So i recently just took out the 350 TPI from my Iroc and droped in a fresh 350 and a HSR, the engine runs nicely and doens tseem to have any problems but when the pedals to the floor its like im only pressing it 1/4 to 1/3 of what it should be, it just plateaus and dont accelerate any further,
feels like the powers there but it just doenst wanna give it to me, also has the service engine light?

has a different came, injectors, i had scott hansen off this site burn a new chip for me for all the new parts ect.

last bit of info, i read the fuel psi should be around 40 but it seemed to run poorly around that so we droped it down to 25-26 just to get it down the street.

any ideas???

 

The injectors will not function well at 25-26psi. Minimum pressure for port injectors is 35psi. 40-50 is much better. Your engine is starving for fuel. You need to address this and diagnose the poor drivability.

 

so i cranked the PSI back up to 40 and it barley runs, it idles nicley at 25 so im pretty baffled right now, could a large vac leak cause something like this?

 

Vacuum leak will affect idle, not wide open throttle. At wide open throttle, most air comes in through the TB and vacuum leaks don't have as large an effect. What you likely have is a tuning issue. Your getting too much fuel at idle and not enough at WOT. That's why I dont like mail order tuning. The person doing the tuning needs to be with the car to verify that the tune actually works. 25psi on port injection just doesn't work period. The injectors need at least 35 psi to function properly. You need to keep your pressure where it belongs and figure out what's wrong with the tune.

Aside from the tune, some other things that can cause severe rich condition is a shorted O2 sensor or ruptured fuel pressure regulator diaphram. You might want to check those two things. If fuel comes out the regulator vacuum port, the diaphram is shot. If O2 voltage reads .005 and you know your car is running pig rich, the O2 sensor or circuit is shorted.

 

This is making me worried, as Scott Hansen also tuned my chip. My swap is a few weeks away from being complete, very worried now...
I agree with ASE doc, check your regulator.

 

Don't be worried. Just try it and see if it's okay. I have retuned my ACCEL DFI several times and am in the process of tuning it again since I added ram air and a high flow air lid. The only problem with burning chips is in order to change settings, you have to burn another chip. But it's not the end of the world. Use a scan tool to verify that the tune is the problem and then let Scott Hansen know. Im sure he'll help you with it.

I like my DFI. I just connect my laptop and open up the program. I can tune in the garage, or I can tune in the car with the laptop in the seat next to me. A wideband O2 sensor is nice to verify correct AFR.

 

the thing is that it runs nicely at the 25 psi which everyone ive spoken to is just odd and my areomotive FPR isnt even supposed to go lower then 30psi or something like that , so many things it could be , feeling quite overwhelmed, 60 grand into this car and 3 years and it doenst even work!

ive also got engine codes 41 and 42, dont have the list in front of me but if you guys ha^ppen to know them and see them as a possibility here let me know, thanks

 

Code 41
Cam Sensor (CAM) failure
Cylinder select error
Tach input error
Elec spark timing circuit- open or shorted to ground during engine run
Direct ignition system fault- bypass circuit open or shorted to ground
Ignition system fault - loss of 1x reference pulse signal

Code 42
Elec spark timing circuit - shorted or open
Direct ignition system fault - Bypass circuit open or shorted to ground during engine run
Fuel cutoff relay circuit - open or shorted to ground

so those are the 2 codes, goign to check the things you guys mentioned just thought id throw these out there to see if it yeilded any new ideas

 

now i also dont have a vaccume line hooked up to the FPR, its a areomotive one and i guess in the instructions it said to just leave the vac port open to atmosphere, didnt notice any fuel comeing out but sould that line be hooked up? i was told it was just for boosted vehicles so the FP rises with boost

 

Vacuum to the FPR is part of the factory fuel management. You can tune with it or without it but if the fuel or VE map was written with it, your engine will idle rich without it. It simply helps the ECM manage fuel trims at idle and under load by adjusting fuel pressure according to mainfold pressure.