Installed 440 injectors now have problems.

[TunerzEdge]

I just installed some 440 wrx injectors install was easy and had no problems.. but here is the thing. I took it out for a test drive and ran good at normal driving Then i went to step on the gas and it jump around like a bull ride wasnt fun... i so i drove back and popped the hood and check everything out made sure all the wires and plugs were in and installed in the right spot (even compared to the wifes MSP). and its all right. I thought it should run ok without EMS.. I am just wondering can i run it with out EMS? I have FMIC, CAI, exhaust, Just no EMS.. Do you think it could be that i dont have a Fuel Cut Defender?

[31R]

You will need some type of EMS. There are a few people using the DSM AFC and have custom maps tuned for 440's

[03MSP]

Bigger injectors will never work well without EMS.

[Earful]

This is true...


Bigger injectors will never work well without EMS.

[ChopstickHero]

Since they are bigger injectors, your ECU is spraying the wrong amount of fuel into your cylinders. You need EMS to tune them.

[slowmotionmsp]

Since they are bigger injectors, your ECU is spraying the wrong amount of fuel into your cylinders. You need EMS to tune them.

Does anyone know what size is the stock injectors, please?

By the way, I haven't seen many feeling the need to get bigger injectors. Under what mod situation does one need to consdier changing the stock injectors?

[ChopstickHero]

Does anyone know what size is the stock injectors, please?

By the way, I haven't seen many feeling the need to get bigger injectors. Under what mod situation does one need to consdier changing the stock injectors?
i believe the stock size is 280. so upgrading to 440 would be quite a big jump.

i think the stock injectors are fine as long as you are not maxing them out at high boost (meaning getting a proper EMS and tuning it). getting them is a safeguard to running out of fuel at the top end (going lean, detonation, boom!!)

[slowmotionmsp]

i believe the stock size is 280. so upgrading to 440 would be quite a big jump.

i think the stock injectors are fine as long as you are not maxing them out at high boost (meaning getting a proper EMS and tuning it). getting them is a safeguard to running out of fuel at the top end (going lean, detonation, boom!!)

Thanks!!

[protegeric]

The only time ull need bigger injectors is 14-15psi and up. They kinda suck a little cause tuning for coming into boost at different RPMs is wack. I have not tried this at all and dont know much about it, but the MPI tuner I think from MPNick gives you two extra injectors to add fuel only when you need it. With the 440s your car will run a little funky sometimes. Now, if all you`re going to do with the injectors in and the increased boost is go get a quarter mile time, then dyno tune it and go. It`s worth it. Otherwise, look for somethin else or stay under 14psi. The MPI tuner deal sounds good, but I dont know much about it right now.
And I believe that stock is 280cc also.


Does anyone know what size is the stock injectors, please?

By the way, I haven't seen many feeling the need to get bigger injectors. Under what mod situation does one need to consdier changing the stock injectors?

[Blitzd]

Ems + 440cc = Smooth Running

[mspHtown]

why would u ever put larger injectors in without any ems... makes no sense.

[TunerzEdge]

I dunno <---stupid I guess i took them out and sold them already .... thanks though

[Blitzd]

Decided which EMS to go with yet?

[JVJcivil]

I had 440cc injectors install while running the Greddy Emanage, and the car still ran like crap. The stock ECU is very smart and does not want to go into close loop circuit. Without this tuning is virtually impossible. Until you wire in an O2 Modifier which cuts stock ECU control beyond 2800-3100 rpm and certain boost level. Once this was installed the car was sweet. I was running 13 psi on the stock turbo and making about 245 whp. Surprisingly enough I have blown my motor and have decided to put the car back to stock. I have the O2 Modifier for sale in the FS thread under JVJcivil titled Mazdaspeed Performance parts for sale (Pics and Prices) check it out and let me know if you would be interested.