1996 nissan pick up runnig rough

[pablo911]

hi there, i need some help, this truck has this problem, at first looks like a simple misfire but all the ignition parts are new, the compression is even in all 4 cyls 150psi, i replace the distribitor complete, and nothing, now if i disconnect the maf sensor it runs great, no more roughnees, and i replace the maf sensor with a oem one and still the same thing, i already check the wiring harness, and continiuty,and is in order, also the fuel pressure and regulator were check ok, please if someone can help me let me know. thanks

[zanegrey]

check the vacumn..

also check the valve b4 the egr for proper function...