[Scar0]

I have an engine management question.
When my dad starts his rig, you have to wait till it to "Growl" before you can drive it. By Growl I mean that the RPM drop a little, it diesels a little and then it jumps back up to the regular RPMs.
If you do not wait for this "Growl", then you can only travel about 45 MPH Max. It has no power and just will not run correctly. If this happens, you have to shut it down, wait for it to cool off completely then restart and wait for the "Growl".
Ford has looked at it many, many times and has finally washed their hands of it. They said to just wait for the Growl and all is fine. This started about 3 months after he purchased it new. There are no Mods at all on his rig.
Any possible ideas what is happening?

 

[Mr Mac]

While my dad would have been the first person I contacted about this one I at least know what his first question would have been; how long, after you first start the engine, does it take for the 'growl' to occur?

 

[Scar0]

Sorry for not getting back to you sooner. I spend most of my time on the Nitro "Z".
Usually between 5 seconds and 2 minutes. It is longer when it is cold outside. But shorter if the rig has been running recently. If the rig is still hot, like when you add fuel, sometimes it will not do it at all and run fine. Other times right after a fill up it will not do it, and the rig will not run correctly (as in sounds like a miss, really rough idol, no power) without another rest and restart.
Makes you feel stupid sitting at the pump waiting for it to cool down... So you can start it and wait for the growl.

 

[Mr Mac]

Have you had the OBD system checked to see if there are any codes it is tossing out? Honestly it sounds like a fuel pump or pressure regulator acting up on you.

 

[Scar0]

No codes. That is what is strange. It has done this since about 3 months after he purchased it new. Prior to that, it started and ran fine.
It does run fine if you wait for the "Growl".
Every other diesel I have ever driven has not done this. Whether it be a Ford, Dodge, farm tractor, or 40' van-box Volvo.
Next time I am at his place I will see if I can get a video of it for you...