6.5L engine to runaway when idling
 

Hi,
I'm looking for advice on a 1999 6.5L. Here's the symptoms:

With the first PMD, the engine would idle normally but if I tapped the accelerator the RPMs would spike up.
With a second PMD, the engine would idle normally for 10-20 seconds but then RPMs would spike up without me touching the accelerator.

I did the LiftPump test, fuel comes out the T-vavle hose. The previous owner replaced the IP several years ago but I don't know the quality of the current pump.

Any assistance appreciated. Thanks

The new PMD seems to have settled down now.
This thread can be closed. Thanks.