Taylor5.4

Please help!
I'm a new forum member in great need of help. I have a 1999 f150 5.4 automatic 2wd, I've had a stalling issue and surging idle issue. Sometimes while in park, but majority of ye time when I shift into drive, wil idle fine and then rev up by itself to maybe 1100 or so and then drop back down to about 750.
It also had hesitation upon acceleration which sounds like it was bogging out due to lack of fuel, not sure. This also contributes to the stalling, which happens EVERY DAY, mainly when it is warm out. Runs OKAY at night.
I have replaced so far, the fuel pump, fuel filter, idle air control valve, crankshaft position sensor, new EGR solenoid, all new plugs, and cleaned and removed the intake and throttle body, have also cleaned the DPFE sensor. In so confused and flustered, the issues persist after all of the time and money put in and I'm finally asking for help. So PLEASE, anybody experiencing the same issues or anybody who has delt with similar ones please give me some pointers on things I may be overlooking!

Marc D

Try cleaning the Mass Airflow Sensor (MAF) This directly controls the fuel/air mixture and tells the computer when to lean/richen the mix. Use only MAF cleaner and never touch it with anything, hands,tools,cotton swabs ect. BTW the motor is supposed to surge up and down when it is cold. 750 to 1200 rpm is normal. Once it's warm it should only do it with the A/C on.

Taylor5.4

I will try the MAF cleaner, I tried carb cleaner because it was the only thing I had handy, not sure if that message it up or not. No CEL though.
It idles while cold around 900pretty smooth, but when warm at running temp, holds at 700 for about 2 seconds then slowly drops to 600 and hesitates or stalls after acceleration

Taylor5.4

To anyone who has any similar issues, look into the fuel pressure regulator, I replaced this part for about $45 and fixed my stalling/surging issue Finally!!!
So look into your fuel pressure regulator of you have any similar symptoms, I replaced many different parts and still had the issue until I replaced the FPR and it feels amazing to have my trucks reliability back. Good luck to all! -Zack

Lariat0216

I'm just wandering cause I'm having pretty much the exact same issue. Did it sound normal when idling funny? When mine is acting up which is everyday it almost sounds like a Deisel!!

Taylor5.4

Yes my truck sounded fine while idling, if you're truck does not sound like it is idling correct you should look into checking the sensors like the crankshaft position sensor and camshaft position sensor, because the crankshaft position sensor as well as the cam position sensor both have something to do with telling the fuel injectors when to fire. Check those, check EGR, check your fuel filter and fuel pump.
All of your spark plugs are good, right? Because if you have a misfire it will cause it to run funny and it won't sound right.