mistapickles Posted February 5, 2012 Report Share Posted February 5, 2012 I have a great running car, fresh rebuild, 16g, hard pipes, bov, 3" exhaust with no cats and 40" of resonator. Sounds like a beast and spools instantly without the cats...my first trip to Las Vegas I got 20 mpg, this last trip I got 25 mpg so its pretty efficient...Here's the problem, I stomped on the gas to get past a truck and the richness of that secondary kicking in made my car wreak of uncombusted gas...I understand the cat burns unspent gas, but I'm spoiled on the spool times without a cat. Is there anything I can do to get my car to not waste that gas? My first thought was bigger turbo, cram more are in there so that gas has something to burn with, then I thought more spark but I am not a horsepower guy, I can make something reliable, but figuring something like this out, I'm not good. What do you think? Link to comment Share on other sites More sharing options...
JohnnyWadd Posted February 5, 2012 Report Share Posted February 5, 2012 msd coil and box and open the plug gap. Link to comment Share on other sites More sharing options...
Lance_S Posted February 5, 2012 Report Share Posted February 5, 2012 what are you using to control your fuel? If you have a MAFT you can pull a little out in the middle if you are safe on your AFR. Link to comment Share on other sites More sharing options...
Indiana Posted February 5, 2012 Report Share Posted February 5, 2012 Is that a small 16G? What do you have for a fuel pressure regulator and how much boost you playing with? What rockers arms and what cam do you have? Link to comment Share on other sites More sharing options...
Starwolf Posted February 5, 2012 Report Share Posted February 5, 2012 Sounds like you are just running rich to me? Link to comment Share on other sites More sharing options...
Technology Posted February 5, 2012 Report Share Posted February 5, 2012 Adding air requires more fuel. You want to use less air. Drive slower, get your car tuned, maybe swap a stock 2.0 4g63 in there Link to comment Share on other sites More sharing options...
mistapickles Posted February 5, 2012 Author Report Share Posted February 5, 2012 It's a stock fuel system with a stock fuel management system. It's a small 16g, with the stock FPR, stock valve train and I'm running 10 psi.... Link to comment Share on other sites More sharing options...
Indiana Posted February 5, 2012 Report Share Posted February 5, 2012 If you REALLY want to save fuel, take the BOV off. Link to comment Share on other sites More sharing options...
Starfighterpilot Posted February 5, 2012 Report Share Posted February 5, 2012 HMMMMM, Interior of the car "wreak of uncombusted gas" when seconary kicks in. Sounds to me like you have a leak at the secondary injector's seal to the TB top hat's o-rings. Do you have ANY evidence (brownish residue) of fuel leakage on the TB? Is the TB top hat tightly fastened to the TB body? Have you checked the hose from the PCV valve to the TB base nipple for holes or cracks and that the hose clamps are TIGHT? Change the secondary injector's o-rings and see what happens. For What It's Worth. KEN Check the FPR mounting nuts for tightness. When you are in boost, the increased fuel pressure may be JUST enough to cause the FPR's joint to the top hat assembly seal orings to start peeing gas. Link to comment Share on other sites More sharing options...
mistapickles Posted February 5, 2012 Author Report Share Posted February 5, 2012 @ Starfighterpilot Ok I checked the TB for leaks, no evidence of leaking, no brownish residue on the throttle body anywhere and I gunned it made it make the smell and pulled over immediately and didn't see any moisture at all around any of the seals. @ Indiana do you think when my secondary kicks in and my bov releases, it's releasing the unspent fuel from there? I don't have an ISC right now so when I take my foot off the gas the springs really shut the butterfly for a hot second. Link to comment Share on other sites More sharing options...
Komeuppance Posted February 5, 2012 Report Share Posted February 5, 2012 Install the ISC/MPS. -Robert Link to comment Share on other sites More sharing options...
Indiana Posted February 5, 2012 Report Share Posted February 5, 2012 BOVs DO vent out fuel especially when they are close to the throttle plate. The injectors are on top of the throttle plate, the plate closes, the BOV opens and that's why you loose some fuel but you loose more because the ECU dumps in the fuel for that air you released. You do get a cut from the TPS moving quickly in the throttle closed direction but when that's not working and the throttle cable is too tight and the idle tip switch isn't closing you usually have a backfire on full throttle up shifts. The BOV must have a strong enough to spring to stay closed at steady rpms without boost and just because you slightly lift the throttle to coast that doesn't mean the BOV is to open and most do. When that opens ALL THE TIME while you are driving just because your foot is moving up and not down, you lose fuel every single time you do that. When you drive your car, you move your foot up or down all the time unless you're on the freeway. Think of how many times you lift your foot and the BOV opens. Just because there's no boost you don't hear it but it likely is opening. To test how easy it opens, hold your rpms high, like 3000 or so, put your hand over the BOV opening now let the rpms drop and see how little it takes to get that to vent out air. The ECU expected that air to enter the engine and it put the fuel in for it. That causes your air fuel to go all over the place and the reading you see while that is happening is meaningless. Its not that there's no boost to assist in pushing the BOV open, its that at those high rpms like you would be on the freeway, there's plenty of VOLUME so it doesn't take as much vacuum to get the BOV to move. That's why I said, take it off. Drive around a few weeks without it and you'll save enough $$ to buy your lunch more than once. Link to comment Share on other sites More sharing options...
mistapickles Posted February 6, 2012 Author Report Share Posted February 6, 2012 Just got back from Vegas and decided I was going to see if the gas smell would happen if I slowly released the pedal after punching it, not making the air release sound....of course there was no gas smell....This BOV is a PITA, I have five washers in it because it leaked without them and my gas mileage was horrible, so I guess it has a new trick, atomized gas released into my engine bay... Are recircs any different? I don't recall having these kinds of problems with my last car and it had a recirc. Should I just cap it and call it a day? Link to comment Share on other sites More sharing options...
strang3majik Posted February 6, 2012 Report Share Posted February 6, 2012 A recirc would be much better, yes. Link to comment Share on other sites More sharing options...
Indiana Posted February 7, 2012 Report Share Posted February 7, 2012 Sounds like a cheap BOV. You can't change the RATE of a cheap spring with washers and I've not seen progressive rate springs in a BOV and that means putting washers in does just about nothing. A good BOV starts around $200. For the wasted gas over the life of your engine you could buy 5 turbos so there's not ONE person in here going to sell me on the it saves your turbo BS. BOVs are about the noise they make. Unless you are into drag racing they are just a pita for a MAF based fuel system. Link to comment Share on other sites More sharing options...
mistapickles Posted February 7, 2012 Author Report Share Posted February 7, 2012 I hate that noise, it's a cop magnet, the only reason I got the BOV was because I got a really good price on the hardpipes and it came with it. So you're saying there is no benefit to having a BOV unless you're drag racing, in which case you probably wouldn't be running a MAF setup anyway??? I going to weld this up, or make my own OVCP... Link to comment Share on other sites More sharing options...
strang3majik Posted February 7, 2012 Report Share Posted February 7, 2012 Use a 1G recirc valve and plumb it back in before the turbo. Cheap and easy. Link to comment Share on other sites More sharing options...
Indiana Posted February 7, 2012 Report Share Posted February 7, 2012 If the fuel system isn't MAF based it doesn't matter if you vent the air out it will make no change in fuel economy. The MAP sensor is inside the intake manfold. Just take the BOV off and put a cap over it. Link to comment Share on other sites More sharing options...
strang3majik Posted February 7, 2012 Report Share Posted February 7, 2012 (edited) DSMs have a MAF. Now, my SRT4 had a BOV and a map sensor...it didn't change a thing about that cars economy. Edited February 7, 2012 by strang3majik Link to comment Share on other sites More sharing options...
Tim_C. Posted February 7, 2012 Report Share Posted February 7, 2012 You still don't want the back pressure hitting the turbo. I always thought it would be cool to use the jet valve openings for some type of injection, like water or NO2, etc... LoL! Link to comment Share on other sites More sharing options...
mistapickles Posted February 8, 2012 Author Report Share Posted February 8, 2012 my last Starion without a blowoff or bypass....I don't feel I'm missing anything and that turbo lasted forever Link to comment Share on other sites More sharing options...
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