My issue has to do with a sputter stall when my F150 engine reaches full temp. To restart, on the two occasions that it stalled (last two days) I have to wait about 40 minutes, at which time it starts right up, like nothing ever happened. There is no indication from the dash that anything is wrong, no check engine light, and all the gauges are normal. Both stalls/delayed starts occurred in heavy traffic and 90 degree temps.
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Having it towed off the freeway was not fun.
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Vehicle:
02-F150, supercab, auto, 4.6, K&M air filter, 76,000 mi.
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Recent service:
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Fuel filter replaced at 70, 000 mi. other than the recommended service, nothing else has been replaced to my knowledge (I have owned it since 06).
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The dealer thought it might be an electronic issue (idle, efi) but could not say why it started up after the engine sat for awhile.
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A Pep Boys Mechanic said it could be the fuel pump, but had no sure way to tell unless it was in the stalled/wont start mode – which it isn’t as it start right up after awhile, as I mentioned.
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I searched the forums here and could not conclude as there were a variety of topics covering stalls and hard starts, there was particular mention around air flow sensors and fuel pump failures, but nothing I could deem conclusive.
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Hope some one has run across this. I would like to have some ammo if I take in for a diagnostic test.
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Very appreciative,
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Michael
ffice:smarttags" /><ST1lace>Southern CA</ST1lace>
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When the stalling occurs and it won't restart, does the theft light flash off and on rapidly while cranking? This could indicate a PATS problem. Good luck!

 

Thanks for the response KingRanch,

I really dont remember, I'll certainly check for that when/if it happens again, though I keep comming back to why it originally stalled out and why it would take a "cooling off" period for it to re-start. If it does turn out to be anti-theft sytem related I will post it.
thanks again

 

A Fuel pressure check would be a great idea. However, a live data screen on a scan tool during the failure would be even better.......Definately check your fuel pressure.

 

Fuel... maybe, What makes me think electrical is. The pump in the tank is not heating up. I would look at ignition... of course you have to rull things out, so rule out fuel. When it happens spray fuel into intake. it should start right back up, if not, its ignition... I would look/ check, all grounds. Then I would check conection at crankshaft positioning sensor. I am not well versed with ignition on that truck, If it does not have individual coils, my bet is something controling the coil paks??

The old fords (late 70's) did that, you could pour cold water on the duraspark box, and they would start right back up. Ment the board inside was cracked. My buddies chevy had an intermittant problem like you describing, It was caused by, he was pressing his brakes, and a ground was not making a good connection, sending power back threw the wiring and into the computer. We redid his grounds and problem solved.

Sometimes even an irreguler diode pattern from the alternator can throw everything off. Have you had to replace the battery lately?

Good luck

 

Thanks for the reply Pintopower and Mustang,

I am intrigued by this issue, the fuel pump could be heating up then shutting down. I'll have to check the pressure at the rail next time with a gauge, but it has yet to happen again.

Forgot to mention, I did replace the gas cap -- as I had butchered the twister on top of the last one -- (so my chrome custom cover would close). I think the old cap may have messed with the seal/pressure in the tank. The new cap may have made a difference, well see.

In terms of electrical, these have seperate coils, and the battery is less than a year old. It also sits under a carport and the climate is dry (southern CA area), but I'll attempt to check all the grounds to the major components as soon as I can (thanks).

The only other issue I discovered of note, through searching this forum, was the consistent non-start sypmtons related to the PATS system/key being disrupted. And as in my case, most of those cases eventually resulted in a time-lapse where, once again, the vehicle would ultimately start. I just have to remember to look at the dash when I go to re-start as in all the cases mentioned the PATS ant-theft light will flash repeatedly, something also pointed out by Kingranch at the top of this thread.

Thanks again to all who have contributed.

 

Your into an issue with no direction to indicate what might be the cause.
This takes knowing something about how the system works in order to have a reasonable chance short of luck at finding the cause.
Here is a 101 on how the system works from a startng point.
Ignition key on looks at the temp sensors and operates the fuel pump for about 1 second to prime the fuel rails.
Next, the crank sensor detects the crank moving and begins the fuel pump again and starts to send RPM signals to the PCM.
The cam sensor begins the ignition timing process.
Any cables, plugs that are poor in contact could be a no start if they are temp sensitive.
Low fuel pressure, cam sensor heat sensitive, crank sensor faulty.
If the crank sensor is faulty, nothing will happen anywhere because this is where it all begins. No codes even can be set if the PCM does not get anything to work with.
So there is the field you have to play on.
A scanner (not a reader) to look at these functions would tell you quickly what is not happening, otherwise you have to check each function by observation in some manner.
Good luck.

 

Thanks Bluegrass, crank and cam sensors are something I was not aware of, I will do a thorough cable check as well. I'll post back when I get results.
m

 

I had a similar problem with my '08 where it would not restart after it was shutdown warm. It did not stall. No CEL but there was a code set. The problem was with the key transponder sensor loop in the collum. Sorry but I don't remember the code. I did post about the problem at the time.

 

This could very well be a PATS transponder error. Almost makes sense...

 

will report back after next incident/diagnosis.

Huge thanks to all for this info...

mh

 

Stalled the other day, again, and as before started up after an hour or so. Bought a fuel pressure gauge kit, pressure at the rail; 32-42. Ruled out PATS; no flashing PATS light.

Will check pressure at the rail upon next stall/non-start; hopefully this will let me know what end of the fuel distribution chain is creating the intermitent non starts. The only constant has been that this only happens after the truck has been running at full temp, and on all three occasions the temps have been in the 90's, but overall engine temp, according to gauge, is completely normal.

 

Have the codes checked. It may not show a CEL but still have a code in there . I'll bet it is the transponder sensor loop in the column.

 

Thanks shorebird, I forgot about that, makes sense to see if there are any codes in there, I heard Autozone will pull them for free, so I should probably head over there.

any one know the codes to look for?

 

Twilight zone is kinda wacky... I have seen them pull codes out of the sky... They will recomend your O2 sensors for sure... they always do...