Which injectors should I buy?

[starfish]

I'm not sure which injectors will be best for my set up.Ive heard that its better to go with bigger injectors with my turbo so I don't run too lean.If I get injectors alittle bigger than stock can I still use my stock ECU with out any thing having to be tuned.I have the walbro255lph HP.Blox FMU12:1,T3/T4 turbo.I saw some ACCEL injectors for like $175 and was wondering if they would work good with my motor.Motor is all stock accept for turbo,Fuel pump,FMU,Intercooler,sp wires,AEM fuego wideband kit,3" exaust,missing link,FCD.Right now car is running lean at idle.When driving on highway at 3000rpm wideband is between 14.7-15.3,at 5psi boost its around12.5-13.2

 

[rstare]

Whoever told you that was wrong. With a 12:1 FMU you can't use different sized injectors. You could switch over to an SFMU which would allow you to lower your idle/static fuel pressure and therefore use bigger injectors.
You could also use an SAFC and reduce the amount of fuel, which would allow you to use bigger injectors.
The ECU doesn't know when you change injectors, it always assumes the factory injectors are in use. So, if you switch from the 190cc (factory rated) stock fuel injectors, to 250cc injectors (just for an example) you're going to be getting much more fuel than you need. This is because the ECU still manages the PW's as if it were 190cc injectors.
If you just switch with either lowering you fuel pressure, or shortening the PW's you will run rich.
If you wish to switch to bigger injectors, use one of the methods I mentioned above.

 

[starfish]

Even with 200cc injectors will I still need to change to a SFMU.I bought the Blox 12:1 fmu thinking it would work up to 7psi boost,but it seems that I'm not getting enough fuel under boost.Could it be because my fuel pump is walbro 255lph(NOT HIGH PRESSURE).I did order walbro 255HP a couple days ago.Basicly I was wonderin if I could use the 200cc Accel injectors without having to change my 12:1 FMU(because it is brand new).I had a S-AFC but I sold it because I was told that it wouldn't work with a 420A under boost.But maybe the low pressure walbro 255 is causing the whole issue?Fuel cut at 4500rpm,Lean at idle(17.1 to ---) on my wideband gauge.

 

[rstare]

You have to have the HP fuel pump in order for that setup to work.

 

[starfish]

Thanx again,I owe you one!

 

[97420aNT]

Even with 200cc injectors will I still need to change to a SFMU.I bought the Blox 12:1 fmu thinking it would work up to 7psi boost,but it seems that I'm not getting enough fuel under boost.Could it be because my fuel pump is walbro 255lph(NOT HIGH PRESSURE).I did order walbro 255HP a couple days ago.Basicly I was wonderin if I could use the 200cc Accel injectors without having to change my 12:1 FMU(because it is brand new).I had a S-AFC but I sold it because I was told that it wouldn't work with a 420A under boost.But maybe the low pressure walbro 255 is causing the whole issue?Fuel cut at 4500rpm,Lean at idle(17.1 to ---) on my wideband gauge.

I will let you know in about a week i just bought some 200cc injectors and i am going to put them in with just using a vortech 12:1 FMU and a wideband. Im pretty sure they will work it might idel a little rich but i still think it will run.