats is its only purpose) and normally when you have a problem there the PCM will go into fault mode and fire all four at the same time. I am wondering if since you replace it if now it may be setting a miss-fire code? Would be good to know this.At this point I am trying to determine if it is fuel related or ignition causing this.
Yes you do have some very strange symptoms here. The sounding like a jet and lack of power sounds like maybe a restriction either exhaust or intake but normally this is more prevalent after engine is warmed up and not cold or wet conditions. Normally cold or wet conditions lead more to a corrosion problem in one of the electrical connections or something along those lines.
But at this point lets not leave any stone unturned. I would defiantly check for an exhaust restriction since it is not that hard on this vehicle.Go to the DPFE sensor here is a pic of it.
Unhook one of the hoses from it that go down to the exhaust and hook you a vacuum/pressure gage into it and take some readings. You are looking for 1 PSI or less at idle and 3 to 4 PSI at wide open throttle. If you have more than this then you have an exhaust restriction,most likely the catalytic converter.
Check your fuel pressure make sure you have it especially when the concern is present.