ok a little back round. 88 gxl. series 5 j-spec turbo swap. s4 n/a comp. and harness.
under load and underboost it hesitates and back fires like a mother. i can drive the car fine out of boost but as soon as i put the pedal down it feels like it hits a wall. its like its getting to much fuel but i cant figure out the problem. this car is some much trouble but i can turn away. its like a love hate thing. i love her she hates me

 

might be a bad ground

 

how would a bad grond do that though

 

removed emissions? if so check the vacuum line on the throttle body, front and back. Change the plugs, I do it every oil change. Could also be the fuel pump failing at higher voltage.

 

emissions have been rremoved but i could have missed something( the intake mai. was off, i checked it three times but i still could have missed something), plugs and BRAND new and i will swap out my pump.

 

Did you cap and zip tie the closed line on the front and rear of the throttle body when you removed the emissions? Mine pop off under high boost sometimes.

 

It seems that you may have your timing too advance.

 

ill check those lines in the morning. cant be the timing. it was running perfect before i took the intake mani. off

 

their is also a hose that is normally like 6-8 inches long that you hook to the block, it connects to the bottom of the UIM. Its really hard to do it cause yo have to have the UIM on top of the block to connect it. I've seen a lot of people forget to connect that aswell.

 

that one is connected. i think that is the easiest one. the ones that are a pain are the three on the front behind the alt. what is the long bar the connects to the TB?

 

you have not explained your frankenstein setup fully. Is this basically an s5 shortblock with s4 wiring? either way, check TPS.

 

yes full s5 turbo swap with ALL s4 wiring