Bad gas mileage with stock intake plenum

i just recently removed the supercharger on my 2001 Tacoma 3.4 and returned everything to stock. All vacuum lines are routed and there are no leaks anywhere. The truck has 60k miles on it and has had the blower on it since it was new. I was getting around 15-16mpg on Highway with the s/c and I am literally getting the same mpg with the stock intake. Anyone have any key point areas I should check to see what the hell is going on? Btw: tb is clean, maf is clean, air filter new, and I have the Arb snorkel without any blockages.

 

Sounds like good gas mileage to me.

 

I don’t think I should be getting the same mileage boosted as n/a though

 

Did you unplug the battery by chance?, it needs to relearn the new amt of air coming in, does it smell rich? If so the ecu still thinks it has the charger on it. Less air is coming in because its not sucked in, leading me to think it’s gonna take 300-500 miles to relearn just like when you put a charger on it.

 

What you want for that blower?
Does it not need a tune maybe? I’ve never looked into this but could it be a possibility?

 

I did unplug it and have ran 3 tanks of gas. I get around 240 miles to the tank. Just seems odd to me. Everything is clean and working so I’m at a loss. I guess I’ll see what happens

 

I have the blower, urd 7th injector, and all the goodies with it. (I still need to take out the high pressure fuel pump) but I’m wanting around 3k for the lot. It’s all clean and has fresh oil in it with no slip in the nose. Dm me if you wanna work something out!

 

Just leave the pump. Someone can source a walbro pump for cheap and wont hurt your rig. Forget taking that tank out. Lol.

 

So you reset the ecu and allowed the vehicle to relearn idle and what not? Actually, is that a thing for toyotas?

 

Total tangent, but I thought I probably didn't need a new thread. I'm getting a pretty consistent 19mpg with my v6 5spd. Is that pretty far out of the ordinary?

 

That's a thing for pretty much all ECU controlled fuel injected cars. The fuel trims have to settle out.

 

Hahaha yeah but the whine drives me effing crazy. I’ve never heard a pump that loud and on summer days in vegas it screams. Brand new too and walboro said that’s normal..

 

I think that’s probably right where you want it... I’m getting 15 or lower on highway driving and less in the city. Exact same mpg I was getting romping around with my truck boosted. You should be good! If you’re worried about it, get a new air filter, clean your tb and aic, and get new plugs and wires. Just tune it up.

 

Your highways and city streets, any hills, declines/inclines?

 

I feel you on that. Its why I installed a denso 190lph from an Evo Lancer. Flows enough for supercharger with no noise. It is normal for aftermarket pumps. Their nick name are "whineboro". Helps to keep the tank full.

 

I get 240 a tank also and so do lots of people on many other threads about gas mileage. There is over 20 years of evidence on the 3.4 that shows some are thirstier than others. You got a thirsty one.

 

Why do you think your gas mileage should change? Gas mileage is is based on the engine efficiency, truck body shape/weight and driving style. When you removed SC the only thing that changed was the SC weight, but that few pounds you would not see on your gas gauge. Truck body shape/weight at given driving style (acceleration and speed) determines the power requirement. SC gives you ability to get more power of the engine (more power, more gas) but if you did not drive pedal to the metal with your SC the power usage probably did not change much, hence no gas mileage difference.

 

Exactly. Well said.

 

Because driving under boost means you have less gas mileage because the computer is using more fuel with the forced inductionunde boost which happens a lot. Taking off the supercharger means better gas mileage as you’re not getting boost which is not requiring extra fuel. Also the drag of the supercharger is no longer there. Gotta take hp to make hp. Plus the truck was not tuned correctly with timing in open loop nor was it fine tuned with the 7th injector so fuel mileage would not have been at its best under those conditions Weight, shape, drag, are literally the top layer of it. Just trying to get the best mileage out of her as I’ve never owned the truck without the s/c. Can’t imagine that I’d get the same mileage.

 

dude ain’t that some shit... I read about people getting way better but also worse so I guess you’re right.