Electronics Need help wiring something up? Thinking of adding an electrical component to your car? Need help troubleshooting that wiring glitch?

How to disable only the fuel pump?

Thread Tools
 
Search this Thread
 
Old Mar 2, 2017 | 09:09 AM
  #1  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
How to disable only the fuel pump?

I want to run it on fuel injector cleaner through the rail (the Echlin kit). I need to disable only the fuel pump.

Any tips?

Last edited by Tootie Pang; Mar 2, 2017 at 09:16 AM.
Reply
Old Mar 2, 2017 | 10:06 AM
  #2  
kaos420's Avatar
Member
 
Joined: Aug 2008
Posts: 172
Likes: 16
Car: 88 gta
Engine: 5.8
Transmission: 700R4
Axle/Gears: 3.73 POSI
Re: How to disable only the fuel pump?

pull the fuse..
Reply
Old Mar 2, 2017 | 10:19 AM
  #3  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: How to disable only the fuel pump?

which fuse? That 20A inline?


Reply
Old Mar 2, 2017 | 11:04 AM
  #4  
OrangeBird's Avatar
Supreme Member
10 Year Member
Liked
Loved
Community Favorite
iTrader: (1)
 
Joined: Feb 2012
Posts: 3,939
Likes: 801
Car: 1989 Firebird
Re: How to disable only the fuel pump?

Nope , not the 20A inline fuse .

See how it feeds not only the fuel pump , but feeds the ECM as well ? If you pull that fuse your ECM will loose power and I doubt it will run the injectors with that fuse missing (try it , I could be mistaken but I'm pretty sure the ECM won't function without that fuse) .

If that fuse does kill the ECM so you injectors won't pulse , the next thought would be to unplug both the fuel pump relay and the pump's oil pressure switch , both really easy to get to , and that will kill your pump (and if you have the "all in one" pressure switch/gauge sender the oil gauge won't function while it's unplugged) without killing anything else but possibly the oil gauge .

PS , it looks like your MAF relay receives power from the fuel pump circuit so unplugging the switch & relay will result in no power to the MAF relay . It should still run , but it will throw a MAF code that will need to be cleared when you hook back up the switch & relay at the end of your procedure .

Last edited by OrangeBird; Mar 2, 2017 at 11:10 AM. Reason: edited to add the comment about the MAF
Reply
Old Mar 2, 2017 | 01:16 PM
  #5  
Tuned Performance's Avatar
Sponsor
20 Year Member
Community Builder
Community Influencer
Community Favorite
iTrader: (94)
 
Joined: Dec 2004
Posts: 16,737
Likes: 994
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: How to disable only the fuel pump?

Pull the ops connecter off.
Reply
Old Mar 2, 2017 | 03:16 PM
  #6  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: How to disable only the fuel pump?

What is the ops connector?

Is there a connector near the back of the car that is easy to access?

Found this:

Connector C313: Below Center Of Rear Seat
Connector C207: Behind RH Side Of I/P, Near ECM

Last edited by Tootie Pang; Mar 2, 2017 at 03:21 PM.
Reply
Old Mar 2, 2017 | 03:20 PM
  #7  
Tuned Performance's Avatar
Sponsor
20 Year Member
Community Builder
Community Influencer
Community Favorite
iTrader: (94)
 
Joined: Dec 2004
Posts: 16,737
Likes: 994
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: How to disable only the fuel pump?

Oil pressure switch, there is the fuel pump connecter in front of the gas tank.
Reply
Old Mar 2, 2017 | 03:48 PM
  #8  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: How to disable only the fuel pump?

Awesome, I'll look for that!
Reply
Old Mar 2, 2017 | 03:52 PM
  #9  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: How to disable only the fuel pump?

From my manual:
As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump.

Bottom line: The fuel pump should be disabled at the fuel pump connector.



Last edited by Tootie Pang; Mar 2, 2017 at 03:55 PM.
Reply
Old Mar 2, 2017 | 05:13 PM
  #10  
Tuned Performance's Avatar
Sponsor
20 Year Member
Community Builder
Community Influencer
Community Favorite
iTrader: (94)
 
Joined: Dec 2004
Posts: 16,737
Likes: 994
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: How to disable only the fuel pump?

Originally Posted by Tootie Pang
From my manual:
As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump.

Bottom line: The fuel pump should be disabled at the fuel pump connector.


The relay is only there for ecm control of the 2 second prime.
After that cranking 4psi of oil pressure power directly from the fused battery lead goes to the pump.(not really a backup!).
Reply
Old Mar 3, 2017 | 10:52 AM
  #11  
Tootie Pang's Avatar
Thread Starter
Supreme Member
15 Year Member
iTrader: (2)
 
Joined: Aug 2009
Posts: 1,972
Likes: 127
From: Los Angeles
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: How to disable only the fuel pump?

I found the connector to the fuel pump and level sender unit right above the rear axle pumpkin and the body panel. Easy to get to and worked like a charm. Thanks everyone. Got my injectors cleaned out.
Reply




All times are GMT -5. The time now is 07:21 AM.