New intake manifold and injectors, now have a problem

[viper98885]

I have talked to a few of you via AIM about this problem, but I would like to get some other's opinions if possible.

I just installed a modified upper intake manifold from Nu-Tek with the LT1 throttle body on my 3.4L. When I did the installation, I also installed 19lb injectors. I adjusted the fuel pressure with my Holley AFPR to 42 psi with key on, engine off. It dropped about 3 psi when the engine was started. It idles fine, but when I accelerate, it seems like the best acceleration is at about 30% throttle and above that, it doesn't produce much power. Some have said that the pressure is still too high so I plan on playing with it a little tomorrow to try to tune it right, but I am looking for other options of what else I could check. I also plan on hooking my Scantool up to it because it did throw a SES light this afternoon and I would like to monitor the A/F ratio above the 30% throttle range.

Any opinions or suggestion would be greatly appreciated...I may change back to the stock injectors if I can't get the problem solved.

Thanks in advance!

[Tiago]

scan the SES, it may reveal another problem such as a bad TPS or something ...

[Fin]

What's normal fuel pressure for a stock 3.4L? I would play with the fuel pressure a bit to find what the car likes, you may either have to lean it out or richen it up some. Also, like Tiago said, find out about the SES light, and check your TPS, MAP, etc. for proper values.

[viper98885]

I still haven't scanned the PCM yet, but I did play with the fuel pressure a little. It helped to turn it down a bit. I will repost when I get the trouble codes.