The best i remember when i last tuned my maf With the stock injectors i had good fuel trims. Now using 42lb green top ford injectors which I believe are 45 on my rail. I hafta set them to 39lb to have acceptable long term fuel trims and it's still around a positive 10 ltft. Any ideas? Should I use the 42\45? And maf tune? the fuel trims won't be able to compensate. i kinda thought this part would be easy.
2001 3.8 v6 camaro, T5, ford 42lb green top injectors, grand national .63 a/r turbo. 8psi. stock motor, ngk tr6 plugs (one step colder) 91 octane.
2001 4.3 zr2 s10. daily driver, 31" tires, 4x4, cat! and exhaust. looking for mpg.
since the last tune. its gotten different exhaust manifolds and currently there isn't an air filter on the intake. nothing done to the motor internally. the exhaust is routed into a turbo but im not actually boosted yet. i think it would be best to use the injector data but it runs so lean.
Last edited by thebeewantsboost; 08-16-2011 at 12:31 PM.
2001 3.8 v6 camaro, T5, ford 42lb green top injectors, grand national .63 a/r turbo. 8psi. stock motor, ngk tr6 plugs (one step colder) 91 octane.
2001 4.3 zr2 s10. daily driver, 31" tires, 4x4, cat! and exhaust. looking for mpg.
1. Use injector data.
2. Use VCM Editor\Tools\Unit Conversion\Fuel Injector Calc
3. Ford spec pressure is the "current" pressure in the calc. Ford spec flow is the "current" INJ flow in the calc.
4. New pressure is YOUR rail pressure.
5. New INJ flow is what you set your IFR vs kPa table to.
Google is your friend:
All from Ford Tech Support (800) FORD788, 1-800-367-3788
Ford SVO Green Top 42 lb Fuel Injectors
Ford Part # M-9593-F302
Bosch Part # XL3V-A9A and 280150558
42 lb/hr. @ 39.15 psi
Minimum Pulse Width: 1.13 ms
Injector Offset:
V - ms
6 - 4.986
8 - 2.098
10 - 1.321
11 - 1.095
12 - .919
13 - .786
14 - .670
15 - .575
Last edited by passingpower; 08-17-2011 at 08:34 AM. Reason: Found the basic specs for Green Tops
Check before you consider tuning;
Is the MIL on? ANY leaks-vacuum, fluid or exhaust? Clogged filters? Old O2 or dirty MAF sensors? Dirty injectors, PCV or IAC passage? Correct the condition. Change the plugs & oil while you're at it. They need it anyway. Particular system giving you fits? Visually examine the related wiring first.
thanx passing power... i've gone through that stuff, before but the car was running so lean that i figured it couldn't have been right. thanx again
2001 3.8 v6 camaro, T5, ford 42lb green top injectors, grand national .63 a/r turbo. 8psi. stock motor, ngk tr6 plugs (one step colder) 91 octane.
2001 4.3 zr2 s10. daily driver, 31" tires, 4x4, cat! and exhaust. looking for mpg.
It'll be correct alright. The fuel calc uses Bernoullis flow equation. The same one ALL professional engine calibrators use. It will yield THE MOST accurate fuel model possible. That's with the possible exception of flowing and matching each of your injectors on a flow bench set up to match your rail pressure EXACTLY. The fuel calc is not only cheaper, it'll set you up quicker than "divide this flow by that flow to get a ratio and scale the IFR" 'cause after that you get to tweak and tweak and tweak. Even then your IFR is FUBAR! If you then turn around and MAF or VE tune, those tables will be FUBAR too.
Check before you consider tuning;
Is the MIL on? ANY leaks-vacuum, fluid or exhaust? Clogged filters? Old O2 or dirty MAF sensors? Dirty injectors, PCV or IAC passage? Correct the condition. Change the plugs & oil while you're at it. They need it anyway. Particular system giving you fits? Visually examine the related wiring first.
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