Print Page | Close Window

fuel pump wiring

Printed From: West Coast Fieros
Category: Technical Topics Forum
Forum Name: Technical Questions and Discussions
Forum Description: Got a technical question about your fiero? ask it here.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=2194
Printed Date: 24 April 2025 at 11:15pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com


Topic: fuel pump wiring
Posted By: cam2510
Subject: fuel pump wiring
Date Posted: 23 November 2010 at 4:15pm
problem:
fuel pump or injectors(have receipts previous owner for new injectors 6 years ago, cars sat on and off for 10) are draining pressure and causing hard start till the oil pressure rises then starting the fuel pump.

my check/solution:
if its the fuel pump since it works great once on and we cannot find a leak would be to set up a signal on the ignition to fuel pump so the fuel line will pressurize rather then waiting for the normal signal when the oil pressure rises.

in theory it shall work even if I have to wire up a push button it will eliminate 2sec of the hard starts unfortunately i have no idea where to start! so am I correct in my thoughts? and how might i attack this without the huge costs of overhauling a fuel system on a dying engine?



Replies:
Posted By: Patrick
Date Posted: 23 November 2010 at 4:37pm

Originally posted by cam2510 cam2510 wrote:

problem:
fuel pump or injectors(have receipts previous owner for new injectors 6 years ago, cars sat on and off for 10) are draining pressure and causing hard start till the oil pressure rises then starting the fuel pump.

Are you saying your fuel pump is not priming as soon as you turn your ignition key?

Fix that problem first!

 



Posted By: Romeo
Date Posted: 23 November 2010 at 7:17pm

Yeah, your fuel pump doesn't care about your oil pressure, it should prime itself as soon as the key is moved the 'on' position.

If you turn the key to 'on' without starting the engine a few times, and then try starting, does it fire up quicker?



-------------
Never shift into reverse without a back-up plan.


Posted By: Capt Fiero
Date Posted: 23 November 2010 at 8:58pm

Just a side note, like everyone said, the pump should prime with ignition, if it does not, replace the fuel pump relay.

Romeo, yes the car does sense oil pressure and does fire the fuel pump as a backup if the fuel pump relay has gone south.



-------------
Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.


Posted By: cam2510
Date Posted: 24 November 2010 at 3:59am
yes in the morning when pressure has left the lines I have to turn the engine over till there is oil pressure then she starts up like a dream for the rest of the day, and no the key doesn't fire the fuel pump at all it seems relient on oil pressure.

alright relay it is... I so have no idea where too look, first fuel injection ive worked on.. is it just in the relay panel? phone in the morning see whats available...

the way it was explained i was in belief that the sensor only kicked after the oil pressure....sounded funny to me

how would i find where the pressure is leaking? just replace the injectors then work back to the pump? i've heard injectors difficult too "test"?

side note I dont think im equiped for injectors..


Posted By: Romeo
Date Posted: 24 November 2010 at 7:37am
Originally posted by Capt Fiero Capt Fiero wrote:

Just a side note, like everyone said, the pump should prime with ignition, if it does not, replace the fuel pump relay.

Romeo, yes the car does sense oil pressure and does fire the fuel pump as a backup if the fuel pump relay has gone south.


There isn't any oil pressure when priming...

-------------
Never shift into reverse without a back-up plan.


Posted By: Dawg
Date Posted: 24 November 2010 at 11:53am
Dave is right, I just went through this myself.  The oil sender has a switch in that will run the fuel pump if the relay malfunctions.  But I bet you need to crank it a bit before much pressure reaches the sender.

The relay should be behind the air cleaner on the firewall.

I'm not sure you have any more leaking than normal.  Try replacing the relay and go from there.


The Dawg


-------------
You dream it up....I'll make it


Posted By: cam2510
Date Posted: 24 November 2010 at 2:06pm
relay is done she fires up like a dream



Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.01 - http://www.webwizforums.com
Copyright ©2001-2018 Web Wiz Ltd. - https://www.webwiz.net