Rb26 + Nismo Plenum

[Piggaz]

Hey guys

I have just installed a Nismo plenum on my GTR. I turned her over last night and she idles at 3000 RPM. No hunting or coughing. According to my wideband it the Air/Fuel ratios are the same as they would be with the stock plenum which would indicate i dont have a leak somewhere. Any ideas? Gaskets are new Tomei metal items.

[Cjmartz2k]

A boost/vacuum leak test is super easy to do and will eliminate that possible problem right off the bat.

[Adriano]

Did you clean the throttle bodies?Have you adjusted the throttle linkages?

[doo doo]

Have you tried adjusting the idle solenoid? (unplug brown plug on idle solenoid under rear of manifold with engine running, unscrew phillips head screw until idle comes down to where you want it, plug back in and it's reset)

[blind_elk]

3000 rpm idle = massive air leak.

You've left a hose off somewhere - I would start looking around the cold start valve.

[Piggaz]

OK

I didnt touch the throttle linkages.

I didnt clean the throttles because i know it causes this problem.

I havent touched the AAC valve yet becasue wheni started it, it was almost Midnight.... I dont think the neighbours would appreciate that one.

I have the dowels the right way too... I knew about that issue before i started!

I have racked my brain over night and i cant think of anything that i have left off...

I know its a long short but is there any chance because of the different shape of the stock plenum it would make it idle that high... i dont think it would???

[Cjmartz2k]

Dude, do a freakin boost leak check and find the huge leak you have somewhere. If you don't know how, google it. It took me $10 worth of parts from the hardware store and 20 minutes to put one together.

[blind_elk]

Had the same problem when I fired up my RB25DET after a rebuild. Turned out my mechanic had left a hose off one end of the cold start valve (not the AAC). Check every hose again.

[GTR1993]

do the leak test, idle high needs air, air has to be coming from somewhere.

[Adriano]

The different plenum may well need the throttle linkages to ba adjusted to suit.

[Piggaz]

A little update...

Adriano i think your on the money with that one. I have just adjusted the linkages and everything has retuned to normal! Why didnt i think of that before!