I have a 2000 F150 V-8 5.4L It is a 4X4 extended cab Short bed. 115,000 mi.

History: About 2 years ago I started getting a rough running engine under load The engine light would go on then off. So I changed the fuel filter.
This did not help.

So I bought a code reader and found it was a multiple cylinder misfire. I change the plugs and it ran ok for a couple of days. The same problem existed but there was no codes. I thought if there was a problem with the engine than surely I would get a code. I began to think it was a tranny problem so I read all sorts of horror stories about flushing transmissions and problems after. So I dropped the the pan and the pan was spotless inside. I then added new fluid and then had the tranny flushed at the Ford dealership a week later.

I still had the problem missing under load. I did not want to replace all the COPS due to cost so I ran it hard trying to draw a code to see which Cylinder was the problem. Finally it came up at the 5 cylinder. I changed out the COP and the problem was back a week later. I thought it would be cracked boots so I put the dielectric grease inside the boots to help them seal. This did not do the trick so I then bought a set of boots for all the COPS and have not had a chance to install them yet.

I then started experiencing the engine engine shutting off. The engine would start to race like it was out of gear the guages would go crazy and the engine would shut down. I would put it in N while coasting and restart the engine and be on my merry way. But still I would have the missfire symptoms.

The Truck is garaged in another state and I get to it about every 2 weeks. On one trip I found that it wouldn't start. Cranked but no start. I then figured it was the fuel pump and removed the small test valve on the fuel rail hooked up a hose to see if the pump was working. I seemed to be working because everytime I turned the key to on fuel would come out of the hose for a little bit then stop. I figured this was probably normal as if you lost pressure the fuel would probably have some sort of relay shut down. I then put everything back together and the truck fired right up.

Still I have the problems of misfire symptoms no light or codes. About a month ago I ran the truck and it ran pretty good, little bit of misfire no shut downs.

2 weeks ago the truck ran like ***** and shut down and I couldn't get it started. I had it towed 2 hours later still no start , when the truck got to the shop it started up. The mechanic read the codes and it read security issue. He said he could not legally work on a security issue and he would have to have the ford garage work on it if it happened again.

This is not my primary vehicle due to it's unreliablity and he has not checked it out since.

The only other issue I have with the vehicle is a leaking exhaust manifold.

Can anyone help me to advise the mechanic where to start looking for problems.

Can it be a key problem? I have 2 keys problems with both.

Fuel Pump issue. Isn't there a code for this.

Crank position sensor?

Misfire??

The code reader I bought is an ACTRON and it cost over $300 so I think it would be a decent one. It reads realtime diagnostics but I don't realy know what to look for.

I have a technician type job and am not a complete idiot and can fix most things if I know what to look for. Engines are not my thing since they started running computers.

Please Help.
Thanks

 

Sounds to me like the safety fuel shut off switch is malfunctioning. My only other thought is the PCM is fualty.

 

Sounds more like the PCM to me. Why else would it come up as a security issue? That's how Ford makes their money... anything electronic goes majorly wrong, they put that damn security code in there and it has to go to a Ford dealer to fix. And then you pay for it. *******s.