Hey all,

I have a 1999 F-150 V6 5spd maual tranny w/ 216k on it. No check engine light or other symptoms.

This last month I have had problems with it starting on four occasions now. It will turn over fine but wont start. After several attempts it will start up and will be problem free for a day or two. I'm leaning towards the fuel pump or filter. I still have a filter tool when I changed it out two years ago. My questions are

1) How can I tell if it's the pump or not?

2) How much can I expect to pay for a fuel pump and are there any good online sources for cheaper parts?

3) How difficult is it to change out?


Any help would be appreciated. Thanks and Happy Holidays!

-Eric

 

Eric

My truck does same thing, and has so for the last 5-6 years. Anywhere from 3-4 months to as little as a couple of weeks before I have to repair it. In every case, it was the IAC valve.

To check yours the next time it acts up, try slightly holding open the throttle as you try to start it. If it starts, and runs as long as you use the gas pedal, it almost always is the IAC. If this is the case, remove and spray out the valve area with throttle body cleaner. let dry, and reinstall. Sometimes cleaning works, most times not.

I've never seen a fuel pump work intermittently, but if the problem was a shorted or corroded wire connection, I suppose it could.

Dave

 

Thanks for the response dave. I usually always give it a little gas while starting and when it was acting up, I pumped the gas a bit with no response. I'll try your method next time it acts up though, which shouldn't be long.

Another possibility is the crank position sensor. In the past, I've has problems with the truck dying while driving shortly after going over very rough, jarring roads. I would go and just press on the cable connection and it wouldn't happen again until I drove the same type of road.

-Eric

 

Eric

Pumping the gas probably won't work too well as the throttle body will just shut between pumps. You actually would need to hold it slightly open.

The crank sensor is in a bad spot for corrosion. If that is the problem, cleaning the harness and possibly the end of the sensor may clear it up .

Dave

 

cleaning the IAC certainly can not hurt.

I'd also be checking the electrical connections for corrosion as well as the grounds.
Also there maybe a fuel control module (FCM) over the rear axle...they also been known to corrode and crack...giving intermittent starting issues. Unclear if this includes the 99' ones or not....couldn't hurt to check though

 

Well, the problem seems to be getting worse. Twice today the truck failed to start up. After several attempts at cranking it, it fires right up and has no problem running or on any immediate consecutive restarts. Seems like when it sits for more than a few hours, it develops this problem.

I tried opening the throttle a bit while starting, but it had no effect. Thinking that it may be fuel pressure bleeding out while sitting, which would require multiple retrys to build up pressure again after sitting.

-Eric

 

If you turn the vehicle to the on position and bang the gas tank and all of a sudden it turns in the next couple starts it is prob the fuel pump though you should replace the fuel filter as well.

 

Eric

You do not mention whether you briefly hear the fuel pump activate when you first turn the key to "on". Does it ? On repeated starts, fairly close in time between, the fuel pressure may not drop much in the line. It will, however, bleed down if left to sit a while, which will require the pump to run ( the pump should come on every time you first turn the key to "on or Start". It would help everyone a lot to know if you at least have a working pump). If the pump energizes every time you try to start the truck, it's probably not the pump. But, if every time the truck doesn't start, you can't hear the pump kick on, well, that's probably, but not always the problem. Could be just the pump relay sticking once in a while.

Dave

 

Dave,

That was actually going to be my next step. I'm hearing impaired, so I would not hear the pump unless I was close to it. I'm going to have someone else work the ignition while I listen to see if it's engaging.

-Eric

 

Well, I've confirmed that the pump is not activating on each key-on. What's my next step?

-Eric

 

Eric
just because the fuel pump (FP) doesn't prime every time, doesn't always mean it is a fuel pump issue, for example, done in rapid sucession (a second or 2 delay between tries), may just mean that the fuel system is up to system pressure, & doesn't require activation. being hearing impaired, you will have a hard time picking this up. My wife is deaf in 1 ear, she can not pick up that noise.

Best way to determine fuel pump funtion is with a fuel pressure gauge....not sure exactly, but you should show somewhere 32-40psi just prior to going to start, or turn over the engine. If your only getting 10-20psi or is erratic pressure, yeah then it most likely the pump. It could also be the fuel pump regulator (FPR).

Just a thought,....you got plenty of gas in the tank?? yes? just checking

might be good to check the relays to the FP and the ignition .
have you checked for codes? Just because the light isn't on , doesn't rule out the possibility

 

Um, new here and reading through posts to see what possible probs I might encounter with my new to me 2000 f150. As an afterthought, does your truck have keyless entry? Does it unlock every time? The key fob has an electronic sensor and if the battery is low it doesn't transmit to the truck, it will not start. Just a thought mind you...not sure if it will help.

 

Next time it wont start look at the odometer and see if it reads the mileage or dashes. If it has dashes then the EEC relay is bad and not powering up the PCM. You could also look to see if the theft light flashes rapidly or proves out after 3 seconds. If it flashes you could have a bad PATS transceiver. Also FL, the key fob has nothing to do with the truck starting. The key itself has a chip in it that the transceiver reads and if it matches what is stored in the module then the truck starts.

 

Ack! sorry for the miss-info, thought it was the fob. Looked up the pats thing...i'll shut up now.

 

FL_F150: I do not have keyless entry on mine.


70f100longbed: Most of the time my odometer doesn't work. I believe it's the cold solder joint others have experienced but I haven't bothered tearing into it since it comes on intermittently and doesn't really bother me. I will keep my eyes open for it.

It seems like the truck wont start until the pump primes the line after sitting for more than a few hours. If it primes on the first key turn, the engine starts on that attempt. If it primes on the third or fourth, well then thats when it starts. It is geting worse though. Took me seven tries the yesterday.

-Eric