It Happened All The Sudden My Truck Just Would Not Move While In Gear Runs Rough. A Neighbor Sad He Had A Ford An The Fuel Pressure Sensor Went Out . I Went A Bought One Only To No Avail, Also Put In A New Fuel Filter . Anybody Got An Idea.

 

I always start with the basics. It's either not getting air, gas or spark. Pull an injector but leave it plugged in and crank it over and see if you get gas. Pull a plug and see if you have a spark. Make sure the intake isn't restricted. Doing these 3 tests and posting your results will help us troubleshoot your problem.

 

Whatever you do, don't pull an injector to see if you are getting fuel. Just buy a $35 fuel pressure gauge at the parts store and check fuel pressure at the shrader valve on the fuel rail. Pulling the injector and turning on the key will cause the injector to shoot out of the rail and spray you and everything around you with fuel. You are dealing with up to 80 psi of fuel pressure. That's why the fuel rails are bolted down. Plus, that is way too much work to test fuel pressure. Good luck!

 

Care to share what year and engine so we know what we should refer to?
This is getting off to a crystal ball start!

 

check the air filter, if It can't get air whe it needs it, it will stumble. I had the air box to my 88 f150 get clogged a few years back out of the blue - it was a piece of cardboard that got wedged in there somehow while I was on the highway

 

This is good advice, I didn't think of the safety concerns... just the point of seeing if you have fuel. However, having fuel pressure at the shrader valve does not necessarily equate to the injectors spraying gas into the chambers.

Are you still having problems?

 

well todat i pulled of the k/n an it looked good an clean also pulled a coil to see if i was getting spark an i was, pulled the injectors and an getting fuel but dont know if the pressure is good. thank you all for the responce

 

2003 f150 5.4

 

where is the shrader valve. excuse me for being so dumb. i have changed the fuel regulator valve already

 

i did those 3 thing an still no change thank you though

 

clean the Mass air flow sensor, the most common problem for the synptom. Don't mess with the IAC. It has nothing to do with your problem. Pulling and injector and watching the fuel is a waiste of time onless you can see the correct volume come out as it spays everywhere and causes a very big safety hazard. Fuel pressure gauge hooked up to the port on the fuel rail (near firewall on the passenger side) and read the pressure while low on power. Pressure should be the same as at idle or up to ten pound higher (depend on manifold vacuum, I'd expect about 8 pounds higher than idle). you know you have fuel coming out of the injectors because it runs. If it didn't you can you a noid light to check for power and ground and/or unplug the coil and crank over and then remove a plug and see if it is wet. the computer uses default on times for the injectors on starting. Make sure you wait a little on these boards to let a few answer and could save a little time/effort. We, including myself, are not correct with best ways all the time.

 

I still disagree about the validity of pulling the injectors, however this thread isn't meant to be an avenue to prove any of my opinions, so on to the next step.

You have air, you have fuel and you have spark. That is good, now the combination of the 3 is off. I will ask an obvious question, is the check engine light on? If so, have you checked the codes? If there is no light, I would assume (we'll see if that backfires) that the problem is not a sensor. Unless the truck swallowed a small bug or bird, the MAF should be clean and functioning but it's worth a check.

My next question would be, while it's idling, does it idle smooth or really rough and appear to be missing? Is there a pinging sound? Is there any smoke coming out of the tail pipe when you give it the gas?

This can lead us to an air/fuel mixture problem, a spark problem or something else.

Did you go through any water recently?

Let us know!

 

I'm going to throw out an early guess and say it's a spark problem, after re-reading your first post and seeing the word "Rough".

Possibly a coil pack, plug wires. Make sure and remove all the boots from the spark plugs and look for any water damage, rust, deposits, etc. inside the boot, make sure all the wires are seated properly. Since it happened "Suddenly", I would investigate the coil packs though.

These are just my opinions, I could very well be wrong.



Mike

 

good idea, there could be some mornig dew type moisture in the spark plug tube misfiring a few of the cylinders or similar causing the misfire. The maf sensor is a big one in air/fuel ratio but generally doesn't happen all at once, more graduale. If you have access to fuel pressure gauge. what is it while running rough. Or remove the fuel return line from fuel pressure regulator and see if it is returning fuel. If not pump is not keeping up, would also give low pressure on gauge reading. Be very careful with open fuel near motor lots of stuff spark

 

Any update?