No fuel pump......

[Choochoochoo]

Just did the swap to the walbro 255, followed the instructions as per mc2racing website, pump isn't turning on. I've tried swapping relays, nothing.. I wired the pump directly to a switch and it works, but the car won't start.. as it sits now I have it all wired back into the original harness the way mc2racing instructs, and still no pump..... any ideas?

[jkxr4ti]

Is it possible you popped a fuse or tripped the inertia switch while you were back there wiring?

[Matt01]

follow the 12V till no more 12V

[Choochoochoo]

The inertia switch was removed quite some time ago because it was causing problems, so i know that isnt causing it. The fuse for the pump looks good, in fact, they all look good, except the hazard light fuse... while checking the relay, i did some probing and found that im not getting any power to the relay... can i jump it from the battery to at least get the car going?

[merk23literturbo]

http://www.angelfire.com/pa3/lyzcoinc/fuelpump.html

[Ed Lijewski]

[Choochoochoo]

Just tried to bypass the relay, nothing.... im really at a total loss here..... the only thing i can think of is some bad wiring somewhere.. are there anygrounds specific to the fuel pump? I know the wiring is good on the back half, at first i had the pump directly wired to a switch and it worked just fine, but the car wouldnt start. Now, using the factory wiring i got nothing. Just a dead paperweight....

[merkurdriver]

Check the main relay to the ECU - right next to the ECU under the glovebox.

[Choochoochoo]

Im pretty sure i already replaced that one. I suppose i can always double check it anyway, maybe see if i can find a legit motorcraft one for it.

[Choochoochoo]

So, i have no pwer at the fuse or relay for the fuel pump. Where does the power that feeds those come from?

[merkurdriver]

So, i have no pwer at the fuse or relay for the fuel pump. Where does the power that feeds those come from?

ECU tells the fuel pump to run - thats why I suggested the ECU relay down by the ECU.
(Otherwise I would say check the inertia switch, but you said that has already been bypassed.)

[Choochoochoo]

I must be thinking of the ignition relay, is the ecu relay the big black one thats tucked way up there? And if so, how do i go about testing it? Im not really great with electronics, this is fairly new teritory for me... good learning experience though..

[Ed Lijewski]

I'd look elsewhere first for the problen. Prior to the pump swap it's implicit that the engine started normally; after the install and new wiring connections it doesn't. I'd refocus on your install and new wiring/connections.

One known weak point is/are the female contact prongs for the relay power-to-fuel-pump msle prong. See photo I posted above. The female contacts weaken over time and even sink into the fuse/relay box. (Use a magnifying glas if necessary to take a look there.)

YMMV

[Choochoochoo]

The female connections are good, they actually look pretty clean, and the fuel pump relay has the tightest connection of any in the box.. im guessing somebody before me already had that problem and fixed it.. i can see all the connections rather clearly when the relay is removed.

[Ed Lijewski]

Female connections have to be......tight, snug at least.

YMMV