Injector swap????

[midnightangel]

I have a 1989 240sx SOHC and I want to take out the stock injectors. I have access to anything I want off of all the nissans in a junkyard. Can I use the injectors from any other Nissan for this car?

Right now my car is turbo'd and I am pushing 80 PSI through the injectors. Seems to work just fine, but I don't like pounding that high of pressure through the lines and injectors all the time.

The reason a larger injector would be to lessen the constant pressure, while using my FMU to raise the pressure when needed.

I've heard about using 370cc injectors, but don't you have to get a different ECU or something?

What are the cc's in the stock injectors?

[slideways...]

stock sohc injectors are small. and top feed. this is a problem because so many fast nissans and fast cars in general use side feed. i have no idea what other cars use larger top feed injectors. any DOHC ka24 will have side feed, and those i know are 270cc. the SR20 injectors are 370cc. iirc 300zx TT injectors are 550cc but i could be wrong. nevertheless, they are all side feed.

my suggestion is contact RC engineering. they can make any injector style with any flow rate. and they are pretty smart guys.

[midnightangel]

I was reading about an hour ago and found out that the SOHC 240's are 275 and they recommend upping them to 370. No idea on the 370's????

I did put a set of 2002 Supra injectors in the car once..... Sitting still and reving it, spooled the turbo extremely well, but when I took off, it bogged really bad. Maybe I should try it again and turn the fuel pressure down to like 20 instead of 50. It might actually work.

I do understand that these cars run a High Impedance injector and those are High Imp and top feed. I'll swap them out tomorrow and post it if it works.

I do know that the ECU can't really handle larger injectors without an AFC, but I wonder, if turning down the pressure, would compensate.

I used to own a Mittsubishi Starion and a Chrysler Conquest TSI (both of which are same cars) Anyway, we could take a 1G Mass Air from an Eclipse, modify the plug, and use it in the starion and conquest. It improved turbo curve and you could pound the psi through it.

Do you know of a wiring diagram for our mass air on the 89 and what about a mass air to use. I want to experiment and figure it out so I can help give others some alternatives to buying a new ECU when turboing their SOHC 240.

Thanks

[mmcleo11]

Lower fuel pressure is a bad idea, it reduces fuel flow and importantly, reduces fuel atomisation as there is less pressure. The fuel sort of dribbles out...

Honestly, I would even look at keeping the stock injectors and increasing fuel pressure to 60psi for the equivalent of around 330cc of flow.

[midnightangel]

Here's the deal. I see what you are saying and it makes total sence. I should've thought of that. LOL. Anyway. I have stock injectors, after market adjustable FPR w/vacuum. I have the regulator set at 55psi at vacuum and at 0 vacuum it sits at 62. Under pressure I'm sure it raises to about 70 or more. But I tell you this. Even with the stock stuff, it only gets about 18 to 20 MPG on the highway. :-(