I have a 2001 F-150 With the 5.4 in it, Have an annoying problem. Last year (february 2004) I had a problem with the engine not starting. I would get up first thing in the AM and the truck would start fine every time. with engine warmed up I would drive approx. 10-15 miles to work to arrive at 7 AM. Everything ok. 2-3 hours later I would go out to start the truck and Have a crank But No start condition. No matter how many times I tryed No start. But as soon as I Depress gas pedel slighty Engine cranks and fires right up. No DTC's Or MIL. Had this problem for 2 months, a friend who works at a ford dealer Suggested replacing IAC (Idle air Control) replaced this in april of 2004, Problem seemed to be fixed. Drove truck all summer and all of this winter so far. bout 1 month ago (february 2005) Started same symptoms all over again. after bout 2-3 hours heat soak Engine has either a hard start or no start condition. But when I Crack open throttle it fires right up. Thought it may be IAC again So I replaced it Again and problem Still Exists. This problem Im Sure is More Annoying Than Serious But Im Running out of Ideas. Pretty Sure I hear fuel pump every time I turn key on. Does anyone Have any Suggestions or Ideas.........

 

near the iac sensor is a small canister the size of a tylenol bottle with a vented cap. take the cap off and there is a little foam filter in it and if you are in dusty or muddy conditions it clogs up. wash it out with water and then spray carb cleaner in the small vacuum port the filter fits around. this should help because i tried it on my pa in laws work truck with the same problem. he also had the iac sensor replaced. also get some good fuel treatment that seemed to help a little.

 

I would even look into the Throttle Position Sensor. If all you have to do is crack the throttle open and the truck starts right up, that would be the first thing I would look at. Just my 2 cents, for what it's worth

 

Thanks for the Ideas!!!! This is the type of problem that I wish it would just completely quit or give me a MIL or something LOL!!! Today is Saturday 3-5-05 Im gonna try looking at these Ideas!!!Thanks for the Input. Any More, or other ideas is appreciated....

 

Still Hunting For My Problem. The Temperature outside was a little warmer today.Truck had Sat for about 2.5 Hours tonight (50 Degrees outside here) When I started it , It fired up but seemed like there was a little delay from the time I cranked till the time it fired ......If that makes any sense to anyone....... Does anyone know How to test The TPS????? Please let me know !!! Keep the Ideas coming!!!! Thanks

 

With the throttle closed, key on, and engine off the TPS output voltage should be between .6 and .95 volts. As long as it isn't over 1.0 Volt. With the throttle fully opened, the voltage should rise to 4.5 to 5.0 volts. It should rise smoothly with the movement of the throttle plate with no dropouts or spikes.

Based on your symptoms and history, it sounds like a problem CONTROLLING the IAC valve. That would lead me to suspect the wiring to the IAC or even possibly the PCM itself. More troubleshooting would be suggested before deciding to replace it though.


Steve

 

I have the same problem w/ my 2001, 5.4L. Seems to go through phases.
The problem keeps getting worse, so I'm taking it to the dealer tomorrow since it's still under warranty. They probably won't be able to figure it out (idiots), but if they do, I'll post it. -Justin

 

Well, the dealer claims the mass-air sensor and throttle control sensor are bad and need to be replaced. The warranty's covering most of it, but otherwise they said it would have cost $1200. Hopefully that'll fix the problem. Good luck, -Justin.

 

Hi Justin - Weve been having the same situation as the others in this post, my question for you is after the dealer put on the new goodies did your problem go away 100%? Im really curious.
Thanks
ALR

 

Let me cure your pain guys. I had the exact problem for the last 2 years with my '01 F150 5.4L Lariat. It got so bad it was becoming a flip of the coin whether the truck would start or not. Sometimes easy; other times, I had to let the truck sit for up to 3 hours. The problem drove me nuts ! Two days ago, I let the truck idle from 12:30 pm until 5:15 pm because I was afraid it wouldn't start again.

So, what was the problem ? The fuel pump. I took it into the dealership yesterday, and fortunately, the mechanic had seen the problem before. He keyed the engine numerous times while checking fuel pressure, and he had a couple incidents where there wasn't any. He verfied that power was getting to the pump, therefore, it wasn't a relay or relay driver. He also said that a defective pump will not hold pressure on the gas line like it should when the pump is off; therefore, even if the pump spins up, there is no pressure against the injectors initially when a user quickly turns the key to engage the starter. That explains why I usually had some luck starting the engine if I at least held the key on for a few seconds before engaging the starter: the fuel pump, if it would turn, would re-build the lost pressure.

I can't guarantee that the fuel pump is your problem, but my symptoms were the same as described here. I haven't had the truck back but a day, but I drove all over and I must have started it 20 times today. No problem. Good luck, I hope this helps.

Steve, Maple Grove, MN

 

I would agree with Steve. I had the same problem as well on my wife's 98 Taurus. She runs a lot of small trips around town. She would make 3-5 stops and sure enough it wouldn't start. I picked up a fuel pressure gauge and took it with me when she was stranded just a mile from the house. Fuel pressure was 0. I bought a fuel pump at AutoZone and replaced the bad one. Simple change, and I felt good about it. But alas, the Taurus wouldn't start at all. I checked, re-checked everything. Finally gave up and hauled it down to the mechanic. He called the next day to say "Hey, you did a great job putting in the pump. Looks just like if one of my guys did it. Too bad you had a faulting part!" A brand new piece of crap fuel pump. After that and the TPS that I bought from AutoZone that last 4 months, I'm completely done with AutoZone.


kenjj2, pick up a fuel pressure gauge and when the problem happens next, check the pressure. There is a fuel rail that has a Schrader valve that the gauge screws on.

Hunt4Fun
Out of "the zone"

 

Getting bad parts from the parts store SUCKS! I had the same thing happen with a starter I bought from Napa - I ordered their best rebuilt & when it came the next day I installed it. All is well right? NOT - same problem, I then go on a wild goose chase thinking I mis-diagnosed the symptoms & as a last resort pulled the starter & tested it out of the vehicle, low & behold the starter was NFG. Luckilly Bill took it back & got me another no problem (I though I might be screwed due to it being an electrical item). Put in the new one & viola it started. I think these companies (rebuilders/manufacturers) must have some **** poor quality control procedures as theres no reason to get a DOA part like this IMNSHO. Anyway my wifes F150 5.4 had a hard start condition that so far has gone away when I replaced the fuel filter last week as part of some routine maintenance.

 

Same thing going on with my 2001 5.4 liter. The fuel pump issue mentioned is making a lot of sense now as I noticed that when I pump the gas pedal a few times before starting (to squirt some more gas in there) the hard start issue goes away.

gonna start looking into getting a new fuel pump. Truck only has 50k miles but the pump is still 18 years old I suppose.

 

First check the fuel pressure with a gauge. Pumping the pedal does not add gas.

 

Uh, this is a fuel injected engine. You don't have a carburetor.

Pumping the gas pedal does nothing except exercise your ankle.