Ford V-10 shuts down at 4k RPM

[GQHabu]

For 18 days I have been awaiting a repair at a Ford dealership in College Station TX. It started when tranny downshifted for a hill. RPM jumped to 4k, engine stopped. No power steering/brakes. No warning lights. Coasting at 60 mph, shifted to N, turned key, immediate start up, put in D, continued. Ran ok until next downshift. Happened after 500 miles of my drive and no warning or warning lights., in dry West TX. No known external factors. After a few more occurrences, I nursed it to Houston for a medical appointment, then started home (NM). It happened some more during tranny downshifting. Finally, it would happen, start, but as soon as I tried to add gas, it died again. Coasted to a stop. Engine ran, but did not have enough power/rpm to move more than a few feet. Now finally had a check engine Lt and a wrenchs Lt. Towed to dealer. Stuck. Now $2000 in hotel bills, no rv. Please help. Have read some of your kind notes. Thank you! PCM is replaced. Will advise to try PCM to crank position sensor harness. Dealer now talking to Ford Fleet in Dearborn. Not helping so far. 2013 Coachman Mirada 32 ft.

[JIMBO34PA]

Wondering if trans range sensor taking a dump? Whats the codes ? Also maybe output shaft speed sensor shorting intermitant? You might want to take the gearshift and with engine off shift park to 1 up and back a bunch of times vigorously. The other thought is could the trans wire harness be chaffing somewhere back to ecm.

[puttin]

What a pain. Too bad you can't stay in the rig while it's in the shop. Wish you luck to a speedier repair soon...

[GQHabu]

Thanks, gents. JIMBO34PA, I'll check with the mechanic this afternoon. Thank you!

[Flyitall]

Any chance you are bumping the brake pedal while you are pushing hard on the gas? This is called a brake-over event and it shuts off gas to the engine. Don’t ask me how I know! Ford dealer showed me the brake-over event log on my computer which convinced me. The pedals are tight and I have big feet.

[GQHabu]

Flyitall: pretty sure I haven't done that. First time I was off all pedals on cruise control, when tranny downshifted and engine quit. Probably would not happen if downshift worked the way I think it should, ie downshift one gear only. Mine has always downshifted 2 gears, fifth to third for instance. Engine roars, sounds like it's going to disintegrate. Has always done this. I guess that's the Ford way! Never again!!

[John Hilley]

Do you have Trip Interruption on your motorhome insurance?

[twinboat]

Originally Posted by GQHabu

Flyitall: pretty sure I haven't done that. First time I was off all pedals on cruise control, when tranny downshifted and engine quit. Probably would not happen if downshift worked the way I think it should, ie downshift one gear only. Mine has always downshifted 2 gears, fifth to third for instance. Engine roars, sounds like it's going to disintegrate. Has always done this. I guess that's the Ford way! Never again!!

Don't give up on Ford yet. The 2016 and later use a 6 speed transmission and no skipping gears like the 5 speed.

[eddndee]

Please keep us informed as I may have a similar problem on my 2007. No power steering/brakes is scary!

[Mitzlplik]

Pretty much all newer vehicles come with electronic throttle instead of a cable throttle.
When these go bad you'll get the symptoms you are describing might ck into that.
Happen on my uncle's newmar it went into limp mode no warning just happened after trans started down shifting. Her kept stepping on throttle nothing happened.
Just an option to look at.

[amosnandy]

Sounds like a fuel pump. Yup. Computer is tied to fuel pump and RPM. What you are describing is the computer is getting a signal it does not know how to handle, and goes into limp mode.

I actually had a Ford Taurus that acted like that. Spent tons on it, ready to send it to the boneyard. Last ditch effort I threw a $30 used fuel pump. Ran another 120,000 miles.

My 2000 HR started acting the same way. I went right to the fuel filter, it was partially plugged, replaced filter and fuel pump, reset the computer and away it went.

[THenne1713]

One thing I find helpful in my 21yo rig (4-speed 4R100) is turn "OD OFF" early before hill climb, it delays the downshift so less speed loss too; your mileage may vary?

[PbdBlue]

Originally Posted by THenne1713

One thing I find helpful in my 21yo rig (4-speed 4R100) is turn "OD OFF" early before hill climb, it delays the downshift so less speed loss too; your mileage may vary?

There is no OD Off button on the 5 speed. 5 Star Tune cures 90% of the weird shifting in the 5 speed.

[THenne1713]

Does 5-speed not have the TOW/HAUL switch, e.g. same effect of locking out OD Gear?