all right i've grounded almost ever thing . so i'm to the pressure sensor now and i've been looking for AWHILE now through all this threads but i dont really see anything cause evryone talk bout 4 wires well i have 5 (2brown/black,1 brown/white,1black/white,1brown/red ) which wire is it i came across another thread but they guy figured it out but didnt saywhich one.this is on a 87 thanks

 

*Sigh*

Do me a favor before you add that pressure sensor ground. Get to the ECU and find your ground wires (they're all black). Small plug, top row, 2nd one from left is one. Small plug, top row, very right one is another. Middle plug, top row, 2nd from right is the third.

Grab a meter, set it to ohms, and make sure you have a good "0" ohms when the leads are shorted together. Now put the black lead to a good bare metal chassis ground nearby (I use the nearby nuts sticking up), and put the red lead on each of the 3 pins I just mentioned. Sometimes putting a piece of small wire in the back of the pin and then putting the meter lead on that wire helps (paper clip bent to shape should work).

NOW, if you get 0 ohms (or damn near 0, like .1) for each of the three pins to ground, you DO NOT need to ground that boost sensor. You'll be doing more harm than good if you do...

 

get your injectors checked out, it solved my problem 100%