problem with throttle - lean start off

[twinturbozxtacy]

ok so i got this new 2+2 turbo zx, and its all good minus one problem. ok so let me try to explain. first off no matter what rpm or speed it does this, even with the slightest touch of the throttle. i bought a new tps and set it to .45v and its perfect. so its when ever i start from a start, or when im cruising and then touch the gas pedal a tiny bit. like to go up hill or faster for a change in the speed limit. so what it does is go super lean, like to the point where it stumbles for a good 5 seconds or more. this happens at any speed, it doesnt matter if its from a start or at 60mph. but if i floor it, it wont stumble but it will read very lean, 13.5-15 on my afr gauge. but if i just gently hit the gas it stumbles and read beyond the lean limit on my afr gauge. the injectors are new, fuel pump is new, my only though is the maf but would a maf cause this? i though a maf would run like crap all over. if im stopped and take off like a maniac its all good though and afrs are good as well. im stumped and would like feedback if anyone has any. i can get a video if needed.

[Ziggy1621]

I had this happen once. It was the timing for me, so check your timing.

Also, does it change any between being color/warm?

[twinturbozxtacy]

i thought it was timing also, its dead on at 15btdc and the belt is new. i dont drive it when its cold but it idles the same just a tad richer on start up. im thinking its either the maf, or ecu. the tps is new, so are the injectors... ill make a video to help show what it is doing.

[nissanfreak12]

What kind of TPS did you get? I had one at autozone that didn't read right out of the box.

The other question is, is this a TT swap? 5 speed swap? I would also lean toward the MAF or ECU, maybe even the CTS. Another thing is to check is the opening of the butterflies, make sure they are clean, and so on.

[twinturbozxtacy]

i think tps was from autozone but it check out fine on my meter and voltage rises smoothly like it should. not the maf, i took a known good one from my friends zx and still the same. so im down to the ecu or fuel issue, possibly fpr? here is a quick vid, weird thing is that its always bouncing around(afr) its only steady when i cruise at a set speed. any pedal touching will cause it to go lean and stumble.
http://www.youtube.com/watch?v=8vAfnz4nWWE

[nissanfreak12]

Have you checked your O2 sensors? Vac/boost leak? How is the wiring harness? How old?

Hmm, maybe it could be FPR or ECU.

[twinturbozxtacy]

harness is new, no leaks, i pressurized the whole system. o2s are something to check i guess but would they cause that big of a diff on these cars.