Very basic injector question. . .
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Cross-Country
Joined: Aug 1999
Posts: 63
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From: Eastern NC
Very basic injector question. . .
Lets say hypotheticly you have an EFI system with 24 pound injectors. If you swaped them out for 48 pound injectors with no other mods would it deliver twice as much fuel as needed, or would it have the capacity to deliver two times the max amount delivered by the 24 pound injectors?
Thanks
JYS
Thanks
JYS
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Joined: Dec 2001
Posts: 22,436
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From: Louisville,Ky.
I you just changed the injectors, it would flood because the ECM is still using 24lb pulsewidth. The O2 sensors would try to compensate, but It would basically have to shut them down.
The ECM( or Mass-Air meter if you have one ) must be calibrated to whatever injector size that you run other than stock.
Jimmy
The ECM( or Mass-Air meter if you have one ) must be calibrated to whatever injector size that you run other than stock.
Jimmy
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Cross-Country
Joined: Aug 1999
Posts: 63
Likes: 0
From: Eastern NC
gotcha Jimmy, so if you wanted to say, retrofit a 5.0 EFI system onto a 351 stroked to 427 you could put larger injector in to try to maintain a simalar pulsewidth? Sorry, I don't know much about it, but I'm trying.
JYS
JYS
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Joined: Dec 1999
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From: Copley, OH
Nope. The larger engine would suck in way more air and the PCM would try to compensate by driving the injectors to max, then the O2 sensor would trim the whole mess back to maintain fuel-air ratio. It might run but i doubt it.
If you change injectors you MUST change your MAF to match and you SHOULD change/reprogram/re-chip you PCM.
If you change injectors you MUST change your MAF to match and you SHOULD change/reprogram/re-chip you PCM.
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
If you use a Mass Air set-up, you can go to a company like C&L performance and buy a mass-air meter that is calibrated for whatever sized injectors that you are going to run. They offer a larger 73mm and 76mm that will flow alot more air than the stock 55mm and will be correctly calibrated.
Jimmy
Jimmy
