Would car even run if fuel pump polarity was reversed?
Thread Starter
Race Director
Joined: Sep 2001
Posts: 14,650
Likes: 750
From: NEwhere Ohio
Would car even run if fuel pump polarity was reversed?
RXP340 pump burnt out the intake bulkhead connector (Due to higher amps).
I replaced this with Racetronix BCWA-C44 which has higher rated terminals.
***However. Here is where the confusion lies.
It states that if using an RXP340 pump that the polarity needs reversed. It doesnt give any diagrams or further discussion on how to do so.
I imagine I could pull one of the weatherpack connectors out at the harness outside the tank if I had to..
I figure when I go to start this thing up, hopefully it will either run (if its polarity is correct), or not run (if wrong).
What I dont want to have happen is it runs half-arsed or 'runs' but is not 'right'.
I imagine if the fuel pump ran the wrong way it would try to pull full thru the return pipe.....
So whats CF's verdict on whether the car would 'run' with the polarity reversed ?
(I would call racetronix technical support but as many of you know its useless. They dont reply to emails and maybe 1 / 100 times somebody will pick up the phone. )
I replaced this with Racetronix BCWA-C44 which has higher rated terminals.
***However. Here is where the confusion lies.
It states that if using an RXP340 pump that the polarity needs reversed. It doesnt give any diagrams or further discussion on how to do so.
I imagine I could pull one of the weatherpack connectors out at the harness outside the tank if I had to..
I figure when I go to start this thing up, hopefully it will either run (if its polarity is correct), or not run (if wrong).
What I dont want to have happen is it runs half-arsed or 'runs' but is not 'right'.
I imagine if the fuel pump ran the wrong way it would try to pull full thru the return pipe.....
So whats CF's verdict on whether the car would 'run' with the polarity reversed ?
(I would call racetronix technical support but as many of you know its useless. They dont reply to emails and maybe 1 / 100 times somebody will pick up the phone. )
Drifting
Joined: Sep 2022
Posts: 1,428
Likes: 376
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
All other things equal, if the pump is pushing fuel pressure to the rail the car will run.
Reversing polarity on the pump itself will make it run backwards BUT - the pump you have is aftermarket - maybe it is simply wired to where the connector is just backwards to the stock one.
Reversing polarity on the pump itself will make it run backwards BUT - the pump you have is aftermarket - maybe it is simply wired to where the connector is just backwards to the stock one.
Thread Starter
Race Director
Joined: Sep 2001
Posts: 14,650
Likes: 750
From: NEwhere Ohio
Drifting
Joined: Jun 2013
Posts: 1,955
Likes: 340
From: Shell Point (Crawfordville) Florida
Before installing it in the fuel tank, why don't you just put it in a bucket of something and energize it with 12V and see if it pumps. If not, reverse the polarity and try it again. You'll figure it out and see for yourself.
Racer
Joined: Mar 2025
Posts: 485
Likes: 232
its not a dead head system. Its a loop with feed and return lines.
the return pipe which could in theory become the feed pipe if it sucked fuel due to reverse motor direction
the return pipe which could in theory become the feed pipe if it sucked fuel due to reverse motor direction
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Thread Starter
Race Director
Joined: Sep 2001
Posts: 14,650
Likes: 750
From: NEwhere Ohio
there may also be a check valve in the rxp340 fuel pump also (unless it overpressurizes and bypasses it
somehow)
i started the car up and it ran, so hopefully i got it right
Melting Slicks
Joined: Oct 2001
Posts: 2,315
Likes: 109
From: Brandon Fl
By my personal experience it will not run wired backwards. I wasted 1/2 day checking everything else because I was sure I wired it right. Turned out I didn't. If I would have double checked myself I could have saved some time.