88 turbo II hesitation in 3rd and 4th gear pulls. Little lost the car is pretty much stock other the streetbeat 3inch downpipe and catback exhaust, bov valve air pump delete 255 walbaro pump. Recently replaced spark plugs fuel filter and some other maintenance stuff. It pulls fine at 7 to 8 psi in first and second doesnt break up at all wideband is all in rich when I go into third pulling psi goes up to 9 to 10 psi and starts to hesitate and even worse when pulling in forth it climbs to 11psi and cuts out. What I dont understand is its stock? No controler or anything to turn the boost up or down.. i do have some other issues whens its cold at first start it wants to die wont idle if I rev it up for 30 seconds it will idle fine around 1k then once the engine is hott it wont start its flooding out if I wait 30 mins it will start fine or if I push it and dump the clutch it starts fine. Im pretty sure I have a leaking injector there original 26 years old idk where to spend my money next lol need help.

 

Not really sure but i think you may be undergoing fuel cut when the boost gets to high for the stock ECU. Running that level of boost is too much for your car. I believe anything over 8 psi boost is not good and unhealthy for a stock set up engine.

 

Is the wastegate being over worked pushing over the stock 8 pounds and the ecu cutting fuel? Im not sure what makes it boost over the stock psi?

 

I understand the fuel cut from the ecu but theres nothing aftermarket on the car to change the boost why would it just make more boost im lost.. like I was saying it just has the 3inch downpipe catback 255 walbaro bov air pump delete and I make a turbo inlet tube. There isnt any boost controller

 

This is probably way to late to be of any help but, my guess would be your exhaust has increased your flow and boost to a point that the waste gate can't control it. You may also want to look at the waste gate actuator is, it even working. Get your injectors serviced and your boost under control before there is another one rotor post.
Dave