2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Do I need bigger injectors

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Old Dec 22, 2004 | 02:02 PM
  #1  
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Do I need bigger injectors

My injectors are leaky right now and I'm probably going to replace the primaries, is there a reason to get bigger primaries? Eventually, I might get an SAFC, right now, it's street-ported, full catback exhaust not many other mods.

This is for street use, maybe a little autocrossing, but mostly street and it's a daily driver. Would I benefit much from having larger primaries? Would it make my fuel mileage a LOT worse, or just a little bit?
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Old Dec 22, 2004 | 02:15 PM
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no.

Fuel economy would be worse and you would loose HP.
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Old Dec 22, 2004 | 02:29 PM
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i got a NA with full exhaust and intake, as well as a SAFC2

would a t2 fuel pump boost my performance???
or bigger injectors for that matter
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Old Dec 22, 2004 | 05:00 PM
  #4  
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Originally Posted by wozzoom
no.

Fuel economy would be worse and you would loose HP.
any reasoning behind this? Is it because I don't have enough mods to support, using efficiently, more fuel entering the system even if the SAFC is tuned to intake more fuel and air adjusting to the new injectors?
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Old Dec 22, 2004 | 05:18 PM
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no. you shouldn't need bigger injectors unless you go with forced induction or p-port.
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Old Dec 22, 2004 | 05:55 PM
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what about fuel pump????
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Old Dec 22, 2004 | 09:53 PM
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HAILERS
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From: FORT WORTH, TEXAS,USA
Originally Posted by foild
i got a NA with full exhaust and intake, as well as a SAFC2

would a t2 fuel pump boost my performance???
or bigger injectors for that matter

The absolute best thing you can do for yourself and the car, is buy a wideband 02 sensor from TechEdge. Then you'll see that what you WANT to do is remove fuel from a n/a. Not add fuel. Much less a higher flow fuel pump.

http://www.wbo2.com/
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Old Dec 22, 2004 | 09:54 PM
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Originally Posted by nataku
...is there a reason to get bigger primaries?
No, in fact there's no reason to change any of the injectors unless you plan on making a lot more power than stock (>250hp). More fuel does not make more power.

Eventually, I might get an SAFC...
If you get bigger injectors you should always get a fuel controller so they can be tuned properly, or you'll simply use lots of fuel and have less power. A fuel controller should be bought before or at the same time as bigger injectors, not after.

A fuel controller will allow you to lean out the very rich factory mixtures, which will increase power and reduce fuel consumption. Injectors do not need to be replaced until they start reaching 80-85% duty cycle at peak load.
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Old Dec 22, 2004 | 11:19 PM
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well.. lets not say all NA's run rich..
when i checked my AFRs with a wideband (i got full exhaust and intake.. no other mods) i was actually usually running lean.

around the 15.0 - 17.5 range

so i altured that to 13:1 and now it runs like a king
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Old Dec 23, 2004 | 01:08 AM
  #10  
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Originally Posted by foild
well.. lets not say all NA's run rich...
Unless something is broken or malfunctioning, all stock and mildy modded NA's run rich. Factory full-load mixtures are always conservatively rich, and FC's are no exception. I would suggest that you find out what was making yours run so lean and/or double-check that your A/F meter is accurate. What did you do to make it richer?
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Old Dec 23, 2004 | 12:50 PM
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thanks for all the info, that's exactly what I wanted to know!

My car doesn't run very rich either, I never smell gas or have any backfires, is the only way to actually check how lean it's running, an A/F meter?
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Old Dec 23, 2004 | 05:24 PM
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From: Grass valley, ca
Originally Posted by nataku
thanks for all the info, that's exactly what I wanted to know!

My car doesn't run very rich either, I never smell gas or have any backfires, is the only way to actually check how lean it's running, an A/F meter?
i would have it dyno tuned with a wideband o2 if you are worried about it
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