Nissan Repair: cannot maintain speed, nissan 240sx, optical pickup

Question
My 1992 nissan 240sx cannot maintain speed. i took it to get a smog chek, but the DINO test couldn't be complited because the computer detected a lost in speed for about 2 seconds and then it would go up again. the test couldn't be complited since the computer would restart the test every time this happen. the guy doing the smog doesnt know what could be causing this problem. I also found out that when i accelerate at about 6,000 rpm and then put it in neutral the rpm goes to 0 and the car turns off. by pressing the clutch and releasing it it turns back on. what could be causing this problem?

Answer
Joel,

I bet the distributor is going out and that is what causes the drop in speed as detected by the computer.  Check the distributor for signs of oil on the optical pickup.  But, that is what I have had go wrong, in the past, that caused your problem.