What sized injectors? (4age nerds)

[ollie83]

Hi all, im about to get my 4age rebuilt and am seeking advice as to what size injectors i would need. The current setup is 272 cams, 11.2:1 compression, quad throttles. Thats about all i can think you'll need to know to determine what sized I would need.... obviously non turbo too.
Is there such thing as being too big? I have the stock 7mge ones still (i think) from my old cressida, which were green, and from what i can find should be 315cc, 42psi and 13.8ohms. It would be handy to use these as i already have them, but i dont know if it'd be overboard. Any advice?

[RT40Corona4AGTE]

no the 7M ones should be OK, go too big and you will have crappy idle, but since this isnt a boosted engine, I think you should have ample fuel by sticking with the 7M ones. For reference, 4AGZE ones are 365cc from memory, so the ones you have from the 7M should be ample.

I assume aftermarket ECU?

Hope that helped

[oldeskewltoy]

I'm running a set of RC320cc(nearly identical to Supra injectors volume wise) They are fine, and at least in my case (low ohm) I have no idle issues

[ollie83]

no the 7M ones should be OK, go too big and you will have crappy idle, but since this isnt a boosted engine, I think you should have ample fuel by sticking with the 7M ones. For reference, 4AGZE ones are 365cc from memory, so the ones you have from the 7M should be ample.

I assume aftermarket ECU?

Hope that helped

Yes, adaptronic. I dont know much about all this sort of thing, but I found that in regard to ohms, those 7m injectors are quite high compered to standard 4age ones. How does this effect the idle?

[Omegaman]

the 4age will need low impedience injectors. As mentioned 7mge are high at 13.8.

As top feed injectors come in single spray and multi spray. you'll have to check if the engine will run smoothly with either choice.
Also the plug type may vary (oval type and EV1 type)

some examples you may want to use top feed Denso type based on CC and ohms only.

- 365 cc, 2.9 ohms red/orange in colour
- 430cc, 2.9 ohms black used in 7mgte
- 295cc 2.7 ohms yellow used in 7mge
std 4age may be 210 cc 2.4 ohms blue, sounds like the same as 18rgeu injectors.

[beerhead]

I'd look for something from the post year 2000 parts bin. I really like how the late model denso 12 nozzle injectors atomise fuel. 2AZ are 375cc 3MZ are 250cc.

Idling problems are normally related to injector flow rates, not the impedance. The injectors will draw less current and take longer to open, so you'll find they may need a slightly longer duty cycle than a lower impedance injector to flow the same amount of fuel. The amount of fuel delivered will still be controllable. A mates 4AGTE idled perfect on 550cc RX7 injectors, so I really don't think you'll have any problems.

BTW you'll find that you'll need a resister pack to run low impedance injectors on an adaptronic too. Using them without a resister pack will most likely burn the transistors out of the ecu.

[ollie83]

Very good, thanks all for the replies. Much appreciated! I will have to do a bit more digging around, but at least this gives me much better understanding so i will be able chase down what i need.

[4AGEKE55]

Old Thread revival.

Has anyone used the 2AZ injectors on a 4AGE?

Wondering if they fit straight in. If not what modifications are needed?

Has anyone found any other injectors that fit in the last few years?