I have a 1998 F-150 with the 4.6L, just rolled 100k yesterday. Toady the truck has developed an intermittent no start where it will just crank and crank but never turn over. After letting it sit for a while it will start right up no problem. When the truck does not start as soon as I turn the key the o/d light "off" on the gearshift illuminates and stays lit. Any ideas as to what this could be? The fuel pump seems to be running. Thanks!

 

with the OD light flashing...that is trying to tell you you have a transmission code tripped...you need a scanner capable reading them....the average scanner at the auto parts store, in all likelihood, won't.

It wouldn't be a bad idea to get the fuel pressure tested. When was the last time the fuel filter was changed?

IF...you cycle the key on and off a few times, will it start then?

IS there anything else strange going on with the interior electronics?

do you have a slight front window leak? or notice this more when it is damp or raining?

 

He said the OD light comes on and stays lit, it doesn't flash.

 

The o/d light stays illuminated but goes off on the try on which the truck will start, which has no set amount of time
.
The fuel filter is a motorcraft with only about 8k on it. I figure they would last longer than that.

Nothing seems to be damp, as I just went over the interior with a fine tooth comb detailing it the other day after a rain.

Nothing else seems to be out of place other than the no start and the o/d light.

I have tired priming the fuel pump every time by cycling the key but have had no luck with this,

 

As comments only, I have a difficult time associating the OD lamp action with a starting problem.
There is normally no connection between them.
The OD lamp is either turned on by the manual switch or from the computer.
If your doing anything with the shifter position before cranking there may be faulty wiring in the shifter area that needs to be repaired.
On a no start it could be a number of things from the IAC stuck closed.
Test by holding a small amount of throttle on as you crank.
Otherwise test fuel pressure and the presence of ignition as a start.
A check for any codes set would be prudent.
You must develop a lead to the issues or it's all guessing.
Good luck.

 

I appreciate the responses but I have a new development to the situation. After driving it around today and having to "wait out" the no start situation I thought I had it narrowed down to the fuel pump. It wouldn't start so i had the key turned to the "run" position and I climbed under the truck to bang on the fuel tank to get it back home, while I was under there I herd an electronic buzzing sound coming from the transmission and the truck wouldn't start. All this is happening while the o/d off light was on. Finally got the truck to start and when I started it up at the house later the o/d light never came on, no buzzing sound, and the truck fired right up. Any ideas?

 

First , the fuel pump only runs about 1 second after the key is turned to 'run' then shuts off so you won't normally hear the pump run the way your doing it..
The pump restarts at cranking.
If you are hearing a noise from around the transmission, the computer is seeing a problem on the harness to or from the transmission and could be buzzing a solenoid on the valve body the computer detects as a fault (cross), and lighting the lamp..
This may be the place that involves the no start condition because the fuel pump control leads may be combined in the same harness at some point.
Investigate the harness from front to back for any damage, rub-through or burns from the exhaust.
I think this may be your intermittent trouble.
Good luck.

 

So what happened when you banged on the tank? Anything, - or have you found that the pump is indeed charging the lines ? Seems you aren't following thru in order to determine possible problems. You say bang on the tank to get back home, - have you done this before or what?

Also, you can't crank these engines for more than 4 consecutive seconds, - it shuts the rail down.

You should also check the trans fluid level correctly. If it's determined low, believe or not this can cause a no start.

I would also scan it again, - just to confirm nothing else is in the KAM. If the KAM is clear, I may try a reset. I'm not sure how to fish for trans codes, - haven't had to do that. Regardless check the KAM anyway before a reset. The CEL doesn't have to be illuminated to have a DTC stored in memory.

 

BTW- you have good people helping here, - great posts , listen to what's being said. It's all good info.

Also, I've heard them buzz like that underneath. I never did determine the cause exactly, but I would wager it was a solenoid like Bluegrass said. That was with a 98 E40D trans (4x4). I flushed the trans and used premium fluid to top it off after cleaning the accumulator body by hand and installing a Transgo "tugger" shift kit. That was 130,000 miles back. - Haven't had a prob sense.

 

When I banged on the tank it fired off but I figured it was just a coincidence because when it wouldnt start later I tried banging on it again and it wouldn't start. There is fuel getting to the rail according to the pressure test and pressure valve release method. I hooked up just a basic code scanner and nothing but it seems as if that o/d light "off" is illuminated upon turning the key and there is no buzzing the thing just isn't going to start.

I just got in from looking over the truck. All fluids are at their correct level and all the wiring around the transmission appears to be in order.

 

Rule out a fuel problem. Fuel pressure check during the not start is the fast easy way to do that.

 

Yea, the reason why you bang on the tank is to listen for the pump to charge the lines, - that's with the key in the run position. When the fuel pump begins to fail it usually fails to pressurize the fuel line from time to time. Banging the tank in the bottom middle is confirm the pump isn't always charging the line.

In other words, if you hit the tank and you hear(you WILL hear it) the pump charge the line, - pumps going out.

That's what and why. That's what you need to confirm.

Also, put your hand on the fuel pump relay just after have trouble starting it. IF the relay is warm to the touch, - it's bad.

You can't just look at things to determine the problem, - wish it were that easy right..; you have to listen and test along with understanding the purpose of. I'm sure your aware, -hopefully this will help.

 

I suspect you have an intermittent problem with the PCM booting up when the ignition is first turned on. Most common reason for that is a flaky PCM power relay. They're inexpensive and it would be worth your while to throw a new one in there. Aso inspect the female terminals for the relay as well as the PCM diode, and the fuses that supply the relay and the load.

Since the fuel pump (via its own relay), OD OFF lamp, and the transmission solenoids all are directly controlled by the PCM, it makes sense to go back to the common component which, of course, must have a stable and adequate power source to operate.

 

Alright I appreciate all of the ideas that have been thrown out! I let the battery sit unhooked all night long to hopefully reset anything that may have been an error in the computer. I went and replaced every relay and fuse in relation to the PCM this morning before re attaching the battery and so far, after some errands in it, so good. Its started up every time with no hesitation.

 

I have a similar problem with a 1997 F150. It DOES seem to be worse after a rain. I thought I had the problem resolved after cleaning some of the connections, particularly the pcm connector. I had a fuel pressure gauge connected and would get fuel pressure, but no start until after a long crank. I noticed that the injectors would open just before start.
After the last rain, again no start. Also, no fuel pressure. I can jump the fuel pump relay and the rail will pressure up. The O/D light is on. Any help would be very much appreciated.