Legacy fuel injector colors and flow rates?

[gnuman]

OK, I know that 90 and 91 had grey injectors, and my 92 up to 94 have red ones. I'm guessing that the color is a code for the flow rate of the injector. I'd like to know what the flow rates are for each color, and which ones my ECU (92, with red injectors) could trim easily. Also, would this give me much of a boost in power? what would be the cost WRT fuel milage?

[Legacy777]

The injector colors relate to the type of injector, not flow rate.

All 90-94 legacy injectors are rated at 270 cc/min.

Balanced & blue printed, they can flow around 280 cc/min

http://www.main.experiencetherave.com:8 ... orcalb.jpg

[gnuman]

thanks Josh! what kind of report was that? where should I go to get mine tested, if I were so inclined?

Also if standard is 270cc/min what is the max the ECU would be able to trim easily?
What would the advantages/disadvantages to upgrading to a higher flow rate?

[Legacy777]

www.rceng.com

With those injectors in my car, it can trim things after I have some run time and the ECU learns. I wouldn't want to go much larger on an n/a car.

Unless you have done MAJOR mods to the engine, I don't see any benefit to getting larger flow injectors. Getting them balanced however will be beneficial as it improves engine balance & performance

[gnuman]

I will likely not be doing any major mods to the car as they tend to comw with a price I'm unwilling to pay: reliability.

This car is rock solid and I'm not feeling any burning need for more power. It would be nice when I'm towing heavy loads, but that is not a burning need in an of itself. better struts is more important to me. something adjustable on the back (AGX) and a good general purpose (GR2) on the front. the front dynamics do not change much under a trailer load, but the back does. . . .

[gnuman]

Back on the original topic, though, what is the difference between the grey injectors on the 90 and 91 models, and the red ones on the 92-94? is it a better pattern perhaps?
and is it backwards compatable to the older cars?

[gnuman]

Oh, and this seems as good a place as any to express my deep gratitude for all the help you have given both to myself, and to so many others both here and on the USMB forums.

[Legacy777]

The 90-91 injectors are just different then the 92-94's.

The 90-91 MT's are ball nozzle types
The 90-91 AT's are pintle nozzle types

I don't recall what the 92-94's are. I'm sure Vikash knows though.

Not sure which injectors are "better" though, if any are better. Just different.

[vrg3]

92-94 non-turbo injectors are pintle type.

Any injector design is a tradeoff between things like opening time, atomization, longevity, and resistance to clogging. Ball-type and pintle-type injectors just make different compromises.

Because there's probably a difference in opening time, you're best off sticking with the type of injector your ECU was meant to be paired with.

And ideally, you wouldn't want the ECU to have to trim at all for them. There aren't any advantages to changing the flow rate unless you have other engine management problems that you're trying to mask.

It would be good, though, to have them all cleaned so they all have very similar flows. Or maybe it'd be a little bit better to give cylinder 4 an injector that flows slightly more than the others, since the design of our intake manifold gives cylinder 4 a little more air than the others.

[THAWA]

the 92-94 are pintle nozzle, but the style is different.