I just changed the plugs on my 83 280zx n/a due to flooded fouled plugs
now that I put the new ones on it starts but studders and sputters ,
Im thinking that it might be the fuel pump, or pressure regulator

need your feedback...

 

my feed back is put a pressure gage in the fuel ring and find out what is going on. why do people post without having the slightest idea of anything. YOU THINK!!! I think I am not a clairvoyant. well at least you got the year and n/a info

 

geeeee. thanks rogerz for smart *** comment... you'd think that if I knew what was wrong with it, I wouldn't post anything, thou thank you for your feedback.

 

Wow....I'm glad I haven't asked anything yet.

Brother J, I had that issue when I was deeply involved in classic Volvo cars. (the sputtering after a plug change, not the jackassery that seems to befall Zcar owners...the guys on the other Z forum are the same way...Volvo people are different, but that is another story...)
Anywayyyy...the sputtering happened to me twice. Here were my particular problems: While changing the plugs, I dropped one and it clanked its way down to the shop floor. I retrieved it and installed it. When I started the car, it ran like junk, so I eventually took the plugs back out and discovered the one I dropped hit the floor just right and closed the gap. The 2nd time, it was simply crossed wires. Inspect your wires from the distributor, to the plugs. Maybe there is a contact not snapped into place.
I'm new to 380zx, but well versed in classic Volvo, Volvo clubs and Volvo forums...if you have any tech questions, go talk to my crew at turbobricks. They love to teach what they know...tell'm StreetKing sent you. (And yes, before someone chimes in, I am aware of the differences between Japanese cars and Swedish cars...but all cars pretty much run the same way, for the same reasons.)