Alright i got a problem i think its fuel but im not a mechanic. Ok when i am driving my 1990 300zxNA stick, ill be driving and it will be running smooth and then all of a sudden it will studder and start to run rough and starts making a puddering sound. I loose power but it is drivable still it will do 80 mph but it doesnt seem to have the same power as when it is running smooth some times it will just jerk and then it will go back to normal. It normally happens after i drive somewhere and then turn off the engine for a bit and when i get back in thats when it does it. Does anyone have anyideas?

 

check your power transistor unit sub harness, just replaced mine. my car hesitated and stumbled on idle and up to 2000 rpm or so. and the whole car shaked at idle. looked over lots of things, but seems like that was the problem. my sub harness had a lot of green corrosion in it and tried to clean it and it ran better but not like it should have, just replaced and seems to be running a lot better. id look for corrosion in all connectors first, since problem is intermittent and then look for vacuum leaks and do the o2 sensor test with the ecu.