[jedibarnes]

Alright, I will just be driving along and the engine and car will just start hesitating and bucking...Usually only happens on acceleration. Also, it tends to do it more while it is cold. If i smash the gas in the car will go back to normal, or if i push the clutch back in it acts normal. Also this morning on my way to class it did the hesitating thing then made some lock Knocking/clacking sound. Thats what really has me worried. I have replaced the fuel filter, check the cold start valve, had the Fuel injectors cleaned by a mechanic, checked the air filter. It is a 82 280zx 2+2...Let me know if you can help. As always you all are the best...thank you..bye

 

[jedibarnes]

I have also replaced the spark plugs...thanks

 

[Roadman]

Hi jedibarnes------------If this problem happens under partial acceleration and not under full throttle, chances are that the vacuum advance is not working properly. You may have a leak in the hose from the intake manifold to the distributor, a bad vacuum canister (on the dist) or a dirty, rusted and corroded advance plate. The plate can be accessed by dismantling the distributor. Clean and lubricate the plate. Replace any of the ball bearings that may have come loose from the carrier that rides on the plate. You can determine if the vacuum canister is operational by applying vacuum to the hose while watching for movement from the vacuum advance arm inside the distributor. The canister should also hold vacuum when the hose is plugged. Hope this helps.

Roadman

 

[Ron Diederich]

My 75 had the same problem. Turned out there was rust inside the gas tank.Is there a drain plug on your tank?. If so why not just unscrew it and have a little gas run into a coffee can or something then check for particles. Mine looked like I hit the ole' rust nugget pay dirt.
Ron

 

[hotroder]

I would check the dist cap for moisture and the plug wires for
arcing (high resistance)