Well crap. I killed it. Fuel pump installed backwards. Help please.

[tateg]

The title says it all. Dumbass me installed the fuel pump backwards because it looked like the one I took out. I then read the directions (particularly the plug that said "this end toward filter")and learned that everything is reversed on this new pump. So all the electrical connection point toward the tank instead of the engine.

Now I have no fuel pressure. I'm sure it's because I was pushing all the gas and air back at the tank where the other pump is and it need priming. The pump is trying to pump since I can hear and feel it running. The in tank pump was working before. I tested it and there was gas moving.

What do I need to do to get everything primed and pumping again? Any suggestions are greatly appreciated.

[SVOeric]

I'm a little confused.
you have the electircal connection on backwards, or you have the pump itself upside down?

either way, fix the problem, and you can prime it by turning the key off and on about 8-10 times -- that should be enough to get fuel to the injectors.

[tateg]

I'm a little confused.
you have the electircal connection on backwards, or you have the pump itself upside down?

either way, fix the problem, and you can prime it by turning the key off and on about 8-10 times -- that should be enough to get fuel to the injectors.

I installed the pump backwardswhere it was pumping toward the gas tank (it's an '84 inline pump). I discovered my error and turned the pump around and now can't get any fuel pressure. I for sure had none before with it turned around. Just turning it on and off again is doing nothing. The pump hums but I'm getting no fuel.

A guy at the shop where I was working on it suggested that I'd have to do something to the return line to get it to prime since I pushed all the gas out of the lines and was fighting the intank pump when it was backwards.

[Pat_in_L.A.]

I see that you have an 84. The electrical terminals on the external pump face forward on the car. You probably have the positive and negative terminals reversed. The replacement pumps don't clearly mark which terminal is which. Just swap the wires and try again.

[tateg]

I see that you have an 84. The electrical terminals on the external pump face forward on the car. You probably have the positive and negative terminals reversed. The replacement pumps don't clearly mark which terminal is which. Just swap the wires and try again.

Ok, here's what I did. I looked at the label on the pump where it said "this end toward filter" but ignored it because it was the non-electrical terminal end (the terminal end was toward the filter on the old pump). I installed the pump and used a multimeter to check which wire off of the old pump was positive since they were not marked. I had the end with the terminals facing forward and hooked everything up. I turned the ignition on and off at least a couple of dozen times with no results. So I assumed that "They" were correct and the end that said "this end toward filter" really was the correct way, so I turned the pump around in the line. Now the terminal end is facing rearward.

So if I understand correctly, the terminals go forward regardless of what the parts literature said and I *now* have it in backward but originally it was correct.

[Pat_in_L.A.]

Once you have the pump installed with the terminals physically facing forward, try the ignition switch a few times. if pressure doesn't build, swap the wires and try again. Since both terminals on the pump are insulated, I fail to see how checking them with a multimeter would help you determine positive from negative terminals. If you installed the wires backwards, a DC motor would turn the wrong direction and try to blow into the gas tank. Good news is there are only two ways to try the wiring, and the pump is likely still OK.

Ask me how I know?
Been there, done that!

[tateg]

Once you have the pump installed with the terminals physically facing forward, try the ignition switch a few times. if pressure doesn't build, swap the wires and try again. Since both terminals on the pump are insulated, I fail to see how checking them with a multimeter would help you determine positive from negative terminals. If you installed the wires backwards, a DC motor would turn the wrong direction and try to blow into the gas tank. Good news is there are only two ways to try the wiring, and the pump is likely still OK.

Ask me how I know?
Been there, done that!

The terminals are insulated but they aren't inaccessible, they're just standard spade connectors on the old pump. While the wires were just hanging there I just used the MM to test which was which. The new pump had post terminals so I had to do some cutting and splicing with new connectors as well. After checking with the MM it was pretty obvious anyway; the black wire was ground and the kind of orange wire was positive. The new pump was well labeled with a "+" and a "-" so that it would be pretty hard to screw up if you know which wire is which.

Anyway, if sticking it in backwards for a while won't screw anything else up(like the intank pump) then I should be able to put it all back right on wednesday.

When both pumps are replaced at the same time, does it usually just reprime by turning the key a few times or is there something special that needs to be done because all the lines are empty?

Edit:
How come they don't label these things with the direction of fuel flow?

[tateg]

Yep, that's all there is to it with an in-tanlk pump (of any kind). The omly things that ever needed priming were those side-of-the-block diaphram pumps that had to suck ten feet through a steel hard line to feed the carb above. Sometimes they needed a little coaxing.

They do. Look at the fitting where the check valve is. Sometimes the pump body has a "===>" Flow arrow stamped on it also. Iirc, you got a Holley aftermarket FI pump and not a Bosch replacement, right?

No, I was considering the Holley aftermarket pump but since I already had a brand new Bosch I decided to install it and upgrade later if I needed more flow.

This Bosch has a padded sleeve around it so it would be difficult to see the body without removing the padding. It may have a flow direction somewhere on it. The old pump didn't have anything on it to indicate direction of flow.

Thanks for all the replies BTW.