Vs v8 idle problem

[eko]

Hi guys i had a standard 304 in the vs was running ok pulled it out put a worked 304 from a vn all i had to do was modify the dizzy plug and add a knock sensor on it the engine hasnt been run for 2 years i got the engine in cranked it runs nice but after it warms up the idle goes up and down drops as if its about to konk out than goes back up fluctuates between a couple hundred revs what could it be i got a new trigger/ignition module coil pack is month or so old new 9.0mm leads and irridium plugs bout month or so old aswell could it be because its not earthed properly or something and another nothe the injector rail off the vn engine didnt have the valve lookinh thing that sits were the petrol feed is and it isnt on there atm could it be because of that ?? Im stumbled atm

 

[Jake145]

Is the IAC stuck? I'd unplug it and see if the idle stops fluctuating, or after it warms and things expand your getting a lead in the manifold? Couple of theories
Good luck man

 

[Jake145]

*leak in the manifold*

 

[eko]

Ive listened around the manifold couldnt hear no hissing leak sound manifold got re siliconed and put back on ill try the iac tomorrow

 

[BottleFedVS]

That valve looking thing is the fuel pressure regulator if it is not there it won't run properly.
I suggest you take the New fuel injectors off the fuel rail and put them on the old fuel rail then fit that.
That may solve the problem.

 

[eko]

That valve looking thing is the fuel pressure regulator if it is not there it won't run properly.
I suggest you take the New fuel injectors off the fuel rail and put them on the old fuel rail then fit that.
That may solve the problem.

Its got the fuel regulator on the return side of the rail but at the feed side of the injector rail passenger side the fuel damper isnt there ill try putting it back on see what it does had a look today held the feed fuel hose when idling and felt it pulsing not sure if its meant to feel like that or just have the fuel running smooth thro the hose...

 

[BlackVXGTS]

When you say "worked 304" what do you mean? What modifications? Are you still running the standard VS ECU and memcal? Auto or manual? Aside from the idle, is the performance of the engine OK?

 

[eko]

When you say "worked 304" what do you mean? What modifications? Are you still running the standard VS ECU and memcal? Auto or manual? Aside from the idle, is the performance of the engine OK?

Its got acl race series kit flat top pistons 10:1 ratio stage 1 tourqey cam paper work is at home not with me for cam molly push rods block machined bored honed it was off a auto soo used my manual ecu on it performance wise no problems doesnt miss a beat while driving

 

[Brisbarnz]

The dampener on rail does help with pulsing but is not required to run. I know for certain vn 304 don't have one on rail. But do have on at rear fuel pump.
So yours is only an additional factory dampener.

 

[eko]

So some update i put damper on stilk the same check the ecu for codes not showing any errors im stumbled