...after it gets warmed up. I'll stop, put the auto into reverse to start backing up and the motor stalls/dies about half the time. Once I gain some speed backwards it smooths out. Only does it after it's reached operating temperature. Been happening for months in hot weather or cold. It feels and sounds like the (EFI) throttle body goes phsst - like choking out on a regular carb - and then the motor dies.

Anyone have ideas what might be going on with it? Here's a photo...

7.5L 460 EFI, E4OD. Looks like an EEC-V v1.0 OBD-II; the EEC plugin is on the driver fender behind the air filter.
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-First thing to do, is pull the codes
https://www.fordtruckzone.com/threads/how-to-check-codes-on-obd1-and-2-without-a-scanner.654744/
Post up any codes you have, and I will tell you what to look for
2nd thing to do is check for vacuum leaks.
I use carb cleaner and spray all the vacuum lines and intake areas. Yours is a part throttle problem, so you will have to check twice. First time at idle, 2nd time have someone hold the throttle at about 1,000 - 1500 rpm.
When you find the leak, the engine rpm will change

 

Thanks, I'll plug a test light into the EEC plug and see what comes up.

EDit: Doh! I mashed the test light moving stuff around. I'll get a new one in town next week. In meantime am checking the vacuum lines for cracks/brittle.

 

Pay special attention to the one near the throttle body that has an electrical connection, and goes down to the charcoal canister below the battery.
Not going to say why yet until we have some more details

 

I checked the line from the charcoal canister by the battery, looks good, no cracking. All the vacuum lines are 20 years old but look good, no cracking when I bend them, i keep engine compartments clean.

The EEC test plug on the fender well is identical to the 2nd picture in your first post (what year truck is that?) at
https://www.fordtruckzone.com/threads/how-to-check-codes-on-obd1-and-2-without-a-scanner.654744/

so this '95 is apparently a non-California OBD-I. The question OBD I or II for the 1995 year? seems like is asked every month. My Haynes manual and web sites are iffy on the 1995 year: "it depends on...". Basic code readers are going for $50 now, I'll break down and get one soon as I'm sure which it is.

 

The other truck is an 89, but the 460's were kind of a parts mix of their own. We are going to need those codes if the vacuum leaks check out.
you will be OBD2, which only means it will throw 3 digit codes.
few other improvements unless you see a mass air on your air box, and if your eec connector is behind the airbox that's not the case

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That little square thing on top of the tube right outside of the air filter box where the air tube hooks up is the mass air

 

I jumpered the EEC test plug and got the 3-digit codes from the the 'check engine' flashes.
With a cold engine-key on, it flashed 111 for 'system pass'.
Then after warming it up, shut it off and then key-on-engine-off the codes were again 111 and extraneous codes, like 536 because I didn't hit the brake, 538 because I didn't goose the gas, and 632 because i didn't cycle the E40D xmsn for a GOOSE test (I like that name).
Then again with the engine warm and running it flashed the 111 and those extraneous codes again.

Since the codes are good, in the next couple of days I'll go through the vacuum lines especially from the throttle body to the charcoal cannister. Thanks dustybumpers, I'm on track for getting that stall-when-shifting-into-reverse problem fixed.

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'95 F-350 7.5L EEC IV

 

There ya go!
Keep in mind, the red lines are full time vacuum, green lines EGR
Yellow switched ported, and black are switched not ported, usually will be hooked to a solenoid. White, and blue are heat related
These lines are abs, and DO NOT like heat, so they crack and break easy
Look behind the head, etc

One question, does your heater operate properly?
the black line into the cab by the evaporator box cracks, and that makes everything go to defrost

Also, look on the bottom of the Juice can if your truck still has one.
Most of the 94 up got a plastic one, but keep in mind, the 460's were step childs, they were only holding out for the v 10 to arrive.

 

BTW, I love your Avatar

 

Yeah I've gotta' watch out while pulling and prodding on that maze of lines and cabling around the engine. The old F250 is sooo much easier to mess with.

Thanks for the color coding. The heater works good in all functions; i'll double check the lines by the evap box. After 20 years some of those vacuum lines have got to be needing replacement, but they 'look' good. The "juice can" is that empty pollution thingy with a black line in and out, right?

That's Wily, an amazon. :fear: Your cat looks hungry

Tiki and Wily getting ready to smooch
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Actually not emissions thingy, that's your vacuum reserve can. extra vacuum for when that big 460 hast to use full throttle, and robs the vacuum, or if you get too many vacuum controled things going on at once

 

Nice to see you have the black master cylinder switch and what looks to be the recall harness!

 

Good eye!
That's actually a very inportant re-call. Ford put that in there, as well as all of my other trucks.
That piece contains a fuse, to keep the cruise control/ brake circuit from overheating, and causing a potential fire

 

As many fried Fords as I see at salvage sales I make it a point to notice that super important little detail. It is so sad to see so many go up in smoke!!
Apologies for the hijack.
Check your switches guys and gals!
"If it's red you're dead, if it's black you're ok Jack"

 

No problem! Good eye