severe cutting out.

so i bought this 87 supra, which has basically a rigged up turbo. its a ct26 but it was sent back and had a different impeller and was milled out. so 1) im driving and in 1st gear it revs just fine up to 6k. every gear after that it cuts out after 3k-3.5k and to regain acceleration i have to feather the gas pedal. 2) i was driving yesterday and after putting about 50 miles down, lost all power and cant rev past 2k. it sputters and bogs and blows black smoke. i noticed the downpipe had shimmied away from the turbo so i figured the o2 sensor was tripping out. i re-tightened the bolts and tried again and it did the same thing. little help anyone?

Hard to say. The black smoke could be the motor running rich. Do you have a boost/vac gauge hooked up? Check for intake leaks, and do a compression check.

What upgrades r done to the car?

well turns out im an idiot. the intake pipe from the intercooler to the turbo slipped off whenever the engine torques. nothin gorilla glue didnt fix. on the other hand, it still cuts out once it builds boost. and another problem has surfaced. it runs fine for about five minutes then slowly starts to over heat. only does this under load. thermostat changed, radiator changed, water pump is flowing, and system has been flushed HEAVILY twice. upgrades are as follows: 60-1 10 degree clip turbo good for 18 psi intercooler that is good for 2,200 cfm lexus air flow meter thats good for 21 psi 550 injectors that good for 550 horsepower stage 3 ACT clutch good for 500 horsepower Felpro head gasket and ARP head studs intrax springs and adjustable tokico struts brembo disc brakes toyota pads LSD rear end with 4.10 gears The original motor blew up (dickhead didnt check the oil and ran down to less than half a quart) so we got an N/A motor and put the turbo head on it. SO now its running 9:1.

Do you have a fuel cut overide?

Did you burp the cooling system?

no i dont and i spent a good 6 hours flushing the system

so my lack of focus has pulled through yet again. i had the polarity of the fans backwards so it was heatsoaking the radiator. im such an idiot

If you are not running a fuel cut overide the ECU will cut the fuel once pressure reaches about 12-14 psi.

well im only running 8-10 psi right now. the guy who i bought the car from called it a boost leak. but even if air was leaking out of something around the turbo the engine should be able to still push it right? also i notice that it smells like its running really rich.

A boost leak means that the air is leaking out of the intake. If it is leaking then the motor will run rich and rough.

ok so then i need to look for a boost leak. i may have narrowed it down to where it is.