Idle Problem and Intake Manifold Leak?

[Chim55117]

Hey guys,

So I recently started my new build and everything seemed to be OK with the exception of a few things.

1. There is a sucking noise coming from my intake manifold, not my intake with filter, my intake manifold. The "leak" isn't coming from the throttle body, I'm sure of that. I can't feel any air leaking out either.

Is that sucking noise normal?

That ties into my next question.

2. For some reason, my idle is stuck at 500 RPM. If I back in or back out the BISS, there is no effect. Is there something wrong with my TB? Or would it have to do with my intake "leak". I put leak like "leak" because I do not know for sure if it is one.

And I know this is a VR-4 forum but...

1G-A love...

Thanks in advance.

 

[turbowop]

Screwing the BISS in or out does nothing without grounding the proper terminals to keep the ecu from affecting the idle. You'll just end up making any idle issues you have worse by not doing the adjustment properly and centering the ISC via terminal grounding.

To figure out if that sucking sound is a leak, do a boost leak test.

 

[Armitage]

Yea, you're going to have to determine and fix the leak before you can address your idle issues. Typically, once all the leaks are fixed, idle problems are because of a) bad air metering device (less likely), b) bad TPS calibration (very likely if it's ever been played with), c) bad ISC coil (happens when car gets older). Procedure to test and calibrate b) and c) are on the VFAQ.

 

[Gimpin]

a can of starting fluid can also help you see if you have a leak ... if the engine revs when you spray the starting fluid in the suspected area then you have a leak /ubbthreads/images/graemlins/smile.gif