Idle Surging Faster Then Slower On R32 Gtr

[Monsterless]

Here is the problem, the car starts up with a slightly fast idle around 1150 rpm and smooth, as it warms up the idle starts to get faster as the fuel air ratio goes down (11:1) and then the fuel air ratio goes really lean around (20.6:1) and then the engine slows down. So the fuel air ratio displayed on the wide band goes up and down with the rpm surge: Here is the back ground: The engine was taken out for major overhaul and everything was touched. Throttle bodies were match bored and no the shafts are not leaking air as I tested for that. The throttle stops were all backed off so the butterfly’s seat on the bores in an attempt to get the idle down. Yes I know this is bad but I am trouble shooting. The Air regulator for idle control is electrically disconnected in an attempt to get the idle down. The AAC idle control for the A/C is electrically disconnected in an attempt to get the idle down. There is now no fuel tank canister and the air bleed for it is blocked at the front throttle body. There are no Narrow band O2 sensors in the pipes but I never had them in before the engine was out and I programmed around their absence. There is a wide band but not hooked into the computer. The MAF’s were working fine before I took the engine out but you never know? I have Nistune and can program it but I have gone through it line by line changing values and getting no fix to the problem. Personally I think it is the fuel air ratio is changing for some reason and I am at a loss as to what it is causing it ? I do have some Z32 MAF’s but I have to wait for wiring plugs and silicone hoses to arrive to try that idea out. Is there anyone out there who had something similar happen to them cause this is getting to me?

[Monsterless]

Well it's not the MAF's cause I changed them. After it warms up the idle goes up and down, lean then rich.

[heller44]

Did you find a solution?

[GTR-N1]

Do you have the same problem?

[heller44]

Not any more.

Painful to find, but ended up being the hose going from the air chamber under the intake to the dump valves. Vacuum leak plain and simple.