TOPIC: Nissan Terrano VG3.3

Please help!!!
This Nissan I brought as a project car for Gadgetman groove. So far I have grooved it and blocked pcv new air filter and cleaned maf sensor rerouted evap and replaced plugs and up gapped them the car id running good but mileage is sitting around 13liters per hundred k. This is no better then since I have owned it. I have replaced manifold gasket to eliminate vacuum leaks. Next step to see gains would be.... thanks for any help. This car is emptying my pockets in to fuel tax and big oils pockets. And we can’t have that now can we:)

CJ - I have 2 thoughts for you:
First, the only Nissan I’ve Grooved was a Titan pickup truck that had the Direct injection engine, and I believe that is precisely why the owner saw a “dryer vent” exhaust but no mileage gains. I believe that with a direct injection fuel delivery, the benefits of the vortexes/waveform the Groove makes happen too soon in the induction/intake stroke for the fuel and air to mix properly/evenly. It could also possibly be that the waveform gets broken by the intake valves.
Second, the groove’s waveform might possibly be messing with the signal the computer sees from the MAP sensor. Have you tried relocating the sensor, if that’s possible? You might also consider electronically modifying that sensor’s output to the computer, or possibly relocate AND modify.
Might I suggest a simple experiment? Go back to a stock paper air filter rather than your new “high flow” “upgrade”and test to determine if the computer is simply delivering more fuel because of the increased oxygen content passing through the engine. If this shows an improvement, then relocate the sensor, and then resort to electronic intervention.

CJ, just noticed something in the one pic of the TB for this Nissan. The base gasket that's still attached in that pic looks thin and old. Gaskets compress when used, of course...

IT was the thin, already-compressed look of this gasket that got my attention. If there is a vacuum leak at the TB base- the ECU will simply add fuel to "cover" it up. Bye-bye MPG's!

Carb. cleaner carefully sprayed around the TB base will reveal any leaks.

Tracy G

Thanks Tracy but I have since replaced that gasket with a silicon gasket

Silicone gasket, what is it? Did you mean silicone from tube? As for me it is not the best way to prevent vacuum leaks. Plus when you tight bolts, silicon can be pushed out and make balls on edges. Try to cut a paper/carton gasket, and install it with a little grease on both sides.
Just a piece of advice.

Thanks for the advice