vc10786 Posted January 22, 2021 Share Posted January 22, 2021 (edited) I am working on a 1991 EJ22E engine and the car was left sitting for 10+ years. Sadly the owner left it sitting without draining out the fuel, and now I am trying to clean out essentially molasses from the fuel system(dark brown syrupy nasty old gasoline). The fuel pump is a gummed-up goner, but the fuel lines cleaned out okay, and now I am trying to get the fuel rail on top the engine cleaned out. I disconnected the fuel hoses and tried gravity-running a funnel full of fresh gas through the fuel rail, but it seems plugged up. So I attempted to clear it out with compressed air instead, and there seems to be a lot of back pressure. Some air comes out the other side, but it's definitely not free-flowing. Is the fuel rail supposed to be free-flowing, or is high pressure supposed to be required to get any flow through it? I already applied a vacuum pump to the FPR to simulate low manifold pressure, hoping to open the orifice and let the fresh fuel flow through the rail easier and out the return outlet, but it seems to have no effect. Still lots of back-pressure. Is the fuel rail plugged up? Or is it normal for it to be difficult to flow through? Thanks. Edited January 22, 2021 by vc10786 Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 22, 2021 Share Posted January 22, 2021 Unbolt and remove the FPR and try the air on the fuel rail. It should flow through easy. The system runs at 36 PSI using the vacuum. Without the vacuum the pressure is more like 40 something, I think. The fuel pump is capable of close to 80 to 100 psi, so it has a lot of push and a high flow rate. If the car is AWD, it has a saddle gas tank. The return hose goes into the tank and the fuel flows through a jet pump to siphon gas from the other side of the tank and bring it over to the side with the pump. In order to do that, it has to have a good flow out of the FPR. 1 Quote Link to comment Share on other sites More sharing options...
nvu Posted January 22, 2021 Share Posted January 22, 2021 It's not a freeflowing design, but you can take off the farthest injector to flush it. Use carb cleaner to let it dissolve. At this point just assume your injectors are clogged and look into backflushing them. There are lots of videos on how to do this. Quote Link to comment Share on other sites More sharing options...
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