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GUYS I AM GETTING 130 MILES TO A FULL TANK OF GAS!! it all started after my tune although my tuner assures me its not the tune doing it.
I have 42# injectors and a 255lph fuel pump if that helps.... what else could possibly be doing this? Its almost to expensive to drive the car ANYWHERE!!

any help is appriciated!
thanks

btw: its not my driving! i kept it under 2k rpms for an entire tank of gas and still only saw 8 or 9 mpg!
thanks
 

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I think I know what the problem here is. Youve got quite abit of boost and you need more fuel. The enormous amount of boost is probably creating a vortex in your manifold and actually sucking fuel. Id consider getting bigger injectors, pump, inline pump, and bigger fuel lines. Good luck.
 

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SIRSARKAZM said:
I think I know what the problem here is. Youve got quite abit of boost and you need more fuel. The enormous amount of boost is probably creating a vortex in your manifold and actually sucking fuel. Id consider getting bigger injectors, pump, inline pump, and bigger fuel lines. Good luck.
:lol: what a comedian...

anthony, are you sure no one is siphoning the gas out of your car?:confused: if that isnt happening, then you are running PIG rich....or you have a fuel leak somewhere. start your car and use a cigarette lighter to find the leak..shouldnt be hard to find that way!!!
:lol:
david
 

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Are you sure you need 42# injectors. I am running the 9# SVO system on stock heads (for now) and seeing 11# of boost with no detonation on the 30# injectors supplied with the kit. I get on average 200-220 miles per tank in town. Sounds like pig rich to me.
If you have a CAI you might want to dump that and put the stock air box back on. Removing mine made a big difference to both HP and fuel mileage



Dwayne
 

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What does it matter what size injectors he is running. This isnt a carbed car,. its fuel injection and the unused fuel goes straight back to the tank:rolleyes:
 

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Does the 96 have a fuel pressure regulator or the returnless system?If you have a FPR with a vacuum port on it,check the diaphram,if it's busted it will suck gas straight into the manifold.I would also check the computer codes.A whacked o2 sensor can cause it to run rich.If all that checks out I would suspect something in the eec chip.Sounds like it's using the wot fuel curve all the time.I would also check your oil,if it's running that rich and your oil smells like gas,you might want to change it frequently until you get this problem solved.
Good luck,
Billy
 

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Returnless came in 99
 

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if it didn't start until after the chip! remove the chip. drive it for one tank and see how it does! maybe you got a bad chip! jmho.
Leon
 

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How are your o2's? What fuel pressure? If both of those are acceptable, than it IS the tune. The lightning is blown with 42lb injectors, and I kinda have a feeling it gets more than 8.5 miles per gallon.

Take it easy!
josh
 

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You should have a big enough pupm there I would recommend going to a smaller injector ! Maybe 30 ? Not 42 ! 24's and a good tune maybe ?
 

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Crazy people

SVOSALEEN. Your injectors are not the problem and your fuel pump is plents for 330 rwhp. This thread should be for svo people.

24#'s LMAO......the s/c alone uses 30#'er's.

You should check the 02 sensors. If that isn't it, check your fuel pressure. With your setup you really should be using an adjustable fuel pressure regulator.

Let us know after you check those. I just put in new O2 sensors with my longtube install and my gas mileage is freakin awesome. I got like over 300 miles to one tank (all highway).
 

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FirstOnRaceDay said:
Does the 96 have a fuel pressure regulator or the returnless system?If you have a FPR with a vacuum port on it,check the diaphram,if it's busted it will suck gas straight into the manifold.I would also check the computer codes.A whacked o2 sensor can cause it to run rich.If all that checks out I would suspect something in the eec chip.Sounds like it's using the wot fuel curve all the time.I would also check your oil,if it's running that rich and your oil smells like gas,you might want to change it frequently until you get this problem solved.
Good luck,
Billy
my thoughts exactly...i believe it is in the tune. like using the WOT curve all the time. i warned anthony about getting CJ to tune the roots car. you have to tune both variables WOT and part throttle.
like it was stated before, the unused fuel will run back into the tank. the injectors are not the problem. 30# injectors with this setup are a problem even if some are having luck with them. they are borderline.
anthony, try this...take your car to houston performance and have steve tune it. if steve cant tune it to where it is better than it is now, i will pay for the tune.
david
 

