Welcome to the North American Subaru Impreza Owners Club Thursday August 27, 2015
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Built Motor Discussion

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 08-04-2007, 01:56 PM   #1
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default How does a car idle without a fuel pump?

I just created a thread about unflooding a motor, so I did what jeremy from cobb told me to do, I cranked the motor over by hand, then I replaced the spark plugs. I tried to start it no go......So I disconnect the fuel pump and she will idle????? My question is how does a car idle with the fuel pump relay disconnnected?????? What should I do to keep it running with the fuel pump working? someone let me know. Is it safe to run with the fuel pump disconnecting jsut to idle. Also, is it ok to plug the fuel pump in while the car is idling????

Thanx
Eric
* Registered users of the site do not see these ads.
railguy is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 08-04-2007, 04:29 PM   #2
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default

Ok ,well i plugged the fuel pump in when the car is running and it just dies.....I have an aftermarket dual walboro fuel. What is going on????I am thinking a draw.....but at what point does the utec kick in and control fuel? Could a bad injection cause this?
railguy is offline   Reply With Quote
Old 08-04-2007, 05:19 PM   #3
Starkiller
Scooby Specialist
 
Member#: 82741
Join Date: Mar 2005
Chapter/Region: NESIC
Location: Bristol, CT
Vehicle:
2007 350Z Silver

Default

Just a guess, but it probably has something to do with your wiring of the fuel pumps. Maybe its causing the ECU think that theres fuel pump trouble and it kills the engine to prevent damage. IIRC, UTEC doesn't kick in until a certain RPM/Throttle position is reached, ie the OEM fuel/timing map controls idle.\

Although if I'm wrong, someone will chime in and say otherwise
Starkiller is offline   Reply With Quote
Old 08-05-2007, 12:19 AM   #4
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

you have a post turbo intake leak. It's most likely your intercooler tubing is either popped off, or a REALLY bad manifold leak.

check all your connections, specifically look behind the bumper....don't say it's "all ok". pressure test the damn system.


p.s. I hope you have a fmic.



ppssps... plug in your fuel pump....then unplug your maf sensor....if it starts and runs just fine.....guess what...you have a post turbo intake leak

other than that, I can't help you
modaddict is offline   Reply With Quote
Old 08-05-2007, 12:52 AM   #5
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default

How bad is really bad? I remember back in the day, I had a leak from where the injector seats the intake manifold. But it still ran just idled a little bit high and I pretty sure I fixed it. I will unplug the maf and see what happens.
railguy is offline   Reply With Quote
Old 08-05-2007, 01:08 AM   #6
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

Quote:
Originally Posted by railguy View Post
How bad is really bad? I remember back in the day, I had a leak from where the injector seats the intake manifold. But it still ran just idled a little bit high and I pretty sure I fixed it. I will unplug the maf and see what happens.
idled high? you must have been running a speed density system instead of maf based?


bad meaning......pretty bad. I had the exact same issue as you with flooding of the engine. My wife was driving my car and she said she didn't hear a thing...but my intercooler tube popped off behind the bumper. It took me awhile to find it, but unplugging the fuel pump, the car would start and run for ATLEAST 30 seconds, because it was sooooo flooded. I eventually found that when you unplug the maf, and pump plugged in, the car ran great! just no boost!

MAKE SURE TO CHANGE YOUR OIL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

this is what happens when and intercooler tube pop's off going down the highway and your wife hears nothing:




modaddict is offline   Reply With Quote
Old 08-05-2007, 09:05 AM   #7
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default

well, sir I unplugged maf and tried to start, the car wont run with the fuel pump enguaged..........unplug the pump and it runs great......I even tried to start it with the maf unplugged and the fuel pump unplugged, got it to idle then plugged fuel pump back in. Killed the motor instantly.................and I almost 99% sure that I have no hose to intercooler coming off.
railguy is offline   Reply With Quote
Old 08-05-2007, 11:58 AM   #8
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

when unplugging the pump and then running the vehicle, will it die after 30 seconds or so? If it does, THEN plug in the pump and unplug the maf.

Are you blowing smoke out the tailpipe when the pump plugged in? is the vehicle basically misfiring and then dying because it runs soo rich?
modaddict is offline   Reply With Quote
Old 08-05-2007, 06:46 PM   #9
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default

The car does not die, it will idle forever....... it is smoking but you can tell its from the fuel. I do not have any cel for misfires.......
railguy is offline   Reply With Quote
Old 08-05-2007, 09:17 PM   #10
railguy
Scooby Specialist
 
Member#: 53756
Join Date: Jan 2004
Chapter/Region: MAIC
Location: MAIC
Vehicle:
2002 WRX
WRB

Default

well, i believe now that it is because the car is not tuned and my 1000cc injector map for my fpred is not enough......... I think its a tuning issue.
railguy is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Can you run without the fuel pump controller?? eightballrj Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 1 10-13-2003 03:20 AM
What RPM does your car idle on? KAuss Bay Area Impreza Club Forum -- BAIC 16 09-12-2002 02:39 AM
What RPM does your car idle at? sbsnyder Normally Aspirated Powertrain 13 05-29-2001 12:50 AM
('93-'01) how does a high idle (900-950) affect the RS? popnGEAR Impreza Forum 0 04-16-2001 08:38 PM
Higher Idle with larger fuel pump? yebokmj Normally Aspirated Powertrain 1 03-08-2001 03:57 PM


All times are GMT -4. The time now is 08:27 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2015, North American Subaru Impreza Owners Club, Inc.