(Already searched the archives, and didn't find a problems similar to mine...)



Ok, the car is an S4 TII with Rtek 1.7, 550s/720's, Walbro 255, TB mod, no emmisions, top mount, and running stock boost.


I was trying to lower the idle, since it was a bit high, and for a while, drove it around with no problems.





Recently, and this first started happening while driving regularly on the freeway, I notice a VERY OBVIOUS bog/hesitation when I press the throttle all the way down, very suddenly.

The engine won't completely die, but it also won't rev past 2000rpms (not under load).


Got new spark plugs, and the same thing happens.



I can only get to higher rpm's if I'm VERY gradual/slow on the throttle, but even then it seems like it's misfiring and and the powerband is not smooth.






I know this could be any number of things...

Grounds?
TPS?
Vaccuum leak?
Fuel pump?
Plug wires?




Any ideas will help, thanks in advance...

 

still struggling...


checked AMF, TPS, and air temp sensor, with a Digital Multi-Meter...everything looks good...



changed plug wires, and still hesitating at wide open throttle.






help please...I'ma cry.

 

also...tried vise-gripping fuel return line closed, in order to possibly bump-up fuel pressure...same ****.