2001 S.Crew 5.4L 71,856ish miles. Bought in February.

Last week my truck started getting rough to start, seems like its starving for fuel. I didn't test with gauges but was getting fuel to the rail and can hear the pump kicking on in the tank. I took it to Autozone and there were no codes and the battery, starter and alternator "tested fine." I did reset, or at least I think I did, the switch located under the kick panel Thursday or Friday and it ran fine up until I left work for lunch today.

There is approx. half a tank of fuel in it, 160 miles into this tank which is a little lower than normal for me. Last tank I used some fuel system cleaner though. I'm not sure how recently the cops or plugs were changed if at all. The fuel filter was changed with in the last 1000 miles, I honestly can't remember the brand, but was thinking I should try a new one. We did get a bunch of rain before it started happening, central Texas guys know what I'm talking about.

The principles are all the same but these are wired differently than the diesels I'm used to. Not really sure where exactly to check next but would really like to avoid dropping the tank

 

You hav'nt ided anything so it's hard to do anything but begin to eliminate causes.
Is the gas contaminated?
Is there moisture in the plug wells from the rain?
What is the fuel rail pressure?
Crank sensor, cam sensor plugups good?
What happens after it starts and come up to operating temperature etc.
Have you used a alky water eliminator in the gas and given it enough time to absorb/combine with water.
Water settles to the bottom of the tanks and is easy for the pump to pick up.
Good luck.

 

Thanks for the starting points.

When I left this morning it started up with no problems, I drove maybe ten miles and shut it off to pick up a couple guys on the way to work. It took two tries to get it started, once I got to work it sat for a couple hours before I had to leave again and it started up no problem. As far as once it starts, I'm not noticing any excessive stuttering or any vibrations. I keep getting told its the fuel pump going out but don't want to go that route unless absolutely necessary. I'm going to pick up some water eliminator as suggested and a new fuel filter this morning.

As for the pressure at the rail, is this something I could get the gauges loaned from a parts store?

I checked the Crank Sensor this morning before leaving the house, the connector looked to be intact and securely seated. Same thing with the Cam Sensor.

Last night I pulled the front most COP on the passenger side and didn't see any signs of moisture build up, looked clean for the most part. I'm not sure on how long they've been in there, assuming that they are the factory ones. The one I pulled had a green motor craft sticker on it still.

I'll go with what I've got now to work with, thanks again.

 

My truck does this from time to time as well. Maybe once a week. Takes for ever to start. I'm beginning to think it is a bad pats key.

 

Could this be a possible cause, I haven't ran out and checked yet but to the best of my knowledge my Theft light isn't flashing when I turn the key to run and wait for everything to cycle. Personally I only have one key for the truck, guess I should have raised a bigger stink about it at the dealership, but I was tired of dealing with them after getting the rear window fixed.

According to Post #2 in this thread.
Is that something else to look into?

 

I noticed a clue in your reply of difficult hot restart.
Do the following next time is does not start right up.
Hold the throttle open about 1/4 th to give more air.
If this should help, the IAC is suspect.
Next, hold the throttle wide open to see if that causes it to fire up a bit faster.
If so, it is an indication of flooding from an injector or leaky fuel regulator diaphram.
What you do by holding wide open is shut off the injection. This is a normal action built into the program. The PCM know what to do because it sees the TPS fully open without the motor running, as a signal to shut off fuel injection.
Good luck.

 

Ill give that a shot when I leave to go home thanks. I saw in another thread someone suggested cleaning the IAC, which I was planning to do tonight, with carb cleaner.

 

Very helpful info. And come to think of it, it only happens when my truck is warmed up.

 

replace the plugs/plug wires.

 

I tried what you said with the TPS, nothing. After talking to another guy at work that's smarter with this stuff and has a better ear than me suggested checking for spark. We jumped the cam and crank sensors with a jumper wire, with no change. Again pulled the front most pack on the passenger side to see if there was anything there, nadda.

Looks like I chased my tail for two days on the fuel system. Time to look at the electrical side, or should I just go ahead and change the COPs and plug (keep in mind the 71800+miles)? Considering what I went through the dealership with other stuff I wouldn't be surprised if they didn't change the plugs.

Bluegrass I appreciate all the help.

 

Not to get off track but tell your friend he cannot jumper sensors like these and expect a good result on Fords because they must send pulsing signals to the computer.
If they are jumpered, no pulsing can take place and no good results can be obtained. The PCM would see the jumpers as a shorted sensor and a fault.
At this point I don't know anything else that you could check out easy.
At this point I would be using my scanner to look at the operating PIDs in the program for any that are out of limits.
To do this you would have to invest in a good scanner, not a reader that will look at program information.
Then you would need the program information to be able to spot displayed parameters that are out of limits.
.
Back to your issue; when cold starting, the PCM looks at the coolant sensor for a cold value to set the fueling richness.
As the engine warms, the OX sensors take over fuel control.
Note that the OX sensors even if open would not prevent the motor from hot starting because the PCM will go to a fixed table to fuel the motor and set a code indicating the OX sensors are out of order. That would be to easy.
On hot restart, the OX sensors are too cold to work at start time so the PCM has to look at the coolant sensor again for guidence on fueliing. It's now very much warmer from the coolant that has not had time to fully cool down.
Maybe something is going on with the coolant sensor or it's plugup.
Here is where a scanner would be able to look at it's operation as well as others for a lead on the issue.
.
A dealer tech is supposed to be trained to work with a scanner to detect issues AND use logic and knowledge to solve the problem. This is the true meaning of the title of Technition and not just a parts changer or just following a brick road and give up if the problem is not found.
Best I can offer for the moment.
Your at a point, that lacking infomation and capability puts you at a great disadvantage unless someone can apply the above methods to see the issue or some luck occurrs for you.
Good luck.

 

Thanks again Bluegrass. I understand what you mean by throwing parts at until it works.

Time to do some more research before I turn it over to a tech.

 

One of the first things you do, -if not the first, is rule out a fuel problem. IMO it could be the pump or anything in conjuction,-directly. You have to check you rail pressure per instance. A failing/lazy pump may be on it's way out.

Also, touch/feel your pump relay when this happens. If it's hot to the touch, -most cases it's bad.

Also, Operating temp/Crank no starts can be a regulator issue. Test the reg when monitoring pump pressure. You'll have purchase a cheap pressure gauge to monitor this way.

Rule out the fuel system, - go from there. There's no DTC's on the KAM right ? That right there is a clue. Fuel problems don't usually produce DTC's, unless your misfiring. So, unless a better clue presents itself, I'd get that out of the way first. Sucks being stranded.



Good Luck.

 

Thanks Jbrew.

When I went back this morning tried it again, got it started with a little help from carb cleaner which leads me to thinking chasing a spark issue isnt needed.

(phone posting sucks)

 

You did say you tried cleaning the IAC out? Do the throttle body and MAF sensor too if already not done. This sounds too much like the IAC to me. How's the battery by the way?