question about where correct fuel line go on my fuel rail 97 firebird 3.8

Looking at my factory service manual it shows the 5/16 fuel line as the feed line. and the 3/8th's return.

Basically it looks like the feed line goes straight into the fuel pressure regulator, anyone know for certain if this is correct?

I wouldn't think a 5/16th's line would be a feed line, but could this explain why when I shut my engine off I immediately loose fuel pressure? Or could the factory service manual be wrong or could the 3/8th's line really go to the 5/16th's line that leads to the fuel pressure regulator.

would the car even run if the lines were backwards?

I have new injectors which never leaked when fuel rail was pressurized so that isn't the cause of lost fuel pressure.

The 3/8 line should be from the FP, and into the rails directly.....the regulator comes off the rails in another spot, and it bleeds the fuel back to the top of the fuel tank through the smaller line....every FI setup I have ever seen is done this way....

1 way valve in pump kaput.

Weird that the 3/8 is returb, usually that's the feed and the 5/16 the return

Are you looking at them correctly? Hooked up in reverse the car will not run, you will not have fuel pressure

Twin_Turbo said:

1 way valve in pump kaput.

Weird that the 3/8 is returb, usually that's the feed and the 5/16 the return

Are you looking at them correctly? Hooked up in reverse the car will not run, you will not have fuel pressure

Click to expand...

Kind of thought that, but wasn't willing to go out on a limb to say that.....:clobbered:

Unless it is a printing mistake .... (2) is referred in the manual, you can see that line goes directly into the FPR. (3) is referred to as fuel supply line









This is how mine is, front line a 3/8th's rear a 5/16th's. I have not looked as to what line has fuel coming out of it. The check valve in my camaro was new along with pump as a new assembly and it bleeds down pressure just like this firebird (just not as fast)