My '83 280ZX is surging/hesitating until it warms up. Even after it warms up, it feels like it's holding back a little. In general, it's running pretty good, just feels like something's not quite right.
In the past few months I've replaced the fuel regulator, O2 sensor, all the vacuum lines, fixed an injector leak, EGR valve, fuel filter, oil & oil filter, NGK plugs, and the dizzy has been rebuilt.
Any Idears?

 

i had a problem where my 79 would hesitate to start, it'd take a couple tries, then hang around 600 rpm and surges until it gets warmed up enough to run smooth. i changed the cold start valve and i noticed a huge difference
just an idea, good luck
jon

 

That's kinda where I was headed, but thought I'd see if anyone else had BTDT.

 

That sounds similar to what's going on with my car too. But I don't know if it's hurting anything leaving it the way it is.