marinno31

I have a 74 260 that will start and run great for about a half hour then it will start sounding like its on 5 cylinders, after it sits for awhile it fires right up and goes great again for about half hour,then all over again.. Does anybody know what is happening, im very frustrated.. It has the original flat top carbs.

Hi Can Anybody Tell Me Why My 260z Will Start And Run Excellant For 20 Min Or So And Then It Starts Sounding Like Its Running On 5 Cylinders. I Will Limp It Home And Then After It Sits For A While, Ill Go Back Out And It Fires Right Up And Sounds Normal, Then Ill Try It Again And Same Thing Runs Good For Awhile And Then Back To The 5 Cylinder Sound And Running Crappy.i Have All Original Carbs, That Seem To Run Excellant, Until The Car Is In Its 5 Cylinder Mode..