I have a 97, 7.3 ltr. It is making funny sound almost like something ifs opening , hard to describe. But hanging from the bottom of the dash is a module with a plug in the side and a screen and buttons. the buttons across the top say RPM Control, Charge protect, Power. It has a Ford button / emblem and some buttons on the right side. they go vertically but I can only show them horizontally like so << < > >>. Is this some type of aftermarket device or what the heck is it??

 

Sounds like a Ford Aux Idle Controller.

Re. the sound, is it a whssshhh sound when you're trying to accelerate, and the truck is slow?

 

Yea, a heavy whooshing at the shift points. I had a gas mechanic listen to it and he was saying it is a programmer and a "waste gate" is opening. But he wasn't into diesel at all.

 

what does the aux idle control?. could the wrong button have been pushed causing problems?

 

A whoosh at shift points as your mechanic said is the waste gate on the turbo opening. The turbo is going from high rpms back down to a slower speed and it has to relieve pressure before it can do that. That's completely normal.

 

And the aux idle control lets you set the engine idle higher if you were say using a 1500 watt inverter you had set up or some really powerful off road lights. The reason diesels have this is because diesels idle so low normally that it isn't enough to run increased demands from the alternator(s). .

 

That sound is not normal and that is not a wastgate. It is called the exhaust back pressure valve. It closes when it is cold to help warm up the motor. They are know to be faulty in there old age and close when they shouldnt. There is a two wire plug under the turbo on the driver side. Unplug it and see if that fixes the problem.

 

It's not the wastegate. Our trucks don't have one. It's the EBPV - exhaust back pressure valve. Intentionally increases exhaust back pressure when cold, to warm up the engine faster. Lotta fellas wire it open, or even gut it. LOTS of threads on how to do it.

Aux idle controller only affects idle. It's out of the picture when you're going down the road.

 

Yeah obs trucks don't have a wastegate. They have an ebpv( exhaust back pressure valve) though. It is a valve on the turbo used to increase back pressure to aid in warm up. Does it only do it when cold? If it does it when warm you probably have to clean out the sensor tube. And the thing in the cab is a factory auxillary idle.

 

Lol. You guys beat me to it

 

this isn't just when cold so look for a thread on the exhaust back pressure valve??

 

where is this tube I need to clean out? is that the EBPV? Can someone link me with a thread dealing just with this subject?

 

The EBPV is designed to close when you start the truck when it's cold. It closes of the exhaust at the turbo and creates back pressure on the engine to aid in warm up. When they malfunction for whatever reason, they close at random times when they are not suppose to. The easiest thing to do is just unplug the wiring connector that controls it and leave it unplugged. It is located at the bottom of the compressor housing on the turbo just below where the intake connects to the turbo. It is a two wire connector and it won't hurt a thing to unplug it and leave it unplugged.

 

I got the valve cleaned out but what about the tube that feeds it is clogged, soaking with brake cleaner now.

 

There is no such tube that "feeds" it. Completely separate from (and irrelevant to) the EBPV is the EBPS - Exhaust Back Pressure Sensor. It's mounted (depending on model year) either just in front of or behind the HPOP reservoir, with a tube going down to the manifold (this is because, if it were mounted directly to the manifold, the heat would damage it). That tube, and the fitting in the manifold, and the sensor itself, can get clogged with exhaust soot. But it has nothing to do with the EBPV. The function of the EBPV is driven by TEMPERATURE (reading the EOT sensor).

It's good to clean out that tube, to avoid setting a code for sensor malfunction, but it won't affect whether/how the EBPV opens/closes.

Do you have the valve forced open?