Need to Prime a New FI Fuel Pump?

[RRoller123]

80 FI 2L:

I just replaced all the rubber fuel lines in the car, and installed a new fuel pump and filter. All connections double checked for correct assembly. Pump runs fine and sounds normal.

I "T"-ed my FI fuel pressure gauge off the CSI, and now get no pressure at all up at the front when running the fuel pump. I let the pump run for maybe a minute.

I am wondering if I have to prime the pump? A minute should be well long enough to move any air along the supply and return lines?

Pete

[lglade]

I did all my hoses recently too and didn't prime my pump either. I just cranked the car for about ten seconds before giving the starter a brief rest. On about the third try it fired right up.

[RRoller123]

Hmmm.... Thanks. Gotta take another look and see what is going on there. Whacky.

[ORFORD2004]

Reverse the wire at the pump?????

[RRoller123]

No, they are different size ring terminals and can only go on one way. But that is a good possibility. I will check it all out tomorrow, just wanted to be sure that the pump is self priming. I am sure it is something very simple. Maybe like a bonehead I put the filter in backwards or something like that.

[divace73]

you shouldn't have to prime the pump, it should be lower than the tank and gravity is your friend in this case.

Where abouts did you put the T?

[klweimer]

When I replaced mine recently, I hooked everything up, turned the ignition key to ON, popped the black cover off the AFM and pushed the silver arm off the stop to start the fuel pump. With the car off it was easy to hear the pump start pulling gas from the tank and pushing it up to the rail. You can even hear it start to break over the relief valve. I would say I ran the pump like this for maybe a minute to get to where the sound of the system became unchanging. Car fired right up after that.
Kirk

[RRoller123]

you shouldn't have to prime the pump, it should be lower than the tank and gravity is your friend in this case.

Where abouts did you put the T?

Pressure gauge at the CSI. I think I need to put more fuel in the tank to get the pump to be able to coax it up over the loop over the axle.

p.s. (I never use the vacuum to relieve pressure, just wrap a rag around the hose at the CSI and carefully pull it off. A little gas will spray if you are not careful. Battery disconnected, no smoking, the usual precautions.)

[micbrody]

I recently went through similar thing. I was having quite random, intermittent starting issues. Ruled out everything except fuel system.
I went to autozone and borrowed fuel pressure gauge and tee it off CSI . I sometimes got readings of 28-38. Thinking everything was fine, I decided to replace all the original fuel injection lines. I reconnected and primed fuel rail (as described by previous poster....opening AFM flap and ignition in RUN.) To my dismay, I had no pressure showing up. I theorized that CSI line was a dead end to CSI injector, so air would be trapped there until CSI fired a lot . I disconnected CSI and had fuel line to CSI go to tubing leading to a gas tank. I started fuel pump and "purged" air.....seemed to pump fine. I reconnected and again energized fuel pump.........no pressure reading??!!!!?!?!!?!
I'll just cut to the end of story: my pump was able to push fuel; but not at a high pressure. I replaced pump; everything worked great (including starting ).
So the take home message from this long boring story: MAYBE you need to purge air out of the dead end limb of CSI fuel line; or your new pump is not working (maybe hooked up wrong?, broken? Clogged? Pump backwards ?

[narfire]

me thinks wires are reversed....

[RRoller123]

Wires/terminals are marked for polarity and the ring terminals are different sizes. It is Hooked up correctly. (Actually it can't be hooked up incorrectly, the smaller ring terminal will not fit on the larger terminal.) But maybe it is internally wrong I suppose I could pull the intake line and make sure that there is suction at that side.

[RRoller123]

Never mind, I am a complete, utter, absolute bonehead. Soldered the wrong ring terminal to the wrong wire. Narfire is correct.

Checked the polarity, looked at the post markings, looked at the post sizes, then picked up and soldered the wrong ring terminal.

(anyway, I will always admit a stoopid mistake.... )

On a related question, the 2-way valve in the vent system was plugged up and I cleaned it repeatedly with carb cleaner, WD40, etc and got it to flow both ways, BUT there is a significantly higher pressure required when the flow is from the fuel tank to the engine (flows while filling up, vented out through and charging charcoal canister cap) than when going from the engine back to the tank (flushing the charcoal canister, make-up air). Someone mentioned that it should flow pretty easily, and roughly the same, in both directions? The "LOW" direction on mine is very easy, the "HIGH" requires quite a bit of pressure to get it to flow through.

Anyone know the correct operation of this thing?

Pete

[76was124]

Ha, funny, I was about to be the third person to tell you the wiring was backwards....and yes even if you have the factory spade terminals which are two different sizes, you can put them on backwards...yes I know for the obvious reason of having done it.

Regarding the two way valve. It does trip at different pressures one way vs the other. Not sure if it's based on pressure, or more related to two different sizes of the openings one way vs the other for air flow volume reasons. It makes sense I guess if you think of the difference in air volume flowing in when the engine is running vs the amount of air displaced by fuel expansion in the tank after filling up with 45 degree fuel.

See my first of two posts on this thread page http://www.fiatspider.com/f15/viewtopic ... y&start=45

[RRoller123]

Thanks, that makes sense and I think cleaning it made it function correctly. Fired up the pump and the fuel pressure at the rail is perfect now!