I have never had a truck, or car do this....Wife drivin the truck all day, with no problems. I replaced the headlight housings(what a fiasco....that is a WHOLE OTHER STORY), hopped in the truck to find a wall to adj headlights at, and the truck makes it 50yds down the road and dies. Restart...50yards, dies. Restart....50yards, dies!
It is a cold engine.
No codes.
EASILY refires.
351W in an 97 F250HD
Only happens when off of the gas(cruising to a stop sign).
This is outa the blue! Wife changed radiator cap(shes sooo kewl!) today, and I removed the whole damn front end to install headlights, but other than that, nothing different then yesterday?
Please help, Im on the edge with this truck. It is quickly becoming a huge mistake....

 

iac issue?

how well is it idling?

 

Have you pulled the codes, see what if anything the computer has to say about it?

 

It is idling fine. Just as well as usual.
No codes. It isnt even GETTING to Open Loop, yet before it is dying.
It has to be something stupid, trivial, and embaressing that I did when replacing those headlight housings or when my wife added fuel.
Fuel pump is engaging, btw...
Thanks!!!

 

let it idle until it goes open loop, will it still idle or does it stall?

Did you check the intake? that up front (hey its worth a look)

 

Yes, that is what I will be doing tommorow. Seems to have no issue idling, as it will idle much longer than it will drive down the road, but Closed Loop may prove different. Shall see......
Im just plain exhausted. Between rebuilding a Zuke QuadRacer 250R and the epic saga of simply installing new headlight housings in one of these trucks, I am just beat! lol
Its something simple...Im sure of it, my mind is just too numb to think right now.
Any ideas are apreciated, and yes, the intake is worth a look.
Add that to the list!

 

You probably missed a ground? Ground "E" Radiator support, near drivers side top end of radiator perhaps? (my book, this forum, end at 96 model year)
How much you had apart is hard say, only you can really answer that.

Running the KOEO test may just lead you to the problem, open or closed loop modes have nothing to do with it.

 

Im hoping so, though I never disconnected any grounds(to my knowledge) shall see tommorow.
But, how does the operating mode not have anything to do with it? The paticular operating mode that the vehicle ECM is in has everything to do with if the ECM will recognize a failure(i.e. TPS, MAP, Missfire). Granted, this is due to knowledge with GM products, but the whole purpose of ANY of the OBD systems was to try to streamline engine operating proceedures(all emmissions B.S. aside).
I am not trying to be rude, simply asking. I hope I can pull codes and be wrong! lol That would make life much easier! I am new to these trucks, and Ford in general.
What does KOEO stand for?

 

Ah noticed your year after I posted adding that fact but didn't edit the rest of of my post.

If its OBD2, and it probably is? then it will depend on what kinda scanner you have.

Is it OBD2?

 

It should be, however, in fords infinate wisdom, I have an elect model of truck(of course! lol). It is an 97 F250HD...HD, somehow, somereason, means ford kept it an OBDI system

 

I had read some of the 97 F250ies retained the OBD1 system, was still exempt at that point, wasn't sure if yours was one or not.

So ok then you can run the self test "KOEO".

How to run a self test> http://www.fordfuelinjection.com/?p=13

 

Ok. Update.
Went out fired the truck up.
Let it idle for 15min- no problems.
Went and put it in gear, and it seemed to bog a little till I have it more gas(more than 200rpm or so).
Went down the road and drove hard, easy, stoped, cruised...everything. No problems.
I havnt done anything to it since last night.
Im thinking the ignition control module, though it usually acts up when the engine is warm.
This is odd....

 

Im updating this thread for 2 reasons:
1. Im a glutton for punishment, and I deserve any ridecule I am subjected to due to my stupidity.
and...
2. Just in case any one else has the same problems.

Quick briefing of scenario:
Truck cranks fine.
Truck idles ok.
Accelerates fine.
BUT.....When you let off the throttle WHILE THE ENGINE IS COLD the truck dies, yet, ALWAYS restarts.
If the truck is allowed to IDLE to operating temperature, it will not die.

This is a typical case of overthinking myself. Making things more difficult than they actually are, or need be. As often happens when we deal with newer vehicles that are 'computer' controlled, we tend to aphixiate on the hightech, technical, and 'foreign' aspects of its design. We get into a psychological pissing match of sorts with the ECM, trying to 'think what it thinks'....use cause and effect, determine why the 'computer' is causing the truck to do/or not do the problem at hand.
Sometimes you just have to think outside the box, by thinking IN the box..
What are the 3 primary things a gasoline engine needs to function?
Air
Fuel
Combustion(heat, compression, etc...)
Air filter, ducting, tract and TB were fine and unobstructed.
I knew it wasnt an ICM issue, b/c that is often a heat related failure...it fails as heat INCREASES. This is the polar opposite of my issue.
I knew I was getting fuel(fuel guage), and once again heat, if in the case of a bad fuel pump or relay, would have NEGATIVE effects on operation.
What is the ONE thing(that I can think of at least)that NEEDS heat to fuction???
SPARKPLUGS. They were soooooo old that the electrodes were carboned all to holy hell.
"This is a stupid problem to have, but it is a problem, nonetheless!"compliments of Bad Boys II
When the engine was cold, and not under load, they could not produce enough spark to maintain engine operation...as the engine's heat increased, and the ECM took over control of A/F ratios, the truck would operate(not great) but it would keep movin and maintain.

Moral of the story. Dont make things more difficult than they are.

Thank yall for your help!

 

Glad you found it.

 

Thank you, sir!