I own a zx2, and one thing that get them better gas milage is disconnecting the knock sensor and running a 5.6k ohm resistor on the positive wire from the IAT. I did this and it does work, I also did this except the knock sensor to my sunfire, I am seeing about 80 miles to a 1/4 tank. Will this mod work for the sunfire. Also there have been test for the zx2 and a 2.6k ohm kills milage, while the 5.6k give 5-8 miles pre gallon better.
M
http://www.overkillengineeringmotorsports.com/
so.... you lean out your afr, and disconnect your knock sensor so you're engine cant tell when it's gone too far and knocks, and this is a good idea for the same gain as... not getting into your pedal as much? sorry, do not want.
JBO Stickers! Get yours today!
No, the knock sensor on the ZX2 is very sensative, if you touch it it retards the timing. I will post the link later. i did not disconnect mine on the sunfire I just did the resisitor.
http://www.overkillengineeringmotorsports.com/
This is extremely foolish. Don't do it. You don't have the instrumentation to be able to tell how much better/worse a mod is. I have both a wideband AFR and an MPG meter, and trust me, it won't make a difference other than possibly risking knock. You will only be leaning out the AFR during wide open throttle operation, when you want to lean out the least. AFR is decided by the O2 sensor during closed loop operation, nothing else. I've leaned out my car the right way, with a wideband. I run 16.5:1 AFR in closed loop mode and 12.5:1 at WOT and there are gains to be had, but not the way you're doing it. Also, by using the notoriously inaccurate fuel gauge, you're in no position to make MPG measurements.
2002 Cavalier 2200 5spd
i would rather have worse gas milage before ever considering disconnecting the knock sensor.
Morons, they're everywhere!
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
In order to clear some things up for you. The knock sensor on the ZX2 is overly sensitive. It randomly pulls 6* of timing through the entire RPM range for no reason. You can even feel it when driving. This has been verified in many data logs. Even the factory PCM program ignores the knock sensor above 6000 rpm, so from the factory it is known to be useless. When you buy any chip from Superchips or SCT for the ZX2 the knock sensor is disabled by default. I'm running 8 pounds of boost with my knock sensor disabled and the car doesn't knock. As long as you use good fuel there is no risk of spark knock.
This might not work on a GM car because of how poorly engineered they are. I'm not saying Ford's are better, Ford actually sucks, but the 3rd gen Escort does get the Consumer Reports 'Best Bet' award for every year it was made. (half of the 'Avoid List' is GM) Furthermore, the ZX2 uses a lot of Mazda parts. Since Mazda has more to do with the car then Ford, this explains why they run so well and last so long. I actually won't buy a Ford car and the only reason I keep this one is because the Zetec engine has been race proven and the rest of the car is based on Mazdas small 'BG' platform.
As for the IAT mod, many tuners have reported better MPG. The only issue with this is that our PCM learns. So, over time, it may re-calibrate the sensor to get the correct reading. I get 32-36 MPG from my wifes' ZX2 with just a chip, larger cat-back exhaust, and a modified (keman) intake. A chip will make more efficient use of the given amount of fuel (mostly by advancing the timing) and increase the power output of the engine so it doesn't have to work as hard to move the car.
There is no need to call the guy a moron, he has done his research which seems to be much more then you are capable of. He was only wanting to know if it would work on the sunflower as well. He already knows it works on the ZX2 because it has been proven in thousands of cars already.
T3 Super 60 at 8 psi, FMIC, 2.5" charge pipes, HKS SSQV, Ford Racing UDP, MSD coil, SCT Xcal2, B&M shifter, S/R cluster (150mph), Eibach Sportline springs, 19mm RSB, ES bushing kit, Trubendz 2.5" stainless steel exhaust w/ resonator and Borla ProXS, custom LED brake light bar, Phantom Grip.
If you hadn't noticed, there are a lot of idiots on this board. Some are long time members, others are new trying to get started. Just ignore them and read the generally useful posts that do appear from time to time.
In short, nobody here has had luck messing with the J-body engines in that manner as far as I know. Give it a shot and see what your results are. "Most" of the resistor mods for the IAT are garbage for our cars.
