[jbl1]

I have a 97 powerstroke that I bought at auction.
It has 196000 miles. The main problem is that it after it warms up it sounds and acts fine up to about 2100 rpm at that point it blows white smoke and acts like its missing if you hold it after about 3 seconds the rpms will shoot up sounding fine but still blowing white smoke.
I have replaced cps
changed oil and filters
cleaned fpr screen (it was dirty)
It is not the ebpv ( that stays open)
The check engine light is not on and no codes show.
My scanner will not perform koer test it loses the link and cannot reconnect when truck is started.

 

[Excavator]

With those miles you might need injectors if all the basic stuff checks out.
I would pull valve covers when cold and check the harness's under the VC and the connectors, check the oil spouts while some one cranks it over. All spouts should spiut oil out the same. The IPR could be bad and when it warms up its not working right. It could be JUST DIRTY OIL as the oil is the heart of the HPOP and injectors

You could have injector poppets seats shot and depending on upper or lower seats worn it can run bad cold or run bad hot