my fuel pump or electrical?

[slideways412]

i just recently changed my clutch and now my speedometer doesnt work and sometimes in 3rd and 4th at 4k rpm's my car cuts off my fuel like i maxed it out then when it drops down to 3k it spits it back in. like my cars confused and thinks its top speed.. i dunno any ideas?

[nissan_star]

sounds exactly like my problem a few weeks ago. I bought a walbro 255lph fuel pump and viola! my car runs better then ever before, maybe a little rich but not a big deal.