No starting after fuel pump install

acr2002 · Post by **acr2002** » Sat Oct 30, 2010 9:08 am

I installed a Walbro fuel pump and now the will not start. I can hear the pump prime but I am assuming there is no fuel pressure for some reason. I feel like I installed it exactly like I took it out, but I don't know. I am starting to think the fuel pressure regulator is the culprit, but the car was running before the install. Is there any way to check the FPR to know it is working? The small wire harness clip that goes to it is broken, but it seems to be getting a fine connection.

Any ideas?

quicksilvr · Post by **quicksilvr** » Sat Oct 30, 2010 9:41 am

Have you checked everything closely to be sure there are no leaks forming since you've been trying to start it?

If there are no leaks and everything is pressurizing like it should, then you either have a faulty pump, or there is a bad connection somewhere now. I highly doubt the FPR is culprit...if it worked fine before, and all you did is disconnect it and reconnect it...nothing should have changed with the FPR.

Have you viewed this how-to writup on the fuel pump?

viewtopic.php?t=2658

acr2002 · Post by **acr2002** » Sat Oct 30, 2010 10:10 am

yeah, no leaks and that is the how to I used....

I really don't want to take the tank out again, but I don't think I have a choice.

NickKo · Post by **NickKo** » Sat Oct 30, 2010 12:45 pm

Does the pump hum when you first turn the key on ??

If not, check to make sure you have VOLTAGE reaching the connector at the tank.
If you ARE getting voltage at the connector, then I bet that the fuel pump is wired backwards, and flipping the leads at the pump itself, will fix it.

Let us know what you find.

- Nick

acr2002 · Post by **acr2002** » Sat Oct 30, 2010 3:58 pm

yeah I can hear the pump hum when I turn the key to "on"

I put the harness back together exactly like it was (I drew a diagram to make sure I did this right). I feel like a moron not being able to sucessfully install a fuel pump, I have done much more involved installs than this.

I won't have time to work on it this weekend, but I will update when I figure it out. Hopefully, it is just some dumb error on my part and can figure it out.

NickKo · Post by **NickKo** » Sat Oct 30, 2010 7:54 pm

acr2002 wrote:yeah I can hear the pump hum when I turn the key to "on"

So we know that current is getting to the pump.

What is your fuel pressure with the key left in the 'on' or 'run' position ?? Do you have a proper gauge to test it with ??
That is the next thing I would check.

- Nick

OB · Post by OB » Sat Oct 30, 2010 8:01 pm

Don't waste another minute before you check for pressure at the rail. If the pump does indeed prime with the key on, but you don't get pressure, it's possible that you have the polarity switched as stated above. If the pump receives power in the opposite direction, it will pump backwards as well. Not sure if this is even possible on these pumps, but it can be done in general.

If you end up having fuel pressure at the rail, then the problem is further down the line, either the rail or injectors. Also, have you verified spark?

acr2002 · Post by **acr2002** » Tue Nov 02, 2010 9:16 pm

I am an idiot. I took it back out and I DID wire the harness backwards. Kids, this is why you don't work on your car at 11 pm at night when you should be in bed. Re-wired it and it fired right up. Thanks for the help guys, 2gn.org comes through again.