I haven't had the car out for a couple of weeks, and today it ran real rough. It is sputtering like mad under acceleration. Looked at the fuel pressure, under idle, and the needle was "flickering". It was going between 30 - 40 #'s very rapidly. Any ideas? Service manual not at home.

 

P.S. Recently changed injectors. It ran fine since then though.

 

I was having some tuning trouble that I attributed to the fuel pump, so I changed it out for a aeromotive pump. My needle was flickering like you describe, but I thought it was because of engine vibration. After I changed out the pump, no more flickering in the needle.

Do you have an AFPR? Try turning the pressure down and see if it stabilizes. Gotta do it with the engine idling though, so make sure you don't lean it out so far it knocks.

 

Thanks. No AFPR, its the stock one. Also, I haven't been able to hold pressure after shut down. It hasn't been a problem, other than a little longer cranking time.

 

Mine did the same thing and it turned out to be the pulsator in the fuel tank.

 

If your losing pressure after shutdown their is definately a fuel leak somewhere. The pulsator could definately be a possibility. They were installed to reduce the noise made from the fuel pump. The problem is you have to drop the whole gas tank to ge to it. I would check to make sure the diaphragm in the fuel pressure regulator isint cracked. If its cracked you would see fuel in the vacuume line running from the the FPR to the plenum. If it has fuel in it you'll have to replace the diaphram. If it still loses pressure then crimp the feed line after shut down and see if the pressure holds. If it does you have a leak in your feed line and it's most likely the pulsator or a dying fuel pump. A word of advice if you do have to drop the tank: replace the pump and remove the pulsator and replace it with a small peice of hose. Dropping the tank is not something you wanna do twice.