Pete919

Key on engine off fuel psi goes to 44 then quickly goes down. If I turn the fuel pump back on then clamp the fuel, line it still drops. Same with the return line. The fsm states it should then be a leaking injector. Raise the rail, turn the key, no leaks. Vacuum line on the fpr is fuel free.
Any ideas?

antfarmer2

Your pulsater is leaking or someone put the wrong hose in it's place. Pull the pump and see it is just on top of the pump.

Pete919

Then the psi would have stopped dropping when I clamped one of the lines right? Anyway no pulsator (fuel line in its place), pretty new walbro pump and afpr.

antfarmer2

Was it the right fuel line that can be submerged and tight with no leaks? I can see you clamping off the return line. But how did you clamp off the fill line in two seconds did you have help?
If you used regular fuel line it is a mushy mess.

Pete919

Fuel line came with the pump. I turned the key then went and clamped the fuel line with locking pliers. Does it have to be clamped right when the key is turned?

antfarmer2

When you turn the key on with out starting the pump will run for 2 seconds how fast are you? Some pumps do not hold pressure like the factory did. Is it running good or are you just looking for problems?

Pete919

Pretty fast. Fuel pressure is probably around 40 when I clamp it but then continues to fall

antfarmer2

If you have the return line clamped then pressure it up and clamp the send line if the pressure drops then you have a leak in the line, filter, fpr or injectors.

Pete919

Just tried that. Psi spiked. I couldn't get the clamp off fast enough. Everything in the fsm points to injectors but I don't see them leaking.

PatternDayTrader

What is the actual driveability symptom ???

antfarmer2

he never answered me.

antfarmer2

Yes it will spike but did it hold?

Pete919

Fuel trims are in the 140's and I get a pretty strong gas smell after a drive. Figured I would check the pressure, thinking it might be a bit low. I was surprised to see it wasn't holding. It did last year when I replaced everything but the injectors.

PatternDayTrader

High fuel trim numbers mean the ecm is adding fuel. Put your finger in the tailpipe and see if there is heavy black soot. You probably have o2 sensors going bad. Regardless, if your injectors or an injector is leaking then you would see lower trim numbers since the ecm would subtract fuel (because some is already leaking into the intake port).

Its worth mentioning that winter blend fuel will cause higher than expected fuel trim numbers ....

Pete919

Tail pipes look ok. O2's are new and working. I figured the ECM was adding fuel because the pressure was maybe low. Can't figure out why it's not holding.

PatternDayTrader

and that's exactly what it would do to correct for any lean condition. So your right about that.

April 1st is the expected changeover date for winter/summer blend fuels at all domestic refiners ....