I have a 78 280z, when I start it it will run like crap like it is going to die and then idles fine, when I come to the first stop or stop sign the idle will go up and down from 1000 rpms to 500 rpms and after that it will run fine . Does anyone have any idea what would cause that. I thought it was an air leak but am not sure. Thanks

when my 75 did that it was an air leak. except mine was a big airleak and mine idled from 2500 to 500 constantly man that was annoying. so yeah check for air leaks and if that isnt it im not sure what else would cause it. anyway good luck

Water temp sensor, fuel pressure regulator, air regulator, etc. There are a number of things that could cause that type of idle problem on the FI cars, air leaks are just one of them. Go through the FI troubleshooting list in the FSM.