Won't Start after fuel pump replacement

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Jospina
Posts: 5
Joined: Sat Jan 30, 2021 11:37 pm
Your car is a: 1982 Spider

Won't Start after fuel pump replacement

Post by Jospina »

Hello all and thank you in advance,

So I got a '82 model which was starting but was stalling when driving. The fuel pump was making a really loud humming sound when turned on, so I decided to start my troubleshooting there by replacing it. Now that I changed the fuel pump the car won't start now. You can hear the new pump work and I also checked that the EFI is getting gas, not sure what the pressure is or why it won't start. Any tips?
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Won't Start after fuel pump replacement

Post by 18Fiatsandcounting »

Have the fuel lines from the gas tank to the fuel pump been replaced? If they are bad and there's an air leak, even a small one, the fuel pump will spin but it won't pump fuel up to the engine as it should. It's fairly common for fuel lines to go bad over the decades.

-Bryan
rridge
Posts: 162
Joined: Thu Aug 10, 2006 11:59 am
Your car is a: 1981 Turbo Spider

Re: Won't Start after fuel pump replacement

Post by rridge »

A loud FI fuel pump is working but working against a high flow restriction somewhere in the system. The usual reason is a plugged fuel filter.
Jospina
Posts: 5
Joined: Sat Jan 30, 2021 11:37 pm
Your car is a: 1982 Spider

Re: Won't Start after fuel pump replacement

Post by Jospina »

Thanks guys. It turns out it the new pump polarities were inverted. But I also replaced the fuel lines and the two filters. It starts right away now. :D
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Won't Start after fuel pump replacement

Post by 18Fiatsandcounting »

Glad you got it figured out, and thanks for letting us know!

-Bryan
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RRoller123
Patron 2020
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Posts: 8179
Joined: Sun Nov 13, 2011 2:04 pm
Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Won't Start after fuel pump replacement

Post by RRoller123 »

I did the same thing, green was always ground in my book, I didn't even think twice about it until the pump didn't run. LOL.
'80 FI Spider 2000
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'75 BMW R75/6
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2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
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