RPM Jumps from 1200 to 2000

the rpm of my 6.5 Jumps from 1200 to 2000 no matter how much i try to feather it.I replaced the accelerator pedal and the fuel pump. took it to the local diesel experts. they told me it came that way when sold new??*Ideas Thoughts??

In neutral? Maybe not an issue.

I've seen "twitchy" throttles caused by the wrong (to high) resistor in the PMD, but, if you have a new pump that shouldn't be a problem. If it is rebuilt, it depends...

Is your lift pump healthy?

The 6.5 should NOT jump RPM that much.

You should be able to gradually raise the RPM from idle right on up to a very high RPM without the drastic jump.

Internal injection pump issues most likely to blame.

I would say that the fuel solenoid is getting worn and it is not responding properly.

I replaced the lift pump and PDM last year from leroy. thinking that would take care of it. sadly no.*I just spoke to my mechanic*about replacing the fuel solenoid. He tells me we should replace the injection pump at the same time to be on the safe side as it is the original.*thanks for the ideas of how to take care of the headache.
I will post on the outcome when finished.

Thanks again

If it is original, 23 years of IP service doesn't leave much to complain about, really. If you aren't seeing a STS (Service Throttle Soon) lamp/code, I agree with the suspect IP.

OK, I thought you meant the injection pump when you said "fuel pump". Yes, definitely, if it is original, it's a miracle it still runs!

When you replaced the PMD, what did you do for a resistor?

The fuel solenoid I referred to is not the shut off up on top, but instead the actual fuel control inside the INJECTION PUMP.

This part is not normally a local shop replaceable item..

A properly rebuilt injection pump that has been tested on a stanadyne test bench is the best route to go.

Good luck