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Thats about the same mileage I got in my last 2000 GT. Completely stock, it regularly got between 120 and 160 miles per tank. In the 28,000 miles I put on it, I never did see 200 miles/tank. I think the worst I got was 85 miles/tank (14 gal).
 

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98Roush said:
Crazy people...You should check the 02 sensors. If that isn't it, check your fuel pressure. With your setup you really should be using an adjustable fuel pressure regulator.
Crazy people, huh? Looks to me like you recycled what I've already said. I guess you don't have to have an SVO blower to know something about forced induction?

josh
 

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94MustangGT-215Hp (stock)
march pullies +15hp
BBK Shorties +10hp
BBK Off-raod pipe +20hp
BBK Cold air +10Hp
65mm Throttle body +10hp
Mac cat back +15hp
FRPP 9mm plug wires +5hp
K&N filter +10hp

ESTIMATED HORSEPOWER- 315hp

:lol:
 

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SVOSALEEN..what thermostat are you using? The one included with the SVO S/C kit? Have you noticed what your temp has been? If it's running too cold, the ECU is gonna order up more fuel. I had a very similar problem on my wifes vehicle. Sure enough, the thermostat was stuck open causing the vehicle to run too cool, and thereby running VERY rich. Maybe you've already covered this base...just throwing out an idea.
 

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Ray's 88 GT said:
94MustangGT-215Hp (stock)
march pullies +15hp
BBK Shorties +10hp
BBK Off-raod pipe +20hp
BBK Cold air +10Hp
65mm Throttle body +10hp
Mac cat back +15hp
FRPP 9mm plug wires +5hp
K&N filter +10hp

ESTIMATED HORSEPOWER- 315hp

:lol:
I doubt you're really running 315hp. Just because the box says "up to xx amount of hp" doesn't mean that you'll get that much, just that you can get up to that.
I had basically the exact mods that you have on my last GT with the exception of the TB but I had a chip to back that up and I don't think I was even near 300hp. If I had to guess, you may have between 260-275. JMO.
 

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92StangMan said:


I doubt you're really running 315hp. Just because the box says "up to xx amount of hp" doesn't mean that you'll get that much, just that you can get up to that.
I had basically the exact mods that you have on my last GT with the exception of the TB but I had a chip to back that up and I don't think I was even near 300hp. If I had to guess, you may have between 260-275. JMO.
I'm thinking the screen name of SIRSARKAZM (Sir Sarcasm) might have something to do with those hp estimates. ;)
 

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When you don't run your car at WOT, the EEC is constantly adjusting the fuel trim (injector pulse width, etc.) to attempt to maintain nearly stoichiometric (complete) combustion. I won't bore you with the formal definition: suffice it to say that the EEC wants to maintain nearly 14.7:1 A/F ratio throughout the continuum of throttle position and engine speed.

The way that the EEC does this is through short term and long term fuel trim tables that essentially store, for several points in the abovementioned continuum, adjustment values (+ or - a certain percent) that are applied to the fuel program to bring the resulting A/F closer to the target.

It takes quite a while (driving a car regularly) for these fuel trim tables to adjust everything to optimum, especially when you might start with a system component or a tune that is a bit out of whack.

So, it's very possible that your mileage will increase with driving time as the EEC adjusts the fuel trim. Of course, none of this applies to WOT operation.
 

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Pull_T said:


I'm thinking the screen name of SIRSARKAZM (Sir Sarcasm) might have something to do with those hp estimates. ;)
LoL I didn't even see that. I guess I'll have to be more observent next time :D
 
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