Holding revs/runaway

[taff60]

Hi from down under. Regular reader but this may be one of my first posts.
Ok. So I recently had a set of injectors replaced after a lack of power issue. The motor ran fine with increased power after the swap. There was a slight issue of it smelling a bit rich and sooty, but it wasnt an issue. It was also noticed that if revved, it would be fine when you blipped the throttle but above 3000rpm, it was a little slow to return to idle. I originally suspected the cable or return spring, but the quadrant returns quickly to rest.
It has got worse. After travelling down a long shallow hill on overrun, when I touched the throttle, the black smoke was very bad and the revs stayed high.

When you blip the throttle from idle, there is no issue, but if rev it to 3500rpm it drops revs very slowly. If you go above 3500 t o 4000 rpm, it runs away to full revs. It doesnt keep going but holds at full throttle. It shuts down it I switch off the ignition.
So Im over fuelling somehow. But Im at a loss. These didnt happen before the injector swap.
As usual, help is appreciated

[Diezel Weazel]

Hi n welcome from uptop just for us reading, n so we have the gen on ya Truck is it a 2.4 or 2.8 Surf .?
What was wrong with ya old Injectors ? n do ya still have em ? or were they exchanged ?
FYI .. Nifty Nev on the OZ site may be able to help sooner ....

16+ Years of Surfs, n 9 years on Spotless it ain't but Faultless to a "T" is my KZN 130 Yota !!

[taff60]

Bugger, I thought this would list my engine in my profile. Its the 2.4 LT-E and thanks for the welcome
The old injectors were form new 317,000kms and one dropped out. It was ok ok idle but wouldnt fuel above idle. I had a 80% loss of power. I still have them and may get them rebuilt as spares. If i do, i am tempted to try them again to see if my issue is solved. I have checked the throttle body for leaks and checked all vacuum hoses, but there is nothing obvious. The black smoke looks like over fuelling, but it could also be an air restriction. As if tge throttle butterfly was fully closed but the pump wis still providing full fuel. I have a cheap chinese tps that i may try. Im just a little reluctant to start swapping out too mant bits.
Nev is a bit of a guru in these parts, he is a great help.