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Old 01-02-2016
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Fuel injectors question

I am going to replace my fuel injectors and i was told that if i don't use the right fuel injectors i can flood my engine with gas... Is this true? Cause i don't wanna buy fuel injectors if its gonna flood my engine. Also if need be how do i find out what are the right injectors for my truck?

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Old 01-02-2016
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No, wrong size injectors won't flood your engine, but will cause poor operation the first few times you start it cold and until it warms up and O2 sensors start to work.

Factory air/fuel mix for your engine is in computer's memory, computer uses this preset mix until engine gets warm enough for O2 sensors to work, 4 to 8 minutes.

After O2 sensors come on-line computer can fine tune the fuel injectors for best exhaust Oxygen levels.

Fuel added to intake by injectors is based on "open time"(pulse width), Computer "opens" a fuel injector for XX amount of time to get XX amount of fuel to flow in.
The amount of fuel that flows in is based on Fuel Pressure and Injectors size.
If you change either then Factory air/fuel mix will be off.
After engine/O2 sensors warm up then computer can adjust the open time of the injectors to get correct air/fuel mix, and it "remembers" this adjustment, it is called Long Term Fuel Trim(LTFT)
After a few Drive cycles(warm ups/cool downs) computer can apply the "learned" LTFT to cold starts and warmed up driving.

But if injectors are too small or too large then computer will also set a code and turn on Check engine light(CEL).
If LTFT is outside of a certain range, like -20 to +20, then computer will notify driver that there is a problem with expected calculations based on factory equipment being used.
Could be MAF sensor, Vacuum leak, fuel pressure, or........wrong injector size

3.0l had 2 different size injectors, gas only 3.0l engines used smaller size, Flex Fuel 3.0l needed larger size for ethanol use, computer program is different for both.

8th digit in the VIN will tell you which engine you have
V = Flex Fuel
U = Gas only
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