derekderek

iTrader: (21)

My car is a 96 z28. It has never started on the first try. It has always taking two to three trys to get it to start. If I prime the system 3 times then crank it starts right up. So I figured maybe my fuel filter was clogged changed it still the same. Well I finally got tired of it and hooked up a fuel pressure guage. On the first prime no pressure is built what so ever!! The second prime I get 40 psi for maybe a second or two then it drops to 15-10 then eventually drops to 0psi. This is all within 5-10 seconds of priming. When started it holds pressure fine at 41psi and when I pull the vacuum hose off the FPR it jumps 4-6 psi like it should. I was wondering if there is a check valve in the tank or somewhere in the fuel line? Because I think the fuel is draining back in the tank. Any thoughts on this would be greatly appreciated.

Derek

96slow6

Well there are a few things it could be, none easy to figure out. Well its not that hard either. I am going to throw a dart in the dark, but it makes sense. Were the pump hooks to the fuel line its connected by a rubber hose (or it is on a walbro) that can go bad and allow it to leak back. Or it could be the pump is allowing it to backflow through it. I have seen both. Swapping out the regulator would be an easier place to start but i dont think that it is your problem.

derekderek

iTrader: (21)

Well I did some searching and finally found somethings that might help me. Like you said the pump might be letting it drain back in I guess there is a ball bearing in the pump that is suppose to keep it from draining back in. Well I have a Walbro Just been lazy to put it in so I guess I will do it this weekend see what that does. Thanks for the help

96slow6

Check the connection line that i was talking about some kits came with the SAE J30R9 if it did then you need to get the r10 line from an auto parts store. The r9 has been known to get eaten by newer gas additives.

derekderek

iTrader: (21)

Well the new pump fixed my problem! It has held 43 psi for 1 hr so far. The old hose was pretty brittle to. I did it with out the bucket for those wondering I know there is anogther thread on it. Well thanks for the help.



Derek