VN SS hunting during idle

[maggot3064]

Hey guys have read **** everywhere and can't seem to find out what might be causing the problem. I have just put a motor out of a donor SS and got it going no worries except once it warms up it start hunting during idle (idle rises and falls to the point I think it's going to stall sometimes especially in drive) I have changed the temp sensor, O2 sensor, cleaned the idle control valve, changed ignition module, new plugs leads dizzy cap and button, set the timing to 10deg (in the correct mode) sprayed wd40 around inlet manifold and it still does it. I have gone through 2 sets of plugs because it seems to over fuel it self and they become like a black powder on the plugs(all except no2 cylinder does this) 02sensor seems to have taken the fuel smell away but it has me stumped why it keeps hunting.
Cheers any help would be great

 

[Deuce]

Does it have a miss (like intermittent spark miss) which could point to ign module faulty?
Or is it just the dodgy idle - such as an intermittent air leak?

First Question: Was the engine running sweet in the donor SS?

 

[maggot3064]

Nah no miss until if fouls the plugs lol which does take a little while. From what I got told by my uncle it ran perfect, I never got to hear it as the wiring around the battery had been fried due to a possum chewing in the wires.
Just checked the plugs again and they were fouled up again. Its doing my head in lol

 

[Deuce]

fuel pressure reg or return line blocked or kinked? causing excess pressure at injectors and over fueling??

 

[maggot3064]

How do I test fuel reg?

 

[Deuce]

check all vac lines and charcoal canister first.

 

[maggot3064]

Vac lines are all new,

 

[maggot3064]

I disconnected the wires to the map sensor while it was running and after a small little splutter it actually idled perfect. Would that point to a faulty map sensor?

 

[Darren_L]

is the check engine light on/have you checked for trouble codes ?

 

[Brisbarnz]

Tried the computer from the donor car? It may have a small cam and the computer in donor may be tuned. Would explain why it ran "perfect" in donor car.