tbeaty4

Can anyone tell me the size of this nut and can anyone explain to me what the dashpot assembly is suppose to do?

I'll see what I can do. The guy I got the car from died like two months after I got it which was a couple years ago. I didnt start working on it till just a few weeks ago and I'm having a little trouble tracking down the mechanic who was supposed to have done the work. It also does not go into higher idle when its cold. It starts perfect but wont idle without giving it a little gas and runs rough until the engine warms up. probably has a bad water temp switch or air bypass valve. I'll read through the fuel injection manual some more and see what I can find.

through the exhaust, its fuel injected

I have a 75 280Z which supposedly had significant motor work done, the extent of which I do not know. It has custom 6-2-1 headers and what appeared to be new parts under the valve cover as there was very little to no signs of wear. I took off the valve cover and checked tappet clearance. I timed the car according to the factory spec. but it has a little backfire when the throttle is released especially at higher rpm's. I think it's out of time slightly but I can't remember which direction i should go to try n fix this. Timing? or should I look at other things as well?