Ok here is the situation;

-F22 block\w f20 head swap (f20 cams) F20 ECU

-Apexi V-AFC piggy back

-J's Header & T1RT header back exh.

-J's Racing Tsuchinoko intake

-Walbro 255 fuel pump

-RC 440cc injectors



I was using a fuel pressure regulator\w stock injectors but somehow the fpr broke when i installed the 440cc's so i go with a brand new one but the problem was still there?!

The problem was engine hasitates at partial throttle and it was lean (afr 15-16) and it cannot be corrected with V-AFC so i thought the broken fpr also broke the fuel pump as if the stock pump cannot pump at high pressures so i replace the stcok pump with walbro 255 whising to solve the problem but i couldn't get what i expect the problem was still remaining.

Btw when i was using the stcok injectors with aftermarket fpr (46-55psi) my afr was 12-12.5 before vtec and 13-13.5 after vtec and i was pretty happy about that all the problems started after i installed the 440cc's

Today i replaced the RC440's with the stock injectors and engine is happy about it like never before

I think stock ECU cannot control any injectors over stock , i have the exact same problem when i installed the e-manage ultimate but i don't know the reason for that but it was exactly the same problem but i was using the stock injectors that time so i cannot figure out the solution for that either.( i installed the e-manage with frog harness so no false cable in the ecu diagram)

Now i have walbro255 fuel pump, fpr ( 48psi ) stock injectors and still have a 15 afr at WOT

Please guy help me about this or i'll go crazy

 

[QUOTE=bahadir,Jan 2 2007, 12:06 AM] Ok here is the situation;

-F22 block\w f20 head swap (f20 cams) F20 ECU

-Apexi V-AFC piggy back

-J's Header & T1RT header back exh.

-J's Racing Tsuchinoko intake

-Walbro 255 fuel pump

-RC 440cc injectors



I was using a fuel pressure regulator\w stock injectors but somehow the fpr broke when i installed the 440cc's so i go with a brand new one but the problem was still there?!

The problem was engine hasitates at partial throttle and it was lean (afr 15-16) and it cannot be corrected with V-AFC so i thought the broken fpr also broke the fuel pump as if the stock pump cannot pump at high pressures so i replace the stcok pump with walbro 255 whising to solve the problem but i couldn't get what i expect the problem was still remaining.

 

I don't think it's a vacuum leak problem cause engine idles very steady. Did your friend suffered idling problems or not ?

Thanks for the info btw

 

The stock ecu with a piggyback can handle oversize injectors just fine. When I had my UR turbo kit, I ran 600 cc injectors with the Greddy emanage. No problems. I would guess your problem is a tuning issue. In any case, I'm confused as to why the 440cc injectors. The stock injectors are good for over 300 whp. Do you expect to exceed that?

 

RC440 incase of emergency planning to sc my S

But it is nothing to do with tuning everything is stock now but the problem is still there

 

Everything stock except the fuel pump?

 

yes except fuel pump any suggestions ?

 

Actually hardly anything is stock.