Keeps going LEAN!!!!!

[mrviper99]

1996 GTS has cam, heads, tubes, filters, headers, high flow cats,t&d rockers and VEC 1. This is the problem runs ok until I punch it. On the a/f meter as I take off from a stop the meter dances back and forth as I hit WOT in second the light jumps to red light LEAN for 2 seconds. Engine bogs down, shudders then a/f meter jumps to blue light Rich, car runs great for the rest of 2nd gear. Third gear same thing happens. Have my settings at -6 low +4 high this matches what is recommended for my mods. This has just real started the last week. Had at the dyno last week saw it on the sheet on every other pull. One pull great second pull, well lets just say a Ford Pinto could beat me. Help need some answers. Jeff

 

[GR8_ASP]

Does the lean condition occur on 1 bank or both? Could be fuel system (pump, filter, etc.) or injector related. Any codes or other symptoms?

 

[mrviper99]

Can"t realy tell if its just one side or both , No codes have been set yet. Checked fuel pressure yesterday was 55 psi from idle to high rev.

 

[Moundir]

is this condition new since the heads/cam install? Whose setup did you go with, and how much power did it make? I heard some heads/cam setups without any tuning do starve for fuel. Good luck.

 

[mrviper99]

Have had set up for a few years. Just had engine rebuilt at arrow they had no problem on engine dyno. Made 555 at arrow and 507 at the chassis dyno on the good runs. Just didn't have enough good runs to dial in the VEC 1. The Vec 1 is the newest thing with 3 months on it and very little driving on it till now.

 

[GR8_ASP]

Have you checked all the Vec 1 connections? I really don't know exactly how it works but believe it intercepts the MAP sensor output and modifies it. A shift in MAP reading could result in a loss of fuel (if it provided a higher absolute pressure voltage).