Hello!

My truck shut off on me only at highway speeds about five times this weekend. The first time it didn't lose power, just dropped RPMs steadily and then all of a sudden clunked back into full power. That happened twice, then it just dropped off completely so I had to pull over. Always when I let my foot off the gas for mergers. Somehow I was lucky enough to always be near a turnout.
Last night I cleaned the throttle body and replaced the gaskets, and it started beautifully (had formerly had a tumbly rough idle) and ran strong. Took it for a drive, everything felt good, and on a long stretch going about 40 I let off the gas and it dropped power again before kicking back into gear (maybe?) and letting me continue. I'm now looking at replacing the EGR valve and hoping that's it and not something way crazier.
I've scanned the forums but for some reason I'm having a hard time finding the oem Motorcraft part number for my truck. Does anyone know where to get a definitive answer on this? Between auto parts stores not having Motorcraft valves and places like Rock Auto and Amazon and ebay all saying the oem number is something different from the next place, I'm just wanting to find the right answer. Ford/Motorcraft websites are no help; all they show on a search is a spark plug or a windshield wiper. I just don't know enough to know that one or another is completely wrong for my truck.
Any and all advice on this welcome!

Thanks!

 

The first thing I would suggest is that you check the codes in your computer to see what it sees as a problem.

Engines are easier to diagnose over the internet when all the codes are listed, and in order of test.
KOEO - (O) Self-Test Codes =
KOEO - (C) Continuous Memory Codes =
KOER - (R) Self-Test Codes =

Make sure your A/C, Heat, Radio, etc. are turned off when testing.

 

Sounds good! I'll do that first.
Thanks!

 

An EGR valve, even stuck open, would not cause the symptoms you're describing. An exhaust gas re-circulation valve bleeds a small amount of spent exhaust (think of it as inert) into the intake manifold at high vacuum conditions, basically idling in traffic is what it was designed for. It surrounds incoming incoming fuel molecules with "nothing", separating them a bit and allowing for a more complete (cleaner) burn by improving the mixing with the O2 molecules. A very simplistic explanation, and good automotive text, will get into it in detail.

 

https://www.amazon.com/INNOVA-3145-Ford-Digital-Reader/dp/B000EW0KHW/ref=asc_df_B000EW0KHW/?tag=hyprod-20&linkCode=df0&hvadid=312158556601&hvpos=1o1&hvne tw=g&hvrand=13807015870205166521&hvpone=&hvptwo=&h vqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9008578 &hvtargid=pla-434264198620&th=1

 

Upon thinking, this could be as simple as the TPS or throttle position sensor. It tells the 'puter where the throttle is and if when you take your foot off the gas it shuts off the fuel, and upon stepping on the foot feet you're not getting the proper amt of fuel........ Just a thought

 

Deleted wrong OP....

 

oh I see it,
Deleted

 

Some of what you said is somewhat true...and not. I agree, consult the "good automotive text".

 

A good debate can be very helpful at times. This situation is being helped by vjsimone and he has suggested running codes so no debate is necessary for now. He is more than capable of taking care of it. JMHO Sandy

 

Work has been crazy, haven't had time to get the codes read but did order a reader. Have had time to have the truck shut off randomly at regular speeds from 25-40, so that's a new little monkeywrench. Last night it shut off and wouldn't turn back on for 30 minutes after repeated tries, then turned on like nothing had happened. Did some research, now thinking this could be the icm... any ideas?
I know I'm jumping the gun before I actually get codes read and know for sure but I'm just trying to think things through and isolate all the variables. Does this possibility make sense to anyone or am I way off?

Thanks again! Happy Friday!

 

Your ICM is on the suspect list.....
You Memory Codes may show some intermittent failures from your ICM.

Do you have a tachometer in your dash ?

 

Yes sir I do. On turning the key to accessory on a normal start, it hits about 200 before starting and I can hear the fuel pump click (I think that's what it is) and then climbs to normal around 1k at idle.
When it's done died on me, accessory sits at 0, doesn't move, and no fuel pump click. This will repeat until who knows what happens and then it works normally. Could be the second time trying to start it, could be the 50th. Last night stranded on the street at midnight of course was the 50th.

I just cleaned the throttle body and replaced the pcv valve, and at the same time cleared the memory codes. This was all in an effort to quit the dying but that clearly wasn't it.

 

Yeah, so you should put a few miles on it to hopefully to give the computer time to re-diagnose from the Memory loss.

One of the biggest myths is that computer codes negatively affect the engine operation, and clearing them will improve what ails it.
Clearing the computer also clears the Adaptive Learning the computer performs to improve performance over time.
Erasing this memory can cause the engine to run a little worse until you put additional road time on the engine.
There is a way to clear the codes without clearing the Keep Alive Memory.

The only reason I see for clearing codes is if some adjustments or repairs had been performed and codes are re-checked to see if the computer recognizes a change from the previously condition.

MPH is not as relevant as RPM since you can be @ 2000 RPM in every gear, and be traveling @ multiple/different speeds for a given/same RPM.

You could throw a New Fuel Pump Relay in to eliminate a potential intermittent issue with that device.

The ICMs start showing signs of intermittent failure when they are heated up before they fail completely. When they cool off, they start working again.

 

1K is a little high for a warmed up Idle.

How high does your Idle go in the first 30 seconds from a cold start-up.