I get a hiccup or hesitation at around 6-7k under full throttle and full load, it happens in 2-3-4. 91/n/a true duals tii fuel pump s-afc coneair. S-AFC didn't seem to help, maybe made it worse?

Fuel filter is pretty new, don't know about injectors. And fuel pump was recently bought off of someone.

 

n/a's will not really lean out bad unless you have your SAFC tuned really bad .. they run pretty rich all the time.. no worries you arent leaning out.. maybe time for a tune up new plugs wires oil change.....

 

At around 6-7k under full throttle and full load your FI's are relyied on more then ever. I'll tell you that machine cleaning your 12 yr old Injectors, especially for the first time, will yield you Impressive results. It's like upgrading your Injectors but not. They are running the way their suppossed too.

Another thing I did when I swapped out Fuel Pumps Is flush out my gas tank. I used a shop vac to suck out all the little gas I had left In there. Than poured 2L of Isopropal alchol, sucked It up, repeated than done. Their was quite abit of sediment In my Gas Tank.

 

Another good idea is the addition of a quart of methyl hydrate to a full tank after every winter or so. It joins with water molecules, and allows it be injected and burnt. Great for cleaning mositure out of the fuel system. It's sold at auto parts stores, or paint stores. This is all that gas line antifreeze is, except you pay a lot more for mark-up on gas line antifreeze.

 

Extra grounds won't do harm either.

 

I have the same problem at 7800rpm right now on a heavily street ported motor with stock fuel system and a slightly raised fuel pressure. Use to lean miss at 7400 before raising the pressure. Halmeter showed/shows major lean condition. I'm too broke to do any of the other mods yet, but would like some ideas on how to better feed my car at higher than stock rpms.

 

hmm funny cause i too have the same damn problem and im running richer than most because i turned my rich lean screw to about halfway from normal and rich ????

 

I suffered the same problem. It was caused my the ECU retarding timing just before redline. I had a cone flter right on the AFM, with no head shielding or anything. It turns out my intake temps were so high the ECU was retarding the timing a LOT. Advancing my timing made it less noticable, but it was always still there, and I had to run 93 octane. Since then, I have moved my air filter to in front of my radiator, and turned my timing back a few degrees. My intake charge is MUCH cooler now, and Im running a few degrees advance on the timing, and using 89 octane. No hesitation anymore.