studderin problem

[87 boosted]

Ok guys i need some help, I have searched through this forum and cant figure it out. I have a 87 turbo t and am having problems with the motor studdering in the upper Rpm's it runs real good until it gets in the rpm's. I have changed the MAF, TPS,Crank senser,coil pack,igniton module,spark plugs, and just cant find the problem. As of right now i dont know much about the car but it is mostly stock with a precision turbo, big intercooler. I also have the boost set around 11psi. I am new to these cars and trying to learn so any advise will be taking. Also my friend was behind me and told me that when i would get in the throttle is would black smoke a little meaning it would be running rich but the plugs didnt show to be real rich.
Thanks guys,
Nick

 

[1quick6]

Do you have a fuel pressure gauge on it? It would be nice to know what the fuel pressure is at idle with the vacuum line off the regulator. I am taking a shot in the dark here, but most street chips like to see around 43psi.

 

[87 boosted]

with the vacuum line off it is around 47 pounds with line on it is about 40 pounds

 

[turbojd]

Lower the fuel pressure as was said above, start out with 43 lbs. with the line off and see how it runs.

 

[TurboV]

Lower the fuel pressure as was said above, start out with 43 lbs. with the line off and see how it runs.

X2 on lowering the fuel pressure. How old are the spark plug wires? Didnt see those were replaced in your post.

 

[TurboV]

Also.... Which chip is in the car? and do you have a scan-master to post some numbers?

 

[BIGPSI]

check the ring under the cam sensor,make sure it's tight. i just went thru that.

 

[87 boosted]

yes the plugs and wires have been replaced and the crank senser is new and tight. I will try and lowing the fuel pressure tomorrow and no i dont have a scan master. I am not sure of the chip i will check that tomorrow also and let u guys know what i find because i dont know the chips. thanks for helpin guys

 

[BIGPSI]

i said cam sensor,not crank sensor

 

[87 boosted]

O sorry about that well this morning i got in the car and it showed and check engine light and i the scan tool that i have showed a cam senser code. i cut the car off and cranked it back and it didnt come back on. Then later in the day it came back on an showed the same code and i cut the car off and cranked it back and it didnt come back until later in the night. So i guess i will get the money and replace the cam senser and see if that helps.
Thanks guy anymore info let me know