I have a 1988 F-250 with AOD Fuel Injected 5.0. It was giving me some problems like excessive roaring like noise when I accelerated, harsh and abrupt shifting, lack of power and recently rough idling. Now please understand, I am almost totally deaf and what hearing I do have is in one ear, therefor where ever that ear is pointed, that is where the noise is coming from. It makes it kind of difficult to locate unusual noises from an engine.
A hearing friend popped the hood and said my fan clutch was stuck so after a little work we had it freed up and the roaring noise disappeared.
He asked me to see if there were any open slots in the fuse panel Lo and behold, there were two! I put a 5 amp fuse in each and the shifting problem, rough idle and power issue all disappeared. I have no idea where the fuses went or how they came to be removed but gone they were. I still don't know what they control but whatever it is, it's important.
My gas mileage went from 11 1/2 mpg to 19 mpg and the truck ran great.
My friend pulled the distributor cap and said to go get a new one, now. So we replaced the cap and rotor.
All was well for a day. Then it began to run horribly at low speed and wouldn't even idle.
We checked sensors, connectors and vacuum lines with no obvious leaks.
I've changed plugs and wires, distributor cap and rotor, OCV valve, fuel filter and as of a little while ago, it was running awful.
last night I took it on a 20 mile drive and by the time I got back here it was running great. Four hours later I started it up and I was back to square one.
Help?

 

Could it have something to do with your nickname (poke, poke, nudge, nudge

On a vehicle that old (meaning one that doesn't have a sophisticated computer) it could be a sensor but I wouldn't be convinced that is it.

Have you checked the pressure on your fuel rail? What about your injectors? Also, your TPS (throttle position sensor) might be involved here if you have one.

 

His truck should have OBD1 diagnostics. I'd pull the codes, here's how:

Ford Fuel Injection » How To Run a Self-Test
Ford Ranger/Bronco II EEC-IV Testing

 

I recommend checking your fuel pressure because it sounds like a bad fuel regulator. I had a very similar issue with the rough idle and what not and that's what went bad on me.

 

if your at square 1 then how about changing your fan clutch ? then clean your throttle body , then check the fuel pressure , then pull codes , then change fuel filter ! not necessarily in this order !

 

I haven't checked fuel pressure (don't know how yet) but I did do a code check. Code 23. The throttle position sensor. The local auto parts store doesn't have them in stock so I need to order it. They do have a fuel pressure regulator so I guess I could go get that. If fuel is the problem it could be a bad pump, too, couldn't it? I do have a bad habit of running arund either very low on gas or running on fumes which I hear isn't good for the fuel pump.
It's so wierd. Yesterday I went to Tractor Supply and of course it ran real bad at low speeds. I got on I-95 and it ran fine. By the time I got to Tractor Supply, it was running great at high AND low speeds. It idled fine and started fine. By the time I got home it was running like crap again.

 

That does kinda sound like the Throttle position sensor now that I think if it. If you got that code, that's probably your issue so that's a great start. But, if you wanna check the Fuel Pressure, You need a gauge. Usually some auto parts stores do a Loan A tool deal where you can rent the gauge then get your money back. There is a valve connector for the gauge on your fuel rail. I'm sure someone will give you better info on that after reading this. It's easy.

Good luck!

 

In hindsight, I can see that the moniker was probably a bad choice, but it actually refers to the 5 acres of grass I have to mow.
I'm going to get a TPS and while I'm there I'll see if I can get the guage to check the fuel pressure.
If this keeps up for much longer I'm going to fall back on a strategy I learned many years ago in a land far, far away.

"There are very few problems in life that can't be resolved with the proper placement of high explosives" It never failed me back then.

 

Changing the fan clutch is something I know I should do. If there is any money left after this, it will get changed out. I got the codes and I already changed the filter.

 

I wanted to make certain the EGR valve was working. I checked out the vacuum lines and they were clear. I touched the solenoid and the cap on top fell off and the remains of what I am assuming was a filter disintegrated. I pulled it off to clean the junk out of it. On top I see a brass tubee and underneath the cap at the bottom is a spring loaded disc. Around the brass tube is a white (nylon) area. What, exactly allows vacuum into the line to the EGR? Something has to move or rotate or do something, right? As far as I can see, there are no moving or movable parts in this thing.
The disc on top of the spring is pushed down by something. What?

 

Here, read this to understand it
Ford Fuel Injection » EGR Vacuum Regulator (EVR)

 

Thanks! Great information. I looked at some of the links on the side and one of them was explaining different types of EGRs. Now, please forgive my ignorance here, they discussed an exhaust feed back or back pressure type of system. How can I tell if that is what I have?
Hypothetically speaking, if I had such a system, would a missing tailpipe and a muffler full of holes have an effect on it?

 

I'm not sure, but somebody will soon answer that.

 

Also, you should list the new codes

 

I did three things. Replaced the TPS, cleaned out the IAC and changed the thermostat. I only did the thermostat because it was staring me in the face and I knew it was stuck wide open.
It is fixed. It was a learning experience but I hope I never have the need for that knowledge again.
Thank you one and all for your most kind assistance.