Ok i have this problem for almost two years now and i just can't figure it out.
Car is a 87 turboII stock.
The things i have done to try to fix it:

proffesionally cleaned injectors
cleaned all grounds
new tps and adjusted correctly

What it does is once it hits 0 on the boost gauge i get a hesitation actually more like a bog this is probably at 1/2 throttle then it will finally start to boost and drive fine i can go 1/4 throttle and the hesitaion/bog won't be there but then again it isn't going into boost.So what is my problem here i just can't figure it out?

 

classic secondary injector staging hesitation. make sure your ecu has good grounds, and wiring to your secondary injectors is in good condition.

Pocketlogger also offers a mod to the stock ECU that eliminates this hesitation by switching the staging from boost-based (0 psi) to load based with teh RTEK series. It eliminated all my staging hesitation problems.. i too was fighting it for years, ever since i first got my TII

 

anybody else have a idea im going to recheck my grounds today and also check my injector clips also anything else i should do?

 

i think i found a boost leak i'll fix this also!

 

get the Rtek chip if nothing else works. You can get the Rtek 1.5 (it's like 100 bucks or something), that should have stumble elimination I think and will work for your stock injectors.

 

ok i found a boost leak and fixed it..it worked a little bit but i still have a bog but i found something else out...when i was putting everything back together i forgot to plug the pressure sensor back in and the car ran better without it there was no stumble at all what does this mean?