Engine Stats and PCV Question

02NutStang said:

Im not sure if anyone has had this problem but my tubing from my PCV Valve (Passenger Side) is being sucked shut. I was wondering instead of going through the dealer, if I could put a small breather filter on the PCV Valve, and block of the vacuum fitting on the intake plenum.

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Doing this will result in a loss of the "positive" component of "positive crankcase ventilation." You may notice the oil fouling easier, a collection of milky residue building up under the valve covers and oil cap (because water vapor isn't being evacuated from the engine) and a nasty stench from under the hood when the thing is hot.

If it were mine I'd replace the tube that's collapsing and inspect the PCV valve.

My second question... I have a diablosport tuner, and I have it on a custom tune right now. I added a S&B Cold air kit, with a 75mm TB, and a bigger plenum with a spacer. I have SLP Exhaust. I richened the fuel to compensate for the increase in air. Can the computer compensate that much by itself? To be honest I havent seen any difference since I made it richer. Im wondering what other people are doing with similar bolt ons and their tuners.

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The PCM is told how much air is entering the engine via the mass airflow sensor. There's no need for artificial compensations as the PCM does it automatically.

As well, the PCM spends a great deal of its time in closed-loop operation. This means it's looking at feedback from the O2 sensors to compute corrections to the AFR to give something close to 14.7:1. Your modifier will only affect open-loop operation such as at WOT.

To be honest, unless you have a wideband I wouldn't attempt tuning fuel parameters. It's quite possible your engine would make more power with slightly less fuel but without a WB you'd just be guessing.

i had the same problem with my 02 gt i used http://www.latetmodelrestoration.co...tang-46L-2V-Gt-Pcv-Valve-To-Upper-Intake-Hose it works great even after 3yrs and u cant get it any dealer(at lest in nyc